cnc machine design report

CNC Machine Design Report

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Project 24

Submitted By:

Team: F09-24-CNCMACHD


Prepared for: Saluki Engineering Company

Team Members:

James Williams (PM) EE/CompE

Shawn Gossett EE

Eric Blankenship EE/CompE

Glenn E Spiller II CompE

Pat Brokaw ME

Brian Hagene ME


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Acknowledgements

Saluki Engineering Company’s Team 24 would like to thank these

individuals for their input and support in proposing and designing the project.

Dr. Frances Harackiewicz

Dr. William Osborne

Mrs. Kay Purcell

Dr. Alan Weston

Dr. Haibo Wang- Faculty Technical Advisor

Mr. Mark Hopkins- Technician/ Field Engineer for Allegro Micro-devices

Saluki Engineering Company’s Team 24 would also to thank these

individuals and their respective companies for their donations to accomplish the construction of the project.

Mr. Howard Everton- President of Norva Plastics

Barb Saathoff- Representative from Dytronix


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1. Table of Contents 2. Introduction ........................................................................................................................................ 13

2.1 Main Block Description ............................................................................................................... 13

2.2 Options Considered and Chosen Option ..................................................................................... 14

2.2.1 Mechanical Subsystem ........................................................................................................ 14

2.2.2 Main Controller Subsystem ................................................................................................. 15

2.3 Expected and Achieved Performance Data ................................................................................ 15

2.4 Limitations................................................................................................................................... 15

2.5 Summarization of Fault Analysis ................................................................................................. 16

3. Mechanical Subsystem........................................................................................................................ 17

3.1 Deflections .................................................................................................................................. 17

3.1.1 X-axis ................................................................................................................................... 17

3.1.2 Z-axis ................................................................................................................................... 18

3.1.3 Y-axis ................................................................................................................................... 19

3.2 Mechanical Drive System ............................................................................................................ 19

3.2.1 Ballscrew Lead Specification ............................................................................................... 19

3.2.2 Ballscrew Linear Force and Torque ..................................................................................... 19

3.2.3 Thrust Force ........................................................................................................................ 20

3.3 Table Top Support Calculations .................................................................................................. 20

3.4 Tool Heads .................................................................................................................................. 21

3.4.1 Spindle Mount ..................................................................................................................... 21

3.4.2 Solder Paste Dispenser........................................................................................................ 21

3.5 Machine Electronics .................................................................................................................... 22

3.5.1 Cable Carrier ....................................................................................................................... 23

3.5.2 Electrical Component Housing ............................................................................................ 23

3.5.3 Pendant Case ...................................................................................................................... 23

3.6 Equipment Lists ........................................................................................................................... 23

3.6.1 Design Tools ........................................................................................................................ 23

3.6.2 Machining and Assembly Tools ........................................................................................... 23

3.7 Components and Specifications .................................................................................................. 24


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3.7.1 Material Specifications ........................................................................................................ 24

3.8 Components ................................................................................................................................ 24

3.8.1 Z-axis ................................................................................................................................... 24

3.8.2 X-axis ................................................................................................................................... 26

3.8.3 Base ..................................................................................................................................... 27

3.8.4 Y-axis ................................................................................................................................... 28

3.8.5 Tool Heads........................................................................................................................... 29

3.8.6 Machine Electronics ............................................................................................................ 31

3.8.7 Additional Components ...................................................................................................... 31

3.9 Data Sources ............................................................................................................................... 32

3.9.1 Websites .............................................................................................................................. 32

3.10 Fault analysis ............................................................................................................................... 32

3.10.1 Fastener and Component Failures ...................................................................................... 32

3.10.2 Excessive Wear .................................................................................................................... 32

3.11 Health & Safety, Environmental, Life Cycle, and Societal Issues ................................................ 33

3.12 Engineering Drawings ................................................................................................................. 33

4. Electrical .............................................................................................................................................. 34

4.1 Motor Driver Board ..................................................................................................................... 34

4.1.1 Scope ................................................................................................................................... 34

4.1.2 Block Diagram ..................................................................................................................... 34

4.1.3 Technical Description .......................................................................................................... 36

4.1.4 .................................................................................................................................................... 41

4.1.5 Health and Safety ................................................................................................................ 44

4.1.6 Equipment Required ........................................................................................................... 45

4.1.7 Schedule Data for Driver Board .......................................................................................... 45

4.1.8 Test, Measurement and Fault Analysis ............................................................................... 45

4.1.9 .................................................................................................................................................... 46

4.1.10 Section Summary ................................................................................................................ 49

4.2 Main Controller Schematic ......................................................................................................... 50

4.2.1 Communication Controller.................................................................................................. 50


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4.2.2 CPLD Connections ............................................................................................................... 58

4.2.3 Timing for the CPLD ............................................................................................................ 59

4.2.4 Power supply ....................................................................................................................... 59

4.3 Pendant Subsystem ..................................................................................................................... 61

4.3.1 Introduction ........................................................................................................................ 61

4.3.2 Hardware Subset ................................................................................................................. 61

4.3.3 Schematic Design ................................................................................................................ 61

4.3.4 PCB and Physical Layout...................................................................................................... 62

4.3.5 Physical Display after Button Press ..................................................................................... 65

5. Firmware ............................................................................................................................................. 66

5.1 Communication Controller: ........................................................................................................ 66

5.1.1 Listening State: .................................................................................................................... 67

5.1.2 Preamble State: ................................................................................................................... 67

5.1.3 Receiving State: ................................................................................................................... 67

5.1.4 Group ID .............................................................................................................................. 68

5.1.5 Post-amble State: ................................................................................................................ 70

5.2 Motion Controller Micro-Processor Code ................................................................................... 71

5.2.1 Events .................................................................................................................................. 71

5.2.2 Initialization ......................................................................................................................... 71

5.2.3 Parameter Table .................................................................................................................. 72

5.2.4 Global Table ........................................................................................................................ 73

5.2.5 Commands .......................................................................................................................... 74

5.2.6 Motion Controllers data flow .............................................................................................. 76

5.2.7 Interrupts ............................................................................................................................ 78

5.2.8 Files in the Motion Controller Program .............................................................................. 79

5.2.9 Bresenham Algorithms ........................................................................................................ 81

5.3 Firmware Subset ......................................................................................................................... 83

5.3.1 Interrupts ............................................................................................................................ 83

5.3.2 Driver Subset ....................................................................................................................... 84

5.3.3 Display Driver ...................................................................................................................... 87


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5.3.4 Analog Driver ...................................................................................................................... 90

5.3.5 Serial Driver ......................................................................................................................... 91

5.3.6 Main Subset ........................................................................................................................ 92

5.3.7 Function Sub-block .............................................................................................................. 94

5.3.8 Jog Sub-block....................................................................................................................... 95

5.3.9 Cancel Sub-block ................................................................................................................. 96

5.3.10 Accept Sub-block ................................................................................................................. 97

5.3.11 Directory Block .................................................................................................................... 98

5.3.12 Graphics ............................................................................................................................ 100

5.3.13 Screens .............................................................................................................................. 101

5.3.14 Relation To Other Sub-Systems ........................................................................................ 109

6. Conclusions and Recommendations ................................................................................................. 110

6.1 Conclusions ............................................................................................................................... 110

6.2 Recommendations .................................................................................................................... 110

7. Cost/Manufacturability ..................................................................................................................... 111

Materials ............................................................................................................................................... 112

7.1 Mechanical Cost ........................................................................................................................ 113

7.2 Electrical Cost ............................................................................................................................ 120

8. APPENDIX A ....................................................................................................................................... 125

8.1 VGA Data Sheet ......................................................................................................................... 125

8.1.1 MoveTo() ........................................................................................................................... 126

8.1.2 EraseScreen ....................................................................................................................... 126

8.1.3 SetBackground() ................................................................................................................ 126

8.1.4 DrawLine() ......................................................................................................................... 126

8.1.5 SetFontSize() ..................................................................................................................... 127

8.1.6 DrawBox().......................................................................................................................... 127

8.1.7 OpaqueTransparent() ........................................................................................................ 127

8.1.8 PlaceText() ......................................................................................................................... 127

8.1.9 WriteString() ..................................................................................................................... 127

8.1.10 DisplayImage() .................................................................................................................. 128


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8.1.11 PaintArea() ........................................................................................................................ 128

8.1.12 DrawCircle() ...................................................................................................................... 128

8.1.13 SetColumn() ...................................................................................................................... 128

8.1.14 SetRow() ............................................................................................................................ 129

8.1.15 SetRowColumn() ............................................................................................................... 129

8.1.16 PlaceCharUnFor() .............................................................................................................. 129

8.2 3.1 Screens ................................................................................................................................ 129

9. APPENDIX B ....................................................................................................................................... 130

9.1 X-axis ......................................................................................................................................... 130

9.2 Y-axis ......................................................................................................................................... 131

9.3 Calculated Moments and Equivalent Force Couples on X Rails ................................................ 131

9.4 Trade off Study: 3 rods vs 4 rods, Rod Spacing ......................................................................... 133

9.4.1 3 Rod Configuration .......................................................................................................... 133

9.4.2 4 Rod Configuration .......................................................................................................... 135

9.5 Table Top Support Calculations ................................................................................................ 136

9.5.1 Table Support Calculations ............................................................................................... 136

9.6 Ballscrew Calculations ............................................................................................................... 137

9.6.1 Ballscrew Calculations ....................................................................................................... 137

9.7 Cable Carrier ............................................................................................................................. 138

9.7.1 Cable Carrier Selection ...................................................................................................... 138

9.8 Solder Paste Dispenser ............................................................................................................. 138

9.8.1 Equations .......................................................................................................................... 138

9.8.2 Solution: General Engineering Equation ........................................................................... 139

9.8.3 Flow Locations ................................................................................................................... 140

9.8.4 Solution: Force Approximation ......................................................................................... 140

9.9 Design Notebook: Pat Brokaw .................................................................................................. 140

9.9.1 Table of Contents .............................................................................................................. 140

9.10 Cost Data and Schedule Data .................................................................................................... 143

9.10.1 Prototype Cost .................................................................................................................. 143

9.11 Manufacturing Costs and Schedule .......................................................................................... 150


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9.11.1 Equipment Costs ............................................................................................................... 150

9.11.2 Material Costs ................................................................................................................... 153

9.11.3 Fasteners ........................................................................................................................... 160

9.11.4 Component Data Sheets ................................................................................................... 163

10. APPENDIX C ....................................................................................................................................... 166

10.1 Pendent Code Datasheet .......................................................................................................... 166

10.1.1 Graphics Header File: ........................................................................................................ 166

10.1.2 Graphics Source File: ......................................................................................................... 168

10.1.3 Screens Header File: .......................................................................................................... 172

10.1.4 Screens C Source file: ........................................................................................................ 174

10.1.5 Support Source File: .......................................................................................................... 183

11. APPENDIX C ....................................................................................................................................... 184

11.1.1 Test Data ........................................................................................................................... 184

11.1.2 Calculations Section .......................................................................................................... 191

11.1.3 List of Figures .................................................................................................................... 203

11.1.4 Simulations ........................................................................................................................ 206


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Saluki Engineering Company

Senior Engineering Design

College of Engineering – Mailcode 6603

Carbondale IL 62901-6603

618-453-7837, -7031, -7025, -7642

Transmittal Letter

27 April 2010

Subject: CNC Machine Design Client: Engineering Innovations, Inc.

Project Number: F09-24-CNCMACHD

The CNC Machine that was requested by Engineering Innovations, Inc. has been designed,

tested, and built into a prototype by Team 24 of the Saluki Engineering Company. The

prototype can successfully perform different functions of manufacturing through one of three

different communication links that can interpret multiple file types. Attached, you will find the

design report to aid in understanding the creation of the machine. Also attached in a separate

packet, there is a user’s manual to help anyone understand how to assemble, connect, and

correctly operate the machine, and there is a technician’s manual to provide information to a

trained specialist to find and correct any problems that may occur during operation of the

machine. We request that you be very careful while operating the machine and completely

read the user’s manual before starting any job.

We would like to thank you for having interest in working with Saluki Engineering Company,

and if there are any further questions feel free to contact the project manager, James Williams,

at 618-937-8521.

Sincerely,

James Williams- Project Manager

Shawn Gossett- Secretary

Executive Summary


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The CNC Machine is a system that can be used not only by manufacturers

but also by small scale hobbyists. It has been designed with these features.

Microcontroller system to send and receive information

Driver system to run machine at desired specifications

Hand pendant system to access information and manipulate machine

Mechanical system to support weight of gantry while in motion or idle plus the weight of the attached tool heads, handle deflection, and prevent thermal expansion

This machine has these advantages over similar products.

Three forms of communication either through serial port, Ethernet, or USB jump drive

Controllable through a specially designed hand pendant

Multiple tool heads for different applications including milling, paste dispensing, and air brushing

Accepts multiple types of files

Able to move at high speeds

Longer working life compared to other relative machines

Costs much less than competitors

Easy to assemble, operate, and maintain

This document contains a report with all relevant material concerning the

design of the entire machine. The report will be broken down into these sections

Overall description of system

Sub-system design

Cost Estimate


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Implementation Schedule

Conclusion with discussion of design

Complete time for implementation of the machine will be approximately 13

weeks, and it would have a total cost of $1814.


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2. Introduction

2.1 Main Block Description

The CNC machine is a system that is able to accept numerical control inputs

to machine a part specified by the exact positioning of the inputs. The machine is

able to accept commands either through a directly connected personal computer

or a flash drive that is activated through the pendant subsystem. The personal

computer is allowed three direct forms of communication to the main controller

subsystem either through Ethernet, USB, or serial link. The main controller

subsystem is able to interpret and communicate the limits of any job, and it can

directly control movement of the attachable tool heads. With direct connection to

the main controller subsystem, the pendant subsystem is able to accept jobs

uploaded through a flash drive, access information incoming through one of the

three communication ports that are active, and can change specified rates of

speed and the direction of movement of the machine. The framework of the

system is set up by the mechanical subsystem which will allow for movement in

the x, y, z axes and specify spatial limitations of any acceptable job. The main

controller, pendant, and mechanical subsystems are able to interact through

power provided by the motor driver subsystem. The motor driver subsystem will

contain a power supply that can accept input power through an electrical outlet

plug-in, provide movement independently to the x, y, z axes, and can add an extra

board to power the acceleration axis. The overall block diagram of the machine is

pictured below.


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Personal

Computer Main

Controller

Board

Pendant

Motor

Power

Supply

Motor

Driver

Board

A Axis

Driver

Board

Table

Motor

1

Motor

2

Motor

3

Motor

4

Tool

head

Limits

Ethernet

USB

Serial

Flash Drive

Figure 1: Overall Block Diagram

2.2 Options Considered and Chosen Option

2.2.1 Mechanical Subsystem

In consideration of the mechanical subsystem, there were two different

aspects of the design that had to be considered before implementation of the

design. These two aspects are listed below.


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Materials of the structure

Railing of the table

The materials of the structure options were between aluminum and high

density polyethylene. The chosen option for the materials was the high density

polyethylene because of the decrease in total weight of the entire system, less

cost, and the dampening of vibrations caused by mechanical movement.

The railing of the table options were between versa railing and rod railing.

The chosen option for the railing was the rod railing because it had a high

decrease in costs compared to its counter-part.

2.2.2 Main Controller Subsystem

In consideration of the main controller subsystem, there is one aspect that

was considered before implementation of the design that is listed below.

Microprocessor

The microprocessor of the controller was between the PIC 24 and the

Atmel. The chosen option for the microprocessor was the PIC 24 because of

its less cost, its availability of development tools, its easier level of

programming for the instruction set, and its greater reliability.

2.3 Expected and Achieved Performance Data

The two main performance data statistics are for the machine’s

acceleration rate and velocity rate. The expected performance of both rates was

anticipated to be 4 inches per second. After designing and testing, the achieved

rates were within a small deviation for both rates expected values.

2.4 Limitations

The machine is limited by only two factors. These factors are types of

materials that can be cut and the total weight of the tool head. The cutting


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material is only allowed to light metals, wood, and circuit boards. The tool head

weight can not exceed 5 pounds.

2.5 Summarization of Fault Analysis

As of this date, the faults detected in the motor driver subsystem do not

affect overall system performance, and no other faults can be detected in the

system without further testing.


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3. Mechanical Subsystem The mechanical subsystem includes the CNC machine and all of its components. This consists of the

machine frame, the gantry for each axis, the work table, and the interchangeable tool heads. This

subsystem produces a machine that has three dimensions of reliable and precision motion and allows

milling, silk screening, and paste dispensing to be done to a part that has been fixed to the work table.

Each axis has been supported by precision guide rails and driven linearly by ballscrews. The ballscrews

provide axis motion by transferring torque from the three separate stepper motors. These motors are

powered by the Power Drive Electronics subsystem and controlled by the Main Controller subsystem.

3.1 Deflections The most significant purpose of the mechanical design was to provide three gantries that would

allow precision to be maintained in the tool head position. In order to obtain this, a maximum allowable

deflection of 0.001 inch was set for each guide rail. Each axis was designed to support its weight and

withstand the force incurred during milling while maintaining this deflection tolerance.

3.1.1 X-axis

3.1.1.1 Calculated Moments and Equivalent Force Couples on X Rails

This iterative design process began with the determination of the deflection in the x-axis. The x-axis

provides motion across the width of the table and must support both the weight of the vertical

axis(z-axis) and withstand the cutting force. Because the x-axis crosses the table, it required the use of

unsupported precision rail and was susceptible to the largest deflection. In order to find the deflection

of the x-axis rails, a tentative design for the z-axis was done and the weight of each component,

including a 10lb tool head, was multiplied by the distance from its center of gravity to the center of the

x-axis ballscrew. These were summed in appendix Table 1.4-1 to find a moment due to the weight of the

z-axis of approximately 100 lbs.in. Then, the maximum cutting force experienced by the tool head when

extended fully to the table was set at 5.5 lbs and multiplied by the vertical distance. This calculation,

shown in Table 1.4-2, produced a 75 lbs.in moment.

With the calculated moments, the resultant forces experienced by each rail was then determined.

Since the ballscrew is centered between the rails, the resultants produce force couples in the horizontal

and vertical directions that are equivalent to the moments of the cutting force and the z-axis weight,

respectively. Each resultant was found by dividing the moments by the spacing of the horizontal and

vertical spacing of the rails as shown in Table 1.5-1 and Table 1.5-3. Table 1.5-1 and Table 1.5-3 also

show that the effect of increasing the spacing between the rails was a decrease in the resultant force

experienced by each rail. The final spacing was set at 4 in as a compromise between reduced forces and

a compact x-axis design.


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3.1.1.2 Trade off Study: 3 rods vs 4 rods

The force resultant is reduced further with the use of three and four rails. Tables 1.5-2 and 1.5-4

show the rod orientation with three and four rail designs, respectively. From Table 1.5-1 showing the

configuration for three rails, the moment due to weight is balanced by a vertical force couple where

each force is F1 and the moment due to the cutting force is neutralized by a horizontal force couple with

each component as F2. Rod 1 experiences all of the vertical force, F1, while rods 2 and 3 only hold half

of this force component because both are aligned. The horizontal force component is split between rods

1 and 2 while rod 3 experiences the entire force. After determining the horizontal and vertical forces on

each rod, a resultant was found for each and is shown in Table 1.5-1. The top rear rail experienced a

26.70 lb force, while the top front and bottom rails were loaded with 15.63 lb and 22.53 lb forces

respectively. These resultants are presented more clearly in Table 1.5-2 in the cell corresponding to the

orientation of the rod. In addition, a free body diagram sketch can be referenced on page 31 of Pat

Brokaw’s design notebook.

When four rods are used, both components of the force couple are divided between two rods. This

reduces the resultant force on each rod even further to 15.63 lbs each. A comparison was done between

the configuration for three rods and four rods was done in order to determine if this additional

reduction in force justified adding a fourth rod. This first required a comparison of the minimum rod

diameter allowable for a three and four rod design.

3.1.1.3 Rod Diameter Selection

The rod diameter required to support a given weight was found using the deflection equation given

in Figure 1.1-1 (Budynas). This equation, applied twice, best represents the x-axis deflection problem

because the rod has fixed supports with two point forces applied at the bushing locations. Table 1.2-1

shows this calculation with the modulus of elasticity set at 29x106 psi, the maximum deflection set at

0.001 in, the length of the rail at 30 in, and the forces separated by the center to center distance of the

bushings of 1.3125 in. The force that results in a 0.001 in deflection was found for rod diameters of 0.75

in to 1.25 in.

It was determined that the 1 in rod only supported 19.4 lbs and the next available rod size of 30mm,

or 1.18 in, supported 37.8 lbs at a deflection of 0.001 in. With these numbers, it was found that with

three rods a one inch rod was insufficient to support the load and the 30mm rod diameter was required.

However, if four rods were used the 15.63 lb force on each rail could be supported by the 1 in diameter

rod. Then, the final comparison involved cost. The costs include the expense of the rails, the bushings,

and the additional machining required for the additional rod. It was determined from this analyze that a

3 rod configuration would be less expensive and ultimately the most desirable design.

3.1.2 Z-axis

In the process of evaluating the deflections in the x-axis, it was apparent that the horizontal distance

between the tool head’s center of gravity and the x-axis ballscrew was a significant factor in the

calculated moment. It was determined that reducing this distance would greatly reduce the moment


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due to weight. For this reason, the versa rails were selected as the linear guides for the vertical axis. The

height of rail system from the bottom of the rail to the top of the bearing block was 1.18 in and the total

including the standoffs was 1.6024 in. A cross-sectioned sketch of this axis can be found on page 36 of

Pat Brokaw’s design notebook. This reduced the moment and because the versa rails are capable of

dynamic loads of 2449 lbs, all deflection concerns in the z-axis were eliminated.

3.1.3 Y-axis

The deflections in the y-axis guide rails were also an area of concern. The rails are mounted beneath

the work table and the y-axis provides motion along the length of the table. The force that it must

support is solely due to the weight of the z-axis and x-axis gantries. This weight is near 100lbs and must

be supported on a 38 in long rail. Table 1.3-1 shows the force required to deflect a rod of this length

0.001 in and compares the forces for rod diameters from 0.75 in to 1.25 in. From the calculations in

Table 1.3-1, it was determined that this tolerance could not be held by a linear rail alone and a

supported guide rail system must be used for this application.

3.2 Mechanical Drive System

3.2.1 Ballscrew Lead Specification

Once the linear guides for each axis were designed to hold the desired deflection tolerance, the

mechanical drive system was examined. The mechanical drive utilizes ballscrews to convert the torque

from the drive motors into linear motion. Ballscrews use circulating ball bearings within the nut which

act to eliminate frictional losses and reduce wear in comparison to other linear motion alternatives,

namely ACME threaded power screws. A precision of 0.001 in was desired in the linear motion of the

tool head and a ballscrew with a lead of .200 in/rev was selected. As explained in the Power Drive

Electronics subsection, microstepping is used to turn the ballscrew in increments small enough to

achieve this precision.

3.2.2 Ballscrew Linear Force and Torque

Next, the forces transmitted linearly through the ballscrew were calculated in order to validate the

diameter selected and determine a method for mounting the ballscrew. Table 3.1-1 shows the

specifications of the ballscrew and some of the operating conditions considered. Two conditions were

considered when the machine was accelerating and when operating at a constant velocity. The force

exerted on the ballscrew is equivalent to the acceleration force and the force of friction that must be

overcome when moving along the gantry. When accelerating, the static coefficient of friction was used

and the force of acceleration is added to the frictional force. When moving at a constant velocity, only

the frictional force is present and the kinetic coefficient of friction was used.

Since the y-axis carries the greatest weight, it was used to determine the maximum forces on the

ballscrews. As shown in Table 3.1-1, the static friction force was 25 lbs and the force of acceleration was

3.88 lbs. This converts to a torque of 16.3 oz.in. When moving at a constant velocity, the ballscrew must

overcome a kinetic friction force of 18.75lbs by providing a torque of 10.6 oz.in. An acceleration of 15


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in/s2 was set for machine operation and the time to accelerate to various velocities was determined.

This was used in a separate equation provided by Roton, the ballscrew manufacturer, and it was

confirmed that the force remained constant at 3.89 lbs if the acceleration is kept at 15 in/s2.

3.2.3 Thrust Force

The linear force carried by the ballscrew is the thrust force that must be carried by the bearings and

the gantry sides. The ballscrew was supported by a roller bearing on one end and was fixed on the other

using a thrust bearing block assembly shown in Figure 3.3-1. A preliminary sketch of this assembly is a

shown on page 39 of Pat Brokaw’s design notebook and final engineering drawing of the thrust bearing

block is present as drawing number B-13. One thrust bearing was placed between the shaft step and the

thrust bearing block. Then another thrust bearing was pressed into the other side of the thrust bearing

block and a nut was tightened on the shaft threads to remove all free play in the bearings. This

effectively removed all linear play in the ballscrew when the thrust bearing block is mounted to the side

of the gantry. In addition, seals were placed on either end of the bearing block and a greases zerk was

threaded into the side to allow for routine lubricating of the thrust bearings.

Figure 3.2-1

With the ballscrew fixed with the thrust bearing block, all linear forces are then transferred to the

gantry sides. Each gantry side was fixed solidly, and it was determined that each axis would be able to

handle this thrust force. For example, each x-axis rod is mounted with a 3/8 in bolt threaded into the

end and the uprights are constructed of ¾ in high density polyethylene quite capable of withstanding

this thrust force. Additional finite element analysis for each gantry end is certainly desirable to confirm

this observation. However, the expertise was not available among the team’s mechanical engineers and

unfortunately time did not allow for the skills to be obtained and applied for this project. In future

considerations, this will certainly be an area of focus.

3.3 Table Top Support Calculations The design of the gantry guide rails and the ballscrew drive system provide precise motion of the

tool head. Additional calculations were then done to ensure that when a part is placed on the table it is

held accurately in position and that no deflections are experienced in the work table. The table top is

constructed of 0.5 in high density polyethylene provided by Norva Plastics. This offers ease of


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construction, superb appearance, and acts to dampen vibrations. However, the maximum allowable

weight of a part placed on the table without deflection is minimal. In order to allow milling to be done to

larger stock and to maintain tolerances when tooling inflicts downward forces, such as in drilling

applications, additional supports were needed under the table.

It was determined that three rectangular, steel supports would be distributed evenly beneath the

table. The calculation that justified this decision is shown in Table 2.1-1 and was done using the

deflection formula shown in Figure 1.1-1, which was used previously for the guide rail deflections.

However, in this case the second moment of area was changed appropriately for a rectangular beam. It

was determined that a rectangular rail with dimensions, 0.375 in by 1.00 in, provided an additional 6.1

lbs of support per rail if the part weight is approximated as two point forces separated by 1.3125 inches.

This allows for a piece of metal stock in excess of 18 lbs to be placed in the center of the table without a

deflection greater than 0.001 in.

3.4 Tool Heads With a precision machine and a well supported table designed, attention was turned to the

functionality of the machine. This includes the tool heads available for attachment to the z-axis. The

machine is intended to be multifunctional with applications ranging from milling, solder paste

dispensing, and silk screening. For this project, a spindle mount was designed and prototyped. In

addition, a solder paste dispensing tool attachment was designed for future prototyping and testing.

3.4.1 Spindle Mount

The weight of a 10lb spindle was accounted for in the design of the machine, allowing for

significant millwork to be done by this CNC. However, for the prototype a low cost, light duty spindle

was fitted to the z-axis. The components of this spindle mount are presented in the following drawings:

B-33, B-34, B-35.

3.4.2 Solder Paste Dispenser

Considerable design was done to create a method of dispensing solder paste from a syringe using

a small stepper motor, a reciprocating screw, and a plunger. These components are presented in

drawing numbers B-36, B-37, B-38, B-39, B-40, B-41, and B-42, and the assembly is shown in Figure

5.2-1. It was determined that the paste flowrate was related to the motor speed using Equation 5.3.1,

which would be used in the control algorithm for the paste dispenser. Also, the required torque was

found to be dependent on the fluid pressure as shown by equation 5.3.2.


22

Figure 3.4-1

(5.3.1)

(5.3.2)

An attempt was made to model the paste flow as a newtonian fluid using the general

engineering equation, shown in Equation 5.3.3, with head losses along each length of the syringe, at

each diameter contraction, and at the needle exit. These calculations are shown in appendix Table 5.2-1

with the conditions at each point in the syringe shown in Table 5.3-1. Also, hand calculations and a

sketch of the paste syringe with the locations numbered are shown on page 48 of Pat Brokaw’s design

notebook. However, due to the minimal needle size and the low flowrate it appeared that some

modifications must be made to this equation. A simplified attempt was made using only the dynamic

pressure of the fluid and the head loss along the length of the needle, as shown in Equation 5.3.4. Still,

the resulting pressure appeared to exceed what was determined to be a reasonable by those familiar

with the use of a paste syringe. In a final attempt to spec the motor, forces applied to syringe plunger

were approximated and converted to the required torque in Table 5.4-1. From this, it was determined

that a small stepper motor would be sufficient to power the reciprocating screw and plunger and further

analysis would require prototyping and testing.

(5.3.3)

(5.3.4)

3.5 Machine Electronics Additional design considerations to accommodate the electronics required for the operation of the

CNC machine. This includes the wiring to the motors, the housing for the main controller and driver

boards, and the case for the pendant to be use by the operator to make machine inputs.


23

3.5.1 Cable Carrier

Cable carriers were used to organize the wiring to the motors, spindle, and limit switches and

allow them to move with the machine throughout its travel. Appendix Table 4.1-1 provides a list of the

wires to be held in the wire carrier for each axis. The diameters of each wire were measured and cable

carriers of appropriate dimension were ordered from the McMaster Carr website.

3.5.2 Electrical Component Housing

A protective case was required to house the main controller board, the motor driver board, a

capacitor, a relay, and a transformer. Polycarbonate was selected for the case material to provide

protection while allowing the electronics to be attractively displayed. In this case, the main controller

board was placed on the bottom while the driver board was elevated directly above. A divider was then

placed inside the case to separate these boards from the capacitor, relay, and transformer. The purpose

of this divider was to protect the boards in the event of a catastrophic capacitor failure. Additional

accommodations were made to allow for connections to the motors and the spindle, as well as VGA, DB,

Ethernet, USB, DC power, and AC power inputs/outputs. The drawing of this housing has been

presented in the assembly drawing BB-5.

3.5.3 Pendant Case

The pendant will allow the machine operator to make positional and feed rate adjustments as

well as perform other input tasks as described in the pendant subsystem. A case was designed to house

the two separate boards containing functional and directional buttons and the OLED screen. The

drawing for this case has been labeled B-43. An attempt was made to machine this complex design from

high density polyethylene. However, it was determined that some dimensions needed to be changed to

improve the strength of the casing if this material was to be used. Further considerations were made to

utilize polycarbonate for this construction of this case to provide greater strength and allow the internal

boards to be displayed. For prototyping purposes, the pendant boards will be mounted to single piece of

polycarbonate and further machining will be done to finish this component.

3.6 Equipment Lists

3.6.1 Design Tools

AutoCad Inventor

Microsoft Excel

3.6.2 Machining and Assembly Tools

Mill

Lathe

Grinding Lathe

Horizontal and Vertical Bandsaws

Drill Press

Chop Saw


24

Cordless Drill

Combination Wrenches

Allen Wrenches

Screw drivers, both Phillips and Flat head

Various endmills from 1/8-5/8

Fly cutter and various milling tool heads

Boring head

Calipers

Micrometers

Telescoping gauges

Depth gauges

Tap handle

Taps: #4-40, #6-32, #8-32, #10-24, 1/4-20, 3/8-16, 3/8-24, 1/8-27 NPT

Die: 5/16-18

Drill bits: #43, #36, #32, #29, #27, #25, #24, #18, #9, #7, F, H, Q, W, X, 5/16”, ½”,

3.7 Components and Specifications

3.7.1 Material Specifications

Material E (106psi) Sy (ksi) ρ (g/cm3) E/ρ Sy/ρ Hardness

Steel A36 29 36 7.85 3.69 4.6

Aluminum 6061-T6 10 37 2.71 3.69 13.7

HDPE 0.12 4.3 0.96 0.13 4.5 D60-70

Polycarbonate 0.32 9 1.2 0.27 7.5 M70-82

3.8 Components

3.8.1 Z-axis

The z-axis allows vertical motion of the tool head. The total travel of the vertical axis on this CNC

machine is 8.24 in. An assembly of the z-axis is shown Figure 8.2-1 and in the drawing BB-1. The

following components are included:


25

Figure 3.8-1

Z-axis Ballscrew: A 5/8 in ballscrew was used and shaft steps were machined to allow for

thrust and ball bearing supports. The dimensions of the ballscrew are shown in drawing B-1

and the specifications, per Roton, are included in the Section 9 of the appendix.

Z-axis Thrust Bearing Block: The design of this component required minimizing its height in

order to reduce the overall height of the z-axis. This part drawing is B-2.

Z-axis Ballnut Flange: This part has internal threads for the ballnut and threaded holes for

mounting to the z-mount as shown in part drawing B-3.

Z-top: A recessed section allows for the z-axis motor, and the ball bearing supporting the

ballscrew was pressed into the z-top. Part dimensions are shown in drawing B-4.

Z-bottom: The bottom of z-axis allows for the mounting of the thrust bearing block and

clearance of the end of the ballscrew. Refer to drawing B-5 for dimensions.

Z-sides: These parts provide additional strength to the z-top and z-bottom which must

withstand the thrust force of the ballscrew. These parts are shown in drawing B-6.

Z-Back: The z-back acts as the base component in the z-axis. The z-top, z-bottom, z-sides,

and the versa rails all mount to this component. The z-back was also used to mount the z-

axis to the x-traveling block. This part was designed with grooves for aligning the versa rails

and an inset in the top to position the z-top. The dimensions of this component are shown

in drawing B-7.

Z-mount: This part connects the tool head, the versa blocks, and the ballscrew. Drawing B-8

shows the dimensions of this part.

Standoffs: These were included to account for height difference between the versa blocks

and the clearance required for the ballscrew and its supporting bearings. Clearance holes


26

were machined for the versa block bolts and the threaded holes are used to mount the tool

head. These part is shown is shown in drawing B-9.

Versa rail: These precision rails were used to guide the vertical travel of the tool head and

were selected over other alternatives in order to reduce the height of the z-axis. The

dimensions are shown in drawing B-10 and the specifications, from Anaheim Automation,

are given in Section 9 of the appendix.

Versa block: These travel along the versa rail and use ball bearings to support a maximum

dynamic load of 2449 lbs. The specifications from Anaheim Automation are provided in

Section 9 of the appendix and the part drawing is B-11.

3.8.2 X-axis

The x-axis provides tool head motion across the work table with a maximum travel of 24.15 in. The

assembled x-axis, shown in Figure 8.2-2 and in drawing BB-2, includes the following components:

Figure 3.8-2

X-axis Ballscrew: A 5/8 in ballscrew as used to provide linear motion along the x-axis and the

dimensions of this part are given in drawing B-12.

X-axis Thrust Bearing Block: The part holds the thrust bearings required to carry the linear force

of the ballscrew. Dimensions are shown in drawing B-13.

X-axis Ballnut flange: This part connects the ballnut to the the x-traveling block and transmits

the motion of the ballscrew. This part is shown in drawing B-14.

X-Rods: These rails guide the precise linear motion of the x-axis while supporting the weight of

the z-axis and withstanding the force due to the cutting head. Dimensions are found in

drawing B-15 and Lintech Motion specifications are included in Section 9 of the appendix.


27

X-Traveling Block: This part holds the ball bushings that slide along the x-rods. These bushings

have been pressed into the bored holes for an interference fit that will hold throughout the

operating temperature range. The x-traveling block also provides mounting holes for the z-axis

and all dimensions are shown in drawing B-16.

X-Bushings: The bushings allow the x-traveling to travel along the x-rods and carry the load

through ball bearings. The specifications of these bearings from Lintech Motion are provided in

Section 9 of the appendix.

X-Top: This part mounts across the top of the x-axis and provides some additional strength as

well as providing for the mounting of the x-axis cable carrier. The part dimensions are shown in

drawing B-17.

X-Back: This part covers the back of the x-rails, providing some strength but primarily protecting

the rails from debris. Drawing B-18 shows the dimensions of this component.

3.8.3 Base

This assembly provides the solid foundation for the CNC machine as well as support for the y-axis.

The assembly, shown in Figure 8.2-3 and in drawing BB-3, includes the following components:

Figure 3.8-3

Table Bottom: The table bottom is the base of the machine and has two 36 in, aluminum

extruded rectangular tubes mounted beneath it that provide a solid stand for the machine. The

bottom also has channels for the precise placement of the y-axis linear guide rails. This part is

shown in drawing B-19.

Table Ends: The table has two end components to which the y-axis ballscrew and the y-axis

drive motor mount. One end, the Table End-motor shown in drawing B-20, supports the


28

ballscrew through a ball bearing and has a recess for the motor mount. The other, Table End

shown in drawing B-21, provides mounting holes for the z-axis thrust bearing block.

Table Sides: The table sides add strength to the table ends which experience the thrust force of

the ball screw while also protecting against debris from accumulating under the work table.

The dimensions of these parts are shown in drawing B-22.

Work Table: The work table, shown in drawing B-23, mounts across the table ends and

provides 1160.25 in2 of area on which to mount the part to be machined. In order to support

weight of the part, support rails were mounted beneath the work table to remove the

deflections.

3.8.4 Y-axis

The y-axis provides 31 in of travel along the length of the work table. This assembly is shown in

Figure 8.2.4 and drawing BB-4. The following components comprise the y-axis:

Figure 3.8-4

Y-axis Ballscrew: Linear motion is provided by a 5/8 in ballscrew and is dimensioned in

drawing B-24.

Y-axis Thrust Bearing Block: The thrust bearings that carry the linear force of the ballscrew

have been pressed into the thrust bearing block. This part is identical to the x-axis thrust


29

bearing block, and the dimensions of this block as well as the bearing bores are shown in

drawing B-13.

Y-axis Ballnut Flange: This part connects to the y-cross component and transmits motion

from the ballscrew to the y-axis. It has been dimensioned in drawing B-25.

Y-Rails: Supported guide rails were selected for the y-axis due to the weight that had to be

supported and the length over which this load had to be supported. Dimensions of these

rails are shown in drawing B-26 and the specifications from Lintech Motion have been

included in Section 9 of the appendix.

Y-axis Bushing Blocks: Assembled bushing blocks were ordered from Lintech Motion for the

y-axis. These use ball bearings to carry the load and to provide precise motion. These have

been dimensioned in drawing B-27 and the specifications have been included in Section 9 of

the appendix.

Y-Lifts: These parts mount to the y-axis bushing blocks and contain mounting holes for the

vertical gantry sides. These were designed to offset the y-rails further under the table,

protecting them from debris which could damage the rail surface or the bushings. The y-lifts

also position the vertical gantry sides such that the center of gravity is centered on the

bushing blocks to prevent uneven wear. The dimensions of these parts are shown in

drawing B-28.

Y-Cross: The y-cross spans the width of the y-axis and connects the y-lifts and y-axis bushing

blocks which travel along each rail. The ballscrew flange connects to the center of the

y-cross, transmitting motion of the ballnut to the y gantry. The dimensions of this part are

shown in drawing B-29.

Y-axis Vertical Gantry Sides: The vertical gantry sides mount to the y-lifts at the bottom and

act as the ends of the x-axis at the top. The x-rods, x-axis ballscrew, x-back, and x-top all

mount between the vertical gantry sides at the top. One vertical gantry side, shown in

drawing B-30, has a mount for the x-axis drive motor and supports the ballscrew using a ball

bearing. While the other, shown in drawing B-31, allows for mounting of the x-axis thrust

bearing block.

Y-Gantry Insert: Inserts were made for the gantry to insure correct positioning of the x-rods

over time. A continued load can lead to creep in the HDPE gantry sides. In order to prevent

future misalignment, aluminum inserts, shown in drawing B-32, were machined with x-rod

positioning holes made to match those in the gantry sides.

3.8.5 Tool Heads

The exchangeable tool heads allow for a multifunctional CNC. The tool heads that have been

designed for this machine include a spindle and a solder paste dispenser.

3.8.5.1 Spindle

The spindle will allow the CNC to mill and engrave. The parts included in this tool head include:


30

Spindle Plate: The spindle plate has holes for mounting to the z-axis as well as holes for

mounting the spindle. Dimensions of this plate are shown in drawing B-33.

Spindle Holder: The holder has been bored to the outer diameter of the spindle and

clearance holes have been machined for mounting to the spindle plate. The dimensions of

this part are shown in drawing B-34.

Spindle: The spindle used for this prototype has been dimensioned in drawing B-35.

3.8.5.2 Solder Paste Dispenser

The solder paste dispenser will dispense solder paste onto a printed circuit board using a syringe and

the plunger system shown in Figure 8.2-5. The individual components included in this tool head include:

Figure 3.8-5

Plate: This plate mounts to the z-axis while containing holes for the dispenser motor and the

syringe to mount. Also a groove to guide the plunger was designed into the plate. This is shown

in drawing B-36.

Motor Mount: This mounts the driving motor to the plate and is shown in drawing B-37.

Syringe Mount: This holds the syringe in position and mounts it to the plate. It is shown in

drawing B-38.

Syringe: The solder paste is sold in and dispensed from a standard size syringe from Amtech.

Screw: A reciprocating screw will extend the plunger into the syringe. This screw is shown in

drawing B-39 and will provide a 3 in stroke.

Paste Dispenser: This part has internal threads that will allow it to extend as the screw is rotated

and will be guided linearly by the groove in the plate. This part has been dimensioned in

drawing B-40.

Plunger: The plunger screws into the end of the paste dispenser and will contact the plunger

inside of the syringe. This part, which is shown in drawing number B-41, was designed to be

interchangeable in the event that a different sized syringe was used.


31

Coupler: The couple, shown in drawing B-42, will connect the screw to the motor shaft.

3.8.6 Machine Electronics

Some mechanical components were necessary to account for the machine electronics. These items

include:

Pendant Case: The pendant allows the operator to make inputs to the machine. A case was

designed to house the circuit boards and screen for this component. The dimensions of the

pendant case are shown in drawing B-43.

Electrical Component Housing: A case was designed to house and protect the main controller

board, the motor driver board, a capacitor, a relay, and a transformer. Drawing BB-5 shows the

assembly of the component housing and Table are showing in the drawing BB-5.

Cable Carriers: Cable carriers were ordered from McMaster Carr to hold the wiring to the

motors, limit switches, and the spindle. Information about the sizes and lengths of these cable

carriers are given in appendix Table 4.1-1.

3.8.7 Additional Components

Some additional components that were either necessary for the assembly of the machine or

common for each of the three axes include:

Ball Bearings: Ball bearings were used to support one end of the ballscrews. Specifications for

these bearing are given in Section 9 of the appendix.

Thrust Bearings: Thrust bearings were used in the thrust bearing block assembles to account for

the linear force of the ballscrew and to remove linear play in the ballscrew position. The

specifications for these bearing are given in Section 9 of the appendix.

Bearing Seals: Seals were used to seal the thrust bearing blocks to allow them to be filled with

grease in order to lubricate the bearings. Specifications for these seal are given in Section 9 of

the appendix.

Seal Retainer: The seals that fit the ballscrew shaft diameter had an outside diameter that was

smaller than that of the thrust bearings. Seal retainers were machined with an outside diameter

of 0.875 in and an inside diameter of 0.625 in as shown in drawing B-44. The seals were pressed

into the seal retainers which were then pressed into the thrust bearing blocks.

Pulleys: Timing belt pulleys were used on both the ballscrew shafts and the motor shafts to

transfer the torque. Specifications for these pulleys are provided in Section 9 of the appendix.

Belts: Timing belts were used to transfer torque from the motors to the ballscrew. The lengths

and specifications for these belts are given in Section 9 of the appendix.

Motors: Stepper motors were used to power the ballscrews. A 166 oz.in motor was used for the

z-axis and a 276 oz.in motor was used for both the x-axis and z-axis. Additional specifications are

given in Section 9 of the appendix.

Fasteners, Set Screws, and Washers, Board Standoffs, and Grease Zerks: A complete list of

sizes and totals can be found in the appendix Table 7.2-1 and 7.2-3.


32

3.9 Data Sources

3.9.1 Websites

Roton, http://www.roton.com

Lintech, http://www.lintechmotion.com

Anaheim Automation, http://www.anaheimautomation.com

VXB, http://www.vxb.com

MCMaster Carr, http://www.mcmaster.com

Online Metals, http://www.onlinemetals.com

Norva Plastics, http://www.norvaplastics.com

MSC Direct, http://www.mscdirect.com

Fastenal, http://www.fastenal.com

Machine Shop Discount Supply, http://www.msdiscount.com

Grainger, http://www.grainger.com

Amazon, http://www.amazon.com

Newegg, http://www.newegg.com

3.10 Fault analysis Fault analysis of this CNC machine concludes that failure will occur if the machine ceases to

operate, due to a failed fastener or component, or if the machine begins to operate out of tolerance due

to excessive wear.

3.10.1 Fastener and Component Failures

The ballscrew must transfer motion through the ballnut flange to each axis. The most likely

fastener failure will occur in the bolts that hold the ballnut flanges to the y-axis and the z-axis. Possible

component failure could occur in the ballnut flanges or to the gantry components that directly

experience the thrust force of the ballscrew. These gantry components include the table ends and the

top and bottom of the z-axis. These components may not fail completely. However, fatigue may

eventually allow excessive deflections that will cause the machine to operate out of tolerance.

Design modifications could be made to increase fastener or component size in order minimize the

risk of failure. In addition, reinforcement could be added to the gantry components to reduce the effect

of fatigue. Despite adding complexity to the design, the cost of these modifications would not be

significant as slightly larger aluminum stock or additional reinforcing components only reflect a minimal

increase in expense.

3.10.2 Excessive Wear

Excessive wear on crucial components will cause the machine to lose tolerances and the

usefulness of the CNC machine will become limited to low precision work. If wear is extreme, the

usefulness of the machine will be completely lost or the machine may become inoperable.


33

Key components are found in the drive and the guidance systems. The drive system consists of

the ballscrew, the ballnut, and the supporting bearings. If wear is experienced by the bearings,

movement of the ballscrew will be allowed. If the ball bearings inside of the ballnut are worn, the

ballscrew will be unable to accurately transmit linear motion. Most likely the ballnut will experience

wear first, but soon after wear on the ballscrew itself will occur. The linear guide system consists of the

guide rails and the ball bushings for each axis. Wear may be experienced by the ball bearings inside each

bushing or to the shafts themselves. If any of these components wear excessively, the machine will be

unable to position the tool head with the desired precision.

Design modifications cannot provide a solution to these modes of failure. All of the drive and

guide system components have been selected for use within their stated specifications. Therefore, only

proper and routine lubrication can prevent this wear and extend the life of the machine. The bushings

and bearings are to be greased and the shafts are to be oiled as per the User’s Manual. If these actions

are taken, the risk of failure due to excessive wear will be minimal.

3.11 Health & Safety, Environmental, Life Cycle, and Societal Issues When operating the CNC machine, the ballscrews can emit significant noise. Continual exposure to

this environment can lead to hearing loss. Proper ear protection should be worn. Other components

that can cause injury include the tool heads, belts, and ballscrews. Contact with these rotating

components must be avoided.

Waste products from machine include lubrication grease and metal shavings from machining. These

by-products should be disposed of properly. If a component on the machine requires replacement,

whether the part is machined from HDPE, aluminum, or steel, these components should also be

disposed of in a manner that is not harmful the environment or other individuals.

3.12 Engineering Drawings All engineering drawings have been included in Section 10 of the appendix, with the exception of

the components that require reference to manufacturer data sheets. These are included in Section 9 of

the appendix.


34

4. Electrical

4.1 Motor Driver Board

4.1.1 Scope

The following section provides a detailed technical description of the function of the Motor

Driver. Most component values were derived from the specifications of Data Sheets. Test,

measurement, and fault analysis is included and provides detailed accounts of all tests performed

with measurement and fault analysis of each circuit. Health and safety pertaining to the Motor

Driver is also including in this section. Equipment list, test data and simulations are also in

Appendix C. See Users Manual for complete list of specifications.

4.1.2 Block Diagram

The Motor Driver provides a Low Voltage Power Supply which generates four voltages levels 5,

+12, -12, and 24 Vdc. The 5Vdc Supply provides the power to the Optical Isolation and Micro-

stepping Sequencer. Step, Direction, Enable, Reset, MS1, and MS2 are all Optical Isolated

inputs from the Main Controller. The Step input signal steps the motor. The Direction input

changes the direction of the motor. The MS1 and MS2 inputs set the micro-stepping mode

which is either full, half, ¼ or 1/16 step mode. The Voltage Reference (Vref) determines the

maximum current through the motors and there are 3 independent Voltage References for each

axis. The Motor Power Supply provides the power to the motors. The Micro-stepping

Sequencer controls the Mosfet H-Bridge which drives the motors. The Motor Driver Board

provides three fuse blown LED Indicators and a 5V indicator which is lit during normal

operation. The Driver Board Ready, Vbb Ready, and Fault signal are outputs to the Main

Controller and provide status information of the Motor Driver Board.


35

Vbb Ready

Optical

Isolation

Step

Direction

Enable

Reset

Micro stepping

Sequencer

MOSFET

H-Bridge

A+

A-

B-

B+

Block Diagram

Motor Driver Board

Logic Inputs

From Controller

PFD1, PFD2, SR

(jumper selectable Connections to Bipolar

Stepper Motors

X,Y,Z axis

Vm+

Vm-

Motor Power

Supply

MS1, MS2

12 V

Fuse

Blown

-12 V

Fuse

Blown

24 V

Fuse

Blown

5 V

GOOD

Driver Board

Ready

Driver Board

Fault

To

Controller

LED Indicators

Output Signals

Vref

X,Y,Z axis

+5 Vdc

+-12 Vdc

Low Voltage

Power Supply

System Monitoring and

Fault Identification

24 Vdc To Controller


36

4.1.3 Technical Description

4.1.3.1 Input Optical Isolation

The drive board provides high speed optical couplers for each STEP and DIRECTION input

signal and provides low speed optical isolation for ENABLE, RESET, MS1, and MS2 input

signals. Each input signal comes from the controller.

Optical Isolation is required to isolate the driver board from the controller to avoid damaging it

from high frequency noise and voltage spikes occurring on the driver board.

This is the main interface between the Motor Drive Board and the Main Controller Board.

4.1.3.1.1 High speed optical couplers

The high speed optical couplers (U8, U9, U14, U15, U20 and U21) are required because of the

high frequency at which the motors will be stepped. The response of the Optical coupler is

crucial to the performance of the system.

R24, R25, R44, R45, R56 and R57 are input resistors each of the couplers and provide 2.3 mA

to drive them into saturation when the 3.3 V input signal from the microcontroller is sent.

Resistor values were based on specifications is in the data sheet and equations derived in

Appendix C.

See Micro-stepping Sequencer Schematic C-1

See Data Sheet for SFH6720T High Speed Opto-Coupler in Appendix C for a complete

functional description and specifications.

4.1.3.1.2 Optical Isolators

The Low speed Optical Isolator (U10) provides the same isolation function as the High Speed

optical couplers but do not require an excellent frequency response. These signals will only

enable or disable certain functions and are considered constant.

R16, R17, R18, and R19 are the input resistors of each input to the Optical Isolator and provide

2.2 mA to drive them into saturation when a 3.3 V input signal from the microcontroller is sent.

The output resistors R20, R21, R22, and R23 are pull-down resistors. The isolators are designed

to function as inverters to prevent the A3986 from being enabled at power up. This prevents any

unwanted movement of the CNC during this time.


Appendix C.



37

See Data Sheet for SFH6720T High Speed Opto-Coupler in Appendix C for a complete


4.1.3.2 Low Voltage Power Supply

The low voltage Power Supply provides four voltage levels, +5, +-12 and +24 Vdc. The +5 volts

is used to power all the circuitry on the board expect the operational amplifiers, which uses +-12

volts. The +24 volts is used to operate two solid state relays.

4.1.3.2.1 Input Power Conditioning

Consists of Terminal Block 1 (TB1), step down transformer (XR1), full bridge rectifier (BR2),

and filter capacitors (C17, C18, C19, and C20). TB1 provides AC main connections and can be

configured for 120/240 VAC. See Users Manual for 120/240 VAC terminal block

configurations. The Transformer provides the required step down voltage to the Full Bridge

Rectifier (BR2). The Rectifier and filter Capacitors provide the DC input voltage to the

regulators (VREG2, VREG4, and VREG3).

See Low Voltage Power Supply on Schematic C-2.

See Data Sheet for MB110S-TPMSCT-ND Bridge Rectifier in Appendix C for a complete

functional description and specifications

4.1.3.2.2 +-12Vdc Supply

The +-12 Vdc (VREG2, VREG4) is the regulated input to the +5Vdc regulator and provides the

supply voltage for the Voltage Reference Circuitry.

The output voltage of VREG2 and VREG4 are fixed by resistors (R12, R13 and R29, R30

respectively) .These supplies are designed to provide increased ripple rejection by connecting a

capacitor to the adjustment pin (pin-1) of VREG2 and VREG4. These bypass capacitors (C10

and C14) prevent ripple from being amplified as voltage on the output is increased.

The supply also has input and output short circuit protection. The diodes prevent current from

entering the regulator. When the input of the regulator is shorted the output capacitor (C6 and

C8) would normally discharge into the output of the regulator. This will not haven because

discharge current will be shunted to the input side of the regulator by diodes (D5 and D1)

respectfully. To prevent the bypass capacitors from also discharging into the regulator, diodes

(D2 and D6) are used provide a low resistance path back to the output side of the regulator.


Appendix C.



38

See Data Sheet for LM317 and LM377 3-Terminal Adjustable Regulator in Appendix C for a

complete functional description and specifications.

4.1.3.2.3 Slow Turn on Circuit

Each supply also has a slow turn on Circuit. The +12 Vdc slow turn on circuit consists of P-

channel mosfet (U32), capacitor (C75), resistor (R63) and diode (D8). The voltage at the gate

and source of U32 slowly rise until the capacitor is fully charged to 12 volts at which time the

gate voltages becomes more positive then source voltage an U32 gets turned off; effectively

removed from the system.

The -12 Vdc supply has the same slow turn on circuit as the +12Vdc supply and consists of N-

channel mosfet (U33), R64, C76, and D9.


4.1.3.2.4 5Vdc Supply

The 5Vdc supply (VREG1) powers the optical couplers, optical isolators, jumper selectable

functions, the A3986 Micro-stepping sequencer, and the Vbb Protection Circuit. The 5Vdc

supply has been designed to deliver up to 185 mA at 20 degrees Celsius. It provides temperature

protection shut down at temperatures greater than 150 degrees Celsius. C16 and C9 provide

stability to VREG1.

Selection of input voltage was based on equations from the data sheet and Matlab graphs in

Appendix C. C16 and C19 were selected from specifications from the data sheet in Appendix C.

The 5 volt supply has also been designed with short circuit protection (D7). The turn on time for

the 5Vdc supply is approximately 15 seconds, which is set by the slow turn on circuit for the +12

Vdc supply. The 5Vdc supply has an indicator light which illuminates when 5V is present.


See Data Sheet for TDA3664 Very Low Dropout Voltage Regulator in Appendix C for a

complete functional description and specifications.


39

4.1.3.2.5 24 Vdc Supply

The 24 Vdc supply (VREG3) is used to power the chassis mounted solid state relay which turns

on AC power to the motor driver board and the motor power supply. Another relay is used to

apply AC power to the spindle head.

Note: The main controller operators these relays.


See Data Sheet for LM317 3-Terminal Adjustable Regulator in Appendix C for a complete


4.1.3.3 Motor Power Supply

The motor supply provides the power to drive the motors on the CNC. The motor supply can

provide an unregulated output of 40 Vdc at full load. The supply consists of a toroidal

transformer, filter capacitors, and a bridge rectifier (BR1). The Transformer and filter capacitors

are chassis mounted. C74, C72, C87, C86 are located on the Motor Driver Board and provide

filtering of high frequency noise and reduce transient voltage spikes during normal operation.

Transient voltage suppressor (TVS1) is used to prevent transient voltage spikes over 55 V.

Voltage spikes in excess of 55 Volts may destroy the A3986 therefore a transient voltage

suppressor has been installed to prevent this from occurring. See Motor Power Supply

Simulation Data in Appendix C.

A toroidal Transformer was used in the design of the motor power supply for several reasons.

First, the size of the toroid is about half the size of standard power transformers. Since the

transformer will fit into a smaller space; this allows the enclosure to be smaller, which reduces

the material cost of the system. Second, the toroid produces very little transformer humming so

noise pollution produced from the system will be reduced. Also, toroid transformers produce

nearly no stray magnetic fields which reduce electromagnetic interference on other circuit

components in the electrical cabinet.

See Motor Power Supply on Schematic C-3

4.1.3.4 Micro-stepping Sequencer with External H-Bridge

The A3986 is the heart of the driver board. It is micro-stepping driver with a minimum number

of control inputs. It is capable of operating 2-phase bipolar stepper motors in full, half, quarter

and sixteenth step modes. The current in motor is controlled by a fixed off-time pulse width


40

modulation control circuit. The current in the motor at each step is set by the value of an external

current sense resistor, a reference voltage, and the output of the DAC controlled by the translator.

The A3986 provides all the necessary circuits to ensure that the gate to source voltage of both

high side and low side mosfets are above 10 V, and that there is no cross conduction in the motor

windings. (1)

The use of pulse width modulation provides the cost-effective solution for designing high

efficiency motor driver. By utilizing PWM, the size of the motor supply is greatly reduced

because the current required from the supply will be a fraction of that in the motor windings.

Also, there no need to design a complex controller because motor stepping is controlled by two

inputs. (Step and Direction)

See Data Sheet for A3986 Dual Full-Bridge MOSFET Driver with Micro-stepping Translator in

Appendix C for a complete functional description and specifications.

4.1.3.4.1 Axis Control

The following describes the X-axis control. The A3986 (U1) provides all the circuitry to control

a 2-phase bipolar stepper motor using two external N-channel H-bridges. U2 and U3 makeup the

A-phase bridge while U6 and U7 makeup the B-phase bridge. The maximum current through

each phase of the motor is controlled by current sense resistors R9 and R11 respectively.

Capacitors C2, 3, 4, 5 provide the increased gate voltage needed to turn on the high side N-

channel mosfets. Capacitors C1, C31 and C32 provide stability during transient conditions

which exist when the motors are stepping. R1 through R8 are external gate resistors to the

mosfets and control the rate of change of the voltage and current in the motor terminals. R10 is

the oscillator timing resistor.

Capacitor values were selected from specifications in the A3986 data sheet. R10’s component

values were based off equations from the A3986 data sheet.

Note: Y and Z-axis control is identical to the X-axis control.


See Data Sheet for A3986 Dual Full-Bridge MOSFET Driver with Micro-stepping Translator in

Appendix C for component value selections or formulas.


41

4.1.4

4.1.4.1.1 H-bridge

The selection of the external H-bridge was crucial to the over performance of the system.

IRF7341PbF dual HEXFET power mosfets were used because of the low resistance from source

to drain when turned on (Rdson) and power dissipation of 0 watts. The maximum power

dissipated by the mosfets will only be .235 watts when using 4.7 amp motors. This also limits

heating of surrounding components increasing performance.

The by limiting the current to a maximum of 4.7 amps no heat sink will be required and the full

capabilities of the mosfets will be utilized increasing system performance. Also, utilizing dual

surface mount mosfets the space required to house them is greatly reduced compared to other

systems on the market.


See Data Sheet for IRF7341PbF HEXFET Power MOSFET in Appendix C for a complete


4.1.4.1.2 Current Sense Resistors

The feedback resistors were also choosing to reduce power dissipation and heating affects on

other system components. By selecting .043 ohm resistors surface mount packages could be

utilized, reducing the need for large high watt resistors. A maximum power dissipation of .202

watts is required compared to 2.35 watts when choosing a .5 ohm resistor.

Although selecting .043 ohm will reduce heat and component size the trace resistance becomes

an issue and will adversely affect the accuracy of the current feedback loop. By choosing this

option the PCB layout of the current sense resistors became critical to the performance of the

system and the solution is fully discussed in the PCB layout section.


4.1.4.2 Voltage Reference Circuits

There are 3 independent voltage reference circuits that set the maximum and minimum current

through each motor. It consists of a voltage divider and an operational amplifier which provides

a stable reference between .688 and 1.6168 Vdc, which corresponds to a current adjustment of 2

to 4.7 A. The maximum current limit is set to protect the H-bridge mosfets from being destroyed

by improper adjustment.


42

4.1.4.2.1 X-Axis voltage Reference Circuit

The voltage divider comprises of resistors (R31, R32), variable resistors (VR1, VR3), and C37.

R31 and R32 set the maximum and minimum voltages, respectively. VR1 and VR3 provide the

fine and coarse voltage adjustment respectively. C37 stabilizes the input to the operational

amplifier. Decoupling capacitors C38 through C40 provide additional high frequency noise

reduction. The amplifier U23 is design for unity gain feedback. The output of the amplifier has

a test point for easy adjustment of the voltage reference.

Note: The Y and Z-axis voltage reference circuits are identical to the X-axis.

Resistor values were based from equations derived in Appendix C.

See Voltage Reference Schematic C-4

See Data Sheet for OP27G Operational Amplifier in Appendix C for a complete functional

description and specifications.

4.1.4.3 System Monitoring

The motor driver provides four on board indicators and three outputs that provide information to

the controller on the status of the driver board.

4.1.4.3.1 Fuse Blown Indicators

Three fuse blown indicators will light up if there is a fuse blown on the +-12 Vdc, and 24 Vdc

regulators. This provides the user and maintenance personal a way to quickly diagnose there is

fuse blown to bring the system back up quickly, effectively reducing down time.

The +12 Vdc fuse blown indicator consists of P-channel mosfet (U30), resistor (R59), diode

(D10), and light emitting diode (LED2). The -12 Vdc fuse blown indicator consists of N-

channel mosfet (U30), R61, D12 and LED1. The 24Vdc fuse blown indicator consists of P-

channel mosfet (U31), R60, R62, D11, and LED3.

Resistor values were selected from equations derived in Appendix C. Simulations for all fuse

blown indicators were performed using Multisim and worked as designed. See Appendix C for

Simulation.



43

4.1.4.3.1.1 5 Vdc Indicator

The driver also provides an indicator light that lets the user know that +5Volts dc is present and

that the driver board is functional.

The indicator consists of R74 and LED4.


4.1.4.3.1.2 Vbb Protection Circuit

The Vbb Protection Circuit provides protection in the event of an over current condition. The

circuit is designed to trip when an over current condition (>65 mA) occurs. The circuit was

implemented to take advantage of the under voltage protection inherent to the A3986 chip. By

cutting off Vbb to the chips they would automatically disable themselves preventing any damage

from occurring to the A3986 chips.

The circuit comprises of U38, U39, and R85, 73, 80 and C88. When an over current condition

exists the voltage drop across R80 is greater than 65 mV the gate voltage on the NPN mosfet

(U38) will drop to 0V turning off U38 until the over current condition is removed. The

decoupling capacitor C88 provides stability during transient conditions.

R80’s component value was selected from equations in the LT1910 data sheet.

See Data Sheet for LT1910 Protected High Side MOSFET Driver in Appendix C for a complete



4.1.4.4 Driver Outputs to Controller

These circuits are designed to be used with any miscellaneous inputs to the controller board that

uses an optical isolator. They provide the current to drive an optical isolator in either the linear

or saturation region to allow the controller to monitor the voltage on the output of the isolator.

All component values for the Driver Outputs were selected from equations derived in Appendix

C.

4.1.4.4.1 Driver Ready Signal

The Driver Ready Signal is designed to let the controller know when the driver board circuitry is

powered up and ready to use. When the driver boards +12 Vdc is completely charged it provides

a nominal 533 uA to drive the input of an optical isolator in the linear region. The circuit

comprises of resistor (R72) and jack (J10).


44

See Low Voltage Power Supply Schematic C-2.

4.1.4.4.2 Vbb Ready Signal

The Vbb Ready Signal is designed to let the controller know that the motor voltage is full

charged and ready to drive the motor. When the motor voltage is fully charged it provides a

nominal 533uA to drive the optical isolator in the linear region. The circuit comprises of R69,

R70, R71 and J9.

See Motor Power Supply Schematic C-3

4.1.4.4.3 Fault Signal

The Fault Signal is design to let the controller know that there is a fault in system. The circuit

comprises of AND gate (U40), R81, and J11. When a fault is detected the output of U40 will go

low (0V) and cutoff the optical isolator.

See Motor Power Supply Schematic C-3

4.1.4.5 PCB Layout

The PCB Layout was crucial in the implementation of the Motor Driver.

4.1.5 Health and Safety

Noise Pollution from the motors may cause a loss of hearing if exposed to for long periods of

time. Anyone who will be operating the equipment and is in close proximately to the motors

should wear hearing protection.

Supply Voltages of 45 Volts are present on the driver board. Use caution when performing

adjustments when power is applied. Never perform adjustments without the presence of a person

that can perform CPR. Also, when power is turned off voltages above 45 volts may still exist.

Allow time for filter capacitors to discharge or use a shorting probe to short the voltage to

ground. Installed on this equipment is a LED indicator across the filter capacitor mounted to the

chassis. This indicator lets maintenance personnel know there is voltage still present of the

capacitor.

Components used in production of the driver board may or may not contain hazardous material.

Disposal of all electronic material should be in accordance with the guidelines set by the EPA.


45

For information regarding the disposal, handling and recycling of electronic equipment go to

http://www.epa.gov/osw/conserve/materials/ecycling/index.htm

4.1.6 Equipment Required

4.1.6.1 Test Equipment

1. 34401 Agilent multimeter or equivalent standards.

2. Tektronix O-scope

3. DC power supply from 0-30V

4. 33120 Agilent Function Generator or equivalent standard.

4.1.6.2 Soldering Equipment

4.1.7 Schedule Data for Driver Board

Time for Procurement:

1 week from the time of purpose

Time for Installation:

Reflow Oven:

4.1.8 Test, Measurement and Fault Analysis

4.1.8.1 Input Optical Isolation

All optical couplers and isolators are within specified tolerances.

See test data for optical couplers and isolators in Appendix C


See test data for the Low Voltage Power Supply in Appendix C

4.1.8.2.1 +-12Vdc Supply

During testing of the Driver board it was found that the 125mA fast blow fuse for the 12Vdc

supply was being blown because of the inrush current from the circuitry it drives. Procurement

of 125 mA slow blow fuses was not possible in the package required; therefore a slow turn on

circuit was designed to eliminate this issue.

The +-12 Vdc supplies are within specified tolerances.


46

4.1.8.2.2 Slow turn on Circuit

After implementing the slow turn on feature no fuses are being blown. The time it takes the two

supplies to reach +-12 volts is on average of 20 seconds. Since, the +12 V slow turn-on circuit

provides the longest delay time it was used as a feedback signal to the controller called the driver

board ready signal.

During Testing of the slow turn on circuit it was found that the +12 Vdc delay is 25 seconds and

the -12 Vdc delay is 15 seconds. This delay offset could be changed by reducing the value of

R12 or C75. Since, the inrush current problem has been resolved no changes to system will be

made or needed.

4.1.8.2.3 5Vdc Supply

The turn on time for the +5Vdc supply is approximately 16 seconds, which is set by the slow

turn on circuit for the +12 Vdc supply.

4.1.8.2.4 24 Vdc Supply

When conducting the 24Vdc voltage ripple test the measurement was found out tolerance. This

is because the input ripple to VREG4 is higher than the tolerance limits on the regulator and

cannot filter the ripple out. This may have been caused by using old filter capacitors from the

previous circuit board and have been degraded from overheating during unsoldering the

components. The solution to this problem would be to replace the filter capacitors C17 and C18

and retest the ripple voltage. If this does not work then C17 and C18 would be increased to

reduce the input ripple voltage.

Since the 24 Vdc supply is only used to actuate relays, the ripple on it is of no consequence to

the system, and therefore no replacement or resizing of the capacitors are needed.

The voltage measurement test was within tolerance limits.

4.1.9

4.1.9.1.1.1 Motor Power Supply

All other measurements are within specified tolerances.

See test data for the Motor Power Supply in Appendix C

4.1.9.2 Micro-stepping Sequencer with External H-Bridge

During testing it was found that two PCB traces where connected to the wrong side of the H-

Bridge. This caused a catastrophic failure of the A3986 and destroyed most if not all the mosfets

for the H bridge. Also the 5Vdc line was shorted to ground caused by the failure of one A3986.


47

Once the problem was found a corrected a functional test of the driver board was performed and

was successful. Procurement of new A3986 chips was not possible until after March 25 2010

from any supplier. Mark Hopkins a representative from allegro micro that was helping resolve

the issues with the A3986 suggested contacting Dytronics and get free samples. Procurement of

the new chips was possible and the situation was resolved. The PCB Layout was changed to

correct the issue and new PCB’s were ordered.

Mark Hopkins from allegro micro recommended installing 100nF capacitor across the source and

drain of the each mosfet of the H-bridge. The capacitors were not installed on the first PCB

revision 1.0.0. This recommendation was considered and implemented on the new PCB boards.

During testing the performance of the motors was horrible and heating of the mosfets occurred

due of the reactance of the capacitors. They were then removed from the PCB and response of

the motors was excellent and no heating occurred to the mosfets as designed. The Schematic and

PCB Layout were updated and no capacitors form source to drain will be shown.

4.1.9.3 Voltage Reference

All measurements are within specified tolerances.

See test data for the Voltage Reference in Appendix C

4.1.9.3.1 Fuse Blown and 5Vdc Indicators

4.1.9.3.1.1 Fuse Blown Indicators

During Testing of the 24 Vdc fuse blown circuit it was discovered that the wrong PNP mosfet

(U31) was used in the circuit. The drain to source voltage is over the rated voltage of the mosfet

being used and will be shorted out applying a constant current at all times to the LED until the

mosfet breaks down. This failure is of no consequence to the system. The PCB Layout has been

updated with the correct part for future procurement of new PCB’s. The 24 Vdc fuse blown

indicator may be used as an input power indicator light by bypassing U31 if desired.

The +-12Vdc fuse blown indicators work as designed.

See test data for the Fuse Blown Indicators in Appendix C

4.1.9.3.1.2 5Vdc Indicators

The 5 Vdc Indicator works as designed.


All driver output measurements are within specified tolerances.

See test data for the Driver Outputs in Appendix C


48

4.1.9.5 Vbb Protection Circuit

During Testing the Protection Circuit the timing capacitor would not recharge above

approximately 2 V after power on or a fault condition. This should never have unless an over

current condition exists. This condition never existed after startup and the voltage timer circuit

should have charged to 3.5 V.

U39 was assumed good but was replaced by another chip and the same symptoms occurred.

The timing capacitor was then removed from the circuit and fixed the problem. The voltage on

the timer pin charged to 3.5 V during normal operation and 2 V when a vault condition existed.

The Vbb Protection circuit was fully functional and tested at that time.

After installing the board in the Electronic Cabinet another system test was performed. During

testing all system functions were normal expect the gate pin on the LT1910 chip was 0 V. The

only way that pin would be 0 volts is if the fault pin was low or the timer was below 3.3 V.

Neither of these condition existed and therefore chip must have failed. This chip may have

failed due to overheating during soldering and re-soldering. The chips functionality is degraded

and part of the circuit has been bypassed. Procurement of new LT1910 chips and more testing

will have to been done to find a solution to this problem. There is no adverse affects caused by

this failure to the system.

Although the Vbb protection circuit is degraded and will not open the Vbb line during an over

current condition the circuit will still determine if a fault condition exits. Therefore when the

fault is detected the microcontroller will be informed and can disable the motors and solid state

relay preventing any further damage that would otherwise occur.

4.1.9.6 Full System Fault Analysis

4.1.9.6.1 Overvoltage

After completing a full system test of the driver board the motor filter capacitor was shorted to

the 5 Vdc line (Vdd test pin) and multiple components on the board were destroyed. This was a

catastrophic fault that simulated a very high overvoltage situation which will never happen

during normal operation.

Several components on the board were destroyed including all three A3986 chips (U1, U4, and

U16) and the LT1910 chip (U38). The Vdd pin on each A3986 chip and the IN pin on the

LT1910 chip was shorted to ground. This short circuit condition on the 5 Vdc line caused the

+12Vdc fuse to blow and the +12Vdc fuse blown indicator to light as designed. No other

component failures occurred on the board.

There is no way to protect every component from an overvoltage situation like this. Since the

three A3986 chips were destroyed clamping the input on the Vdd pin so that the voltages will not


49

excide 5 V may reduce the changes of it being destroyed by an overvoltage condition. More

testing and research would have to been done which may greatly out way the cost of just

replacing the three chips.

4.1.9.6.2 Short Circuit of the 5Vdc and +-12Vdc Supplies

A short condition on the 5Vdc, +-12 Vdc line was simulated by shorting each supply to ground.

No component failures occurred. The fuses blew and each indicator lights lit as designed.

4.1.9.6.3 Motor Voltage Supply Failure

The entire enclosure that houses the all components for the electronic system is made from poly

carbonate and is virtually indestructible. The motor supply components are also isolated from

the motor driver and main controller board by a thick piece of poly-carbonate. If the filter

capacitor were to explode it would be contained inside the motor supply housing and no other

components should be affected. If a short circuit condition exists on the motor voltage supply

line the fuse will be blown reducing the changes of this catastrophic failure.

4.1.9.7 Fault Summary

The design failures of the of the +24 Vdc fuse blown indicator have been corrected. The

degraded performance of the Vbb Protection Circuit will not be corrected until further

procurement of the LT1910 chips and more testing occurs.

There are no design failures or faults in the system that will degrade the system performance of

the Motor Driver.

There is no way to protect against ever possible failure that may occur during normal operation.

All possible ways to protect the Motor Driver that were thought of have been implemented

4.1.10 Section Summary

The Motor Driver is designed to drive 3-independent motors which control the movement of the

each axis of the CNC. The driver is designed to be a low cost, high performance product. The

A3986 Dual Full-Bridge MOSFET Driver provided the means to design and implement a low

cost motor driver that is cable of driving motors from 2 to 4.7 amps.


50

4.2 Main Controller Schematic The main controller is designed to take the information for the CPU or any other external device to run

the driver board for the CNC. There are 3 micro-controller chips that were used in this design: the

pic24FJ256GB110 (Communication controller), pic24HJ256GP610 (Motion Controller), and the

ENC624J600 (Ethernet Controller). The communication controller gets information from different

sources: the Ethernet Controller, USB to go, RS232 (Serial port), and the USB to PC. The Motion

Controller then receives information from the communication controller and turns it into data that can

be understood by the Driver Board. In the Motion controller it has one external UART connection that is

hooked up to the Hand Pendent. The Motion Controller also has a handshake to the Communication

controller to flag it that it is ready for more data. The Main Controller also has a Memory bank system

that is controller by an FPGA. This FPGA takes the information coming from the trajectory and places it

into either bank A or Bank B. Bank A and B (IS61LV25616AL) are 256k x 16 high speed asynchronous

CMOS static ram with 3.3v supply. In Figure 1.1 shows the system diagram of how the CNC Main

Controller is connected.

COM

Main Controller

Ether

USB

SerialHandshake

PendantVGA

CPLD

BANK

A

BANK

B

Trajectory

Memory

X

Y

Z

USB to go

Figure 1.1 Main Controller Component connection flow

4.2.1 Communication Controller

The Communication controller is the main source for information coming to

the CNC. This microchip sorts out good and bad packets into the CNC and

determines where information goes. This controller is interrupt driven meaning it


51

waits for information to come to a port and when that port is flagged the

interrupt goes high and all other ports are shut off. On the sheet 3 of the

schematic sheet will show the Communication Controller and the RS232 chip, USB

to PC, USB to go, and the VGA Connector. Also on the sheet 4 of the schematic

sheets show the Ethernet Controller and how it is interconnected.

Note: See schematic D- 3 Main Controller, Communications Processor for more

details.

4.2.1.1 RS232

The serial pin is connected to a MAX3232CDBR chip that is connected to

the RB8 and the RB9 pins on the communication controller. The MAX3232CDBR

chip operates with 3 volt to 5.5 volt VCC supply. This chip is a Multi-Channel RS-

232 Line Driver/Receiver. This device operates with two line drivers and two line

receivers. These input pins are TIN1, TIN2, RIN1, and RIN2. The TIN1 and TIN2

have external outputs going to the Communication controller. The TOUT1 and

TOUT2 are then looped over to the RIN1 and RIN2 pins. The ROUT1 pin goes to

RX1 pin which is port RB8 of the communication controller and the ROUT2 ping

goes to the CTS1 pin which is RB9 port on the communication controller. The

RS232 will bring information from a serial port that is either connected to the

computer or any other external device that has properly working CNC design

software.

Note: See schematic D - 1 Main Controller, Main Processor for more details.

4.2.1.2 Ethernet microchip

This microchip will allow us to have access using an Ethernet port. This

microchip is an already programmed to be able to bring in Ethernet packets and

transfer them through the data ports. On This chip there are 7 Data Ports 15

Address ports that will deal with the data. The Data comes in from the Ethernet

circuit jack (RJ 45) and transfers the information to an internal pin that will act as

a docking station for information coming to the Ethernet and information coming


52

out of the Ethernet microcontroller. The Ethernet also has a pin that will select

the chip to be used. This pin is what will cause the interrupt to be flagged.

Note: See schematic D - 4 Main Controller, Ethernet Processor for more detail

4.2.1.3 USB to GO

The USB to go is implemented into the communication chip. The USB port is

connected to pines RG2 and RG3. The input is on RG2 and the output pin is on

RG3. This chip will control the information that is disconnected from the PC. This

Hand pendent will also receive information from this port to show the files that

are on the USB.


4.2.1.4 USB to PC

The USB to PC port is connected by a USB port to a FT245RL chip. This chip

is connected to the D- and the D+ from the USBDM and the USBDP. The D0- D7

output ports and the RXF, and TXE are connected to the Communications A Bus.

The RD and WR pins are connected to the CPDL connections USB_WR and

USB_RD. The Communications A Bus also connects to USB_CS on the CPLD

Note: See schematic D- 6 Main Controller, PC USB Interface for more details.

4.2.1.5 Serial Port

The serial port is only controlled by 2 pins the RF 13 and RF 12. The input

from the serial port will be the RF12 pin and the Output to the serial port will be

RF13. This is the main connection to the communication controller.

Note: See schematic D- 3 Main Controller, Communications Processor for more

details.


53

4.2.1.6 VGA pin

The VGA connector is connected by a set of 5 pins. The first pin is the VDD

that gives the VGA port power. The second pin is the VGA receive pin. This pin

goes to the Communication controller as the third pin which is the VGA transmit

pin goes to the VGA to display the screen. The fourth pin is the ground pin and the

5th pin is an extra input pin.

Note: See schematic D - 3 Main Controller, Communications Processor for more

details.

4.2.1.7 Communication Data Flow

The information that comes from the 4 input ports are all passed over the

Data lines on the Communication controller. RE0 to RE7 are the home for the D0-

D7 I/O connectors. The address of the data is transferred by PMA0 – PMA15 pins.

The address pins are identified as ADDR_0 – ADDR_15. There are also 2 SPI ports.

One Port is the Handshake for the Motion Controller and the other port is direct

access to the Motion controller for the special functions (See Motion Controller

code SPI 2). The SPI1 pins RD8, RA15, RA14 is the direct connection to the Motion

Controller and the SPI2 pins RD12, RD3, RD2 are the handshake that will be

coming from the Motion Controller. This chip also has miscellaneous pins that do

other functions. These pins are:

CS_A (Chips select for the address) RD7

ALE_A () RD6

RD (Read) RD5

WR (Write)RD4

Bank_Switch( Switches memory banks)RD 13

Bank_Lock (Locks the memory Banks)RC14

Ethernet Interrupt Request RD0

USB Flag RF8

USB Transmit Enable RF2

USB Chip Select RF3


54

Ethernet Chip Select RA1

USB Sensor RB3(Shows if the USB is functioning properly) RB3

MDIX RE8

On the schematic there are other capacitors and resistors that have been placed

on the board. These components were placed due to the chips data sheet

specified how to interconnect them.

Note: See schematic D - 3 Main Controller, Communication Processor for more

details.

4.2.1.8 Motion Controller

The Motion Controller controls the information that comes from the

Communication Controller. The Pic24HJ256GP610 is a 100 count chip that has 9

external terminal blocks that will control the miscellaneous I/O pins and Limit

selections. These terminal blocks are identified on the schematic as TB9 – TB1.

TB9, TB8, and TB2 are all miscellaneous output pins as TB7-TB4 are miscellaneous

inputs. TB 9, 8, 7, 6, 5, 4 are all connected to the Motion controller by Opto-

Isolators. TB2 is a high power output pin which is connected by an Opto-Coupler.

TB 3 and 1 are passed to the circuit having to do with the Limit switches. The

other pins running on the motion controller all deal with other aspects of the

CNC. On the motion controller there are 2 SPI ports one being Master and one

being Slave. There is one UART port that connects the Hand pendent to the Main

Controller.


4.2.1.9 Terminal Block connections

Note: See schematic D - 1 Main Controller, Main Processor for more details on all

terminal block connections.


55

4.2.1.9.1 Terminal Block 1

These connections are used for the limits switches. Pins 1-6 connect the left

and right limits for X and Y and the top and bottom of the Z. These connections

are also connected to 3 and gates that connect to other and gates that connect to

another and gate that goes to the limit interrupt pin on the Motion Controller.

4.2.1.9.2 Terminal Block 2*

These connections are used for miscellaneous output pins 0-3. Pins 1-6 on

the terminal block connect to an Opto-Coupler that then connects to the output

ports on the motion controller.

4.2.1.9.3 Terminal Block 3

These connections are used for the back and forth limits. Pins 1-2 connect

these limits as pin 3 connects to ground and VDD. Pins 1-2 also connect to an AND

gate that connects to another and gate that is connected to the pins from

terminal block 1 that connect to the limit interrupts.


These connections are used for miscellaneous input pins 0-1 that will

connect certain functions from the motor driver board to the motion controller.

Pins 1-4 are connected to these input pins by an opto-isolator.




Pins 1-4 from the terminal block are connected to these input pins by an opto-

isolator.





56

Pins 1-4 on the terminal block are connected to these input pins by an opto-

isolator.





isolator.

4.2.1.9.8 Terminal Block 8**

These connections are used for miscellaneous output pins 6-7 that will

connect certain functions from the motion controller to the motor driver board.


isolator.

4.2.1.9.9 Terminal Block 9**

These connections are used for miscellaneous output pins 4-5 that will

connect certain functions from the motion controller to the motor driver board.


isolator.

4.2.1.10 Pendent Serial Connection

The hand pendent is connected to the motion controller by a

serial interface. These serial interface connections is then connected to

a MAX3232CDBR chip as discussed in section 1.1. The T1IN connection

on the MAX3232 is the pendents transmit port as R1OUT is the

pendents receive port. The pendent reset pin is connected to the CTS

pin on the serial interface. When this bit is set low it is forced to

*Consult the Motor Driver board section for more information of these

miscellaneous input pins

**Consult the Motion Controller code section for more information of these

miscellaneous output pins


57

ground. When this pin is set high the pendent’s connection will reset.

Also the DTR pin on the serial interface will be connected to the

pendent connected pin on the motion controller. When the pendent

losses connection this will be set low and it will shut off. For other

connection information please consult the schematic.

Note: See schematic D-1 Main Controller, Main Processor for more details.

4.2.1.11 Motion Controller pin connections

The motion controller has numerous connections to external connectors.

RA0-RA7 connects the limit pins from TB1 and TB3. The limit interrupt connector

from TB1 and TB3 is connected to INT2 pin. The pendent’s connection pins on the

motion controller are pins RA9, RF3, RF2, and RF1. The miscellaneous input pins

are all connected on the RB8 – RB14 pins and the miscellaneous output pins are

connected on the RD0-RD7 pins. These pins connect all the terminal blocks to the

motion controller. The serial ports (SPI1 and SPI2), which control the handshake

and the direct connection from the communication controller, are all connected

by the motion controllers specified SPI ports. The CPLD connections D7_B – D0_B

are connected to the RD15-RD8 ports. There are other miscellaneous connections

from other parts of the CNC connection. These connections are:

DATA_AVIL ( Interrupt that flags the

communication controller that

information is ready)-INT1

E-STOP( Emergency stop interrupt) -

INT3

Z-DIR( Z direction)-RB0

Z-STEP(Z Step) -RB1

Y-DIR(Y Direction) –RB2

Y-STEP(Y Step) - RB3

X-DIR(X Direction) - RB4

X-STEP( X Step) -RB5

OENABLE(Output Enable) -RG15

ORESET(Resets the Allegros)-RG14

OM1 (Output signal 1 for micro-

stepping)-RG13

OM2(Output signal 2 for micro-

stepping)-RG12

CS_B(Chip Select B Bus CPLD)-RE3

ALE_B(Address Latch Enable B Bus

CPLD)-RE2

RD_B(Read Enable B Bus CPLD)-RE1

WR_B( Write Enable B Bus CPLD)-

RE0


58


4.2.2 CPLD Connections

The CPLD’s main function is to take data from the communications

controller and add it to a memory bank while simultaneously taking data from the

other memory bank and moving it to the motion controller. The CPLD has Bus A

and Bus B that. Bus A coming and going from the communication controller and

Bus B coming and going to the main controller. Pins TDI, TMS, TCK, TDO, Vccint,

and Vccio are programmable ports for the CPLD. This will be used for firmware

update to the CPLD. Pins CS_A, ALE_A, RD, WR, CS_B, ALE_B, RD_B, and WR_B are

all input pins that will handle the Chip Select (CS) the Address Latch Enable (ALE)

the Read (RD) and the Write (WR). The other pins are the D0-D7 and D0_B, D7_B.

These pins are I/O pins that bring data from the Bus A. For Bus B the control

connections from the CPLD to the Memory Bank A and B are as followed:

Memory Bank A

CS_M1 – CE(Chip Enable)

OE_M1 – OE(Output Enable)

UB_M1 – UB(Upper bits)

LB_M1 - LB(Lower Bits)

WR_M1 – WR(Write Enable)

Memory Bank B

CS_M2 – CS(Chip Enable)

OE_M2 – OE(Output Enable)

UB_M2 – UB(Upper Bit)

LB_M2 – LB(Lower Bit)

WR_M2 – WR(Write)

The data pins in the CPLD and bank A are I/O pins. Data pins D0_M1 - D15_M1 all

connect to bank A on pins I/O0 – I/O15. For bank B the data pins D0-M2 –

D15_M2 are connected to the I/O0 – I/O15 pins on bank B. The address pins on

the CPLD A0_M1 – A15_M1 connect to A0 – A15 on bank A and A0_M2 – A15_M2

is connecter to A0 – A15 on bank B.



59

4.2.3 Timing for the CPLD

The CPLD timing is very important for the Main Controller board. The timing

calculations are determined by take . Taking this function

gives the calculation used to determine the timing needed for the CPLD. When

chip select goes low the Read and Write can be toggled if it is high it will not be

implemented. Figure 1.2 shows the timing diagram for the FPGA. These

parameters have to be followed to have proper data catching on the FPGA.

CS

ALE

RD

WR

BANK_SWITCH

INVALID DATA INVALID

T0 T1 T2 T3

25 ns 25 ns 25 ns

DATA

Figure 1.2 Timing Diagram

4.2.4 Power supply

The power supply for the main controller is a 7 volt DC power source. This power

source goes through 2 Voltage regulators VREG1 and VREG2. VREG1 is connected

to 3 fuses and 3 LED’s. These fuses and LED’s show will give verification to the


60

owner of the board that there is a fault in the system. If LED 2 is on the Main

controller (MAIN_3V3) has a blown fuse. This procedure is the same for LED3,

LED5 and LED4. The Main controller the Ethernet and the USB all take 3.3 volts.

Note: See schematic D - 5 Main Controller, Power Supply for more details.


61

4.3 Pendant Subsystem

4.3.1 Introduction

The pendant subsystem is the subsystem that works between the inner

subsystems and outside users. It is composed of the hardware and firmware

subsets. The hardware subset is based upon the schematic layout and inner

processes that occur when a user presses a button on the pendant. It also shows

the complete layout that is seen by the user. The firmware subset is broken up

into the driver block and the main block. The driver block is chosen either

between interrupt or non-interrupt based implementation. After an

implementation is chosen, the state diagram for movement of commands from

key presses is created to illustrate and build coding for transfer of information on

different screens. The main block will show how each message is dispatched

through the system and how graphics functions are created to build the functions

for the screens which the user will use to navigate the machine and gather

information through the microcontroller sub system.

4.3.2 Hardware Subset

This subset will contain brief descriptions for the architecture of the

schematic, PCB layout, and physical reactions to the microcontroller when

buttons are pressed.

4.3.3 Schematic Design

In order to allow the user access to the outside parameters of the CNC and

control movement of the machine, a hand pendant must be designed in order to

give this function accessibility. In order to see the main board view and top board

view of the pendant, turn to the given schematics of E1 and E2 in the appendix of

the report.

The benefit of this particularly designed hand pendant is to allow the user

the ability to access certain internal functions of a job through buttons, change

speed through an exterior feed pot, and visual display of certain items through an

LCD screen which will all receive this information with communication with the

main controller board.


62

The configuration shows how the pendant will receive information through

its cable link from the PIC 24 microcontroller. The DB9 and Max32 chips will work

together to receive and transmit information received through the

microcontroller board. The inputs RBO and RB1 will act as the high and low

connections signals. They will send this information to the pendant

microcontroller through inputs RB2 and RB3. Later, the information will be

relayed from the outputs RB5 through RB8 and RB10 to a group of four buttons

which the user is able to access the information from. The voltage regulator will

receive a 5 volt input and produce a regulated 3.3 volts for the microcontroller to

use. The clock chip will provide an oscillation for the microcontroller to allow a

steady, constant flow of information. The MCPIDE chip will attach to the

microcontroller through its MCLR pin to reset the operations of the

microcontroller. The AN0 pin of the microcontroller will attach to the

potentiometer to allow feed/speed rate changes of the machine through the

pendant’s exterior feed pot. Output RB11 will attach to an LED which when lit will

show the pendant microcontroller is operating and ready to receive information.

Outputs RB12 through RB14 of the pendant microcontroller will be connected to

the LCD screen for the screen’s ability to received information, send information,

or reset if needed. Output RB10 of the pendant microcontroller will also move to

the top board schematic to give connection to the other four buttons of the

pendant. Each button is connected to the microcontroller with a resistor to

prevent any button to short out another button. Capacitors are used between

inputs and outputs of certain chips to shunt high frequency noise and to prevent

switching problems from occurring within the chips. Other capacitors between

VDD and ground are used to prevent energy losses when switching occurs and

prevent ripple in voltage outputs [1].

4.3.4 PCB and Physical Layout

Based upon the design of the previously discussed schematic, the PCB

layout must be constructed to fit within the structure parameters of the pendant


63

box and prevent electrical problems from occurring. In order to see the PCB

layout of the pendant, turn to the given diagram provided in the report appendix.

In order for the pendant board to fit inside the pendant box, the size of the

pendant board must be designed in order to meet these specifications. The size of

the pendant will be based upon the size of an adult human hand to fit the

pendant while the user is able to press buttons with their other hand while still

holding the pendant. The top four set of buttons which will control the function,

cancel, enter, and axis switch tasks will be set up to fit below the LCD screen and

feed pot dial inside the upper section of the box. Therefore, the upper section

must have a larger width to contain the set of switches that are spaced apart on a

horizontal line. To meet this criterion, the upper section will have a width of 5

inches and a length of around 2.5 inches. The lower section will contain the

directional buttons to allow movement of the machine on different axes

depending upon the designation given by the axis switch button. They will be

spaced in square containment area with the all the buttons separated from each

other an equal distance pointing in the direction of movement that each button

will provide on the table top. To meet this criterion, the lower section will be set

up to have a width 3 inches and a length of 3.5 inches. The figure below will

illustrate how the pendant will look once completed.


64

LED Screen

Function Cancel Enter Axis Switch

Up Y/Z

Axis

Le

ft X

Axis

Rig

ht X

Axis

Down Y/Z

Axis

Feed Pot

Dial

Figure 6: Pendant Structure

The PCB Layout of the pendant is built with the bottom layer containing all

the chips, link cable connector, and the LCD screen and the top layer containing

the switches. The red layer corresponds as the bottom copper layer and the green

layer corresponds as the top layer. The bottom layer shows many of the chips

bound into the same small area. This is due to the length of traces that must be

kept at certain length and direction to prevent internal electrical issues. The

traces must move at a 45 degree angle to prevent current losses from occurring


65

when moving from pin to pin. The longer the traces cause a greater possibility

that internal inductance will grow into a large range and affect output current.

Also, shorter traces will provide another method of noise reduction and prevent

resistance drops along traces to read the optimum outputs.

4.3.5 Physical Display after Button Press

After any button is pressed, the pendant and microcontroller begin sending

and receiving messages between each other. The pendant has either the choice of

requesting information from the microcontroller through any of its

communication pathways and direct it to a particular screen created in the

firmware. Otherwise, the pendant can use its LCD screen to present current

information from the table top and navigate the tool head to any part on the

table top. A block diagram of the button press is displayed below.

Which

Process

Button

Press

Display Request

Info

Figure 7: Button Press Process


66

5. Firmware

5.1 Communication Controller:

The communication controller’s task is to receive our information from

four different ports: serial, Ethernet, USB to go, and USB to PC. We also had one

output port (VGA) that would receive visual information as to where the CNC was

positioned and, what state it was in. . The information that goes through the

Controller board is called a Packet. The packet contains the Preamble, the packet

size, the Datagram(s), and the Post-amble.

|------Preamble-----|------Packet Size------|-------Datagram------|------Postamble-----|

15 bytes 512034 bytes 3+N bytes 15 bytes

S0

S1

S2

S3

Our code design was made into 4 main states: listening, preamble,

receiving, and post-amble. The listening state waits for an interrupt to flag that

information is being received. The preamble state determines if the information

S0 – Listening State

S1 –Preamble State

S2 – Receiving State

S3 – Post-amble State


67

being received from the PC is credible information that will be used for the CNC.

The third phase, receiving state, will determine the destination of the information

packet. The fourth and final stage which is the post-amble state will validate the

information’s credibility from the PC. The Post and Preamble states are

interconnected with each other. This way the information is checked twice to

make sure it is correct.

5.1.1 Listening State:

The listening state sits and waits for information to be given to CNC from

the PC. This state is driven by interrupts on the communication controller. Each

input port when it receives information tells the communication controller that

there is data ready to be transmitted. Once the communication controller is told

that is has data ready it triggers an interrupt flag for that port and all other ports

are shut off till the packet is finished being processed. Once it has finished

processing, the interrupts are all reset and more data can be accepted.

5.1.2 Preamble State:

The Preamble’s main duty is to search for the appropriate sequence to

show the information is valid. The Preamble sequence comes directly before the

receive state and looks for a 15 byte sequence with three phases with each phase

having 5 bytes. The first phase of the preamble searches for the Hex value

FF(0xFF), The next phase is looks for 00(0x00) and the final phase searches for AA.

Figure 1 shows the preamble sequence in the order it will be read.

FF FF FF FF FF 00 00 00 00 00 AA AA AA AA AA

4.1.1 Preamble sequence

5.1.3 Receiving State:

The Receiving state transfers our Datagram through our Controller board.

The Data gram consists of 3+N bytes. The first byte in the Datagram is the

Command Id which is then followed by the Datagram size witch is 2 bytes long.


68

The Nth bytes are the Data. In figure 4.2 shows the structure of the Data Gram

that will be passed to the Motion Controller.

CMD SIZE DATA

4.1.2 Data Gram

The Controllers states consists of 7 internal states: Command ID, Com Controller,

Main Controller, Trajectory Memory, Process Com Command, Transfer Via SPI1,

Store Into Memory, Post-amble (Phase 4). The Command State determines what

path the data will go. There are three main paths: Communication Controller,

Main Controller, and the Trajectory Memory. To determine what path to take it

uses the command ID. Figure 4.1.4 shows the state diagram for the

communication controller.

Command ID

The Command ID has 129 groups. Groups 0-20 is designated for the

Communication Controller, 21-40 are for the Main Controller, and 41-128 is

designated for the Trajectory Memory. Figure 4.1.3 shows the group ID table for

the Data Packet.

Destinations ID Group

Com Controller 0 - 20

Main Controller 21 - 40

Trajectory Memory 41 - 128

Figure 4.1.3

5.1.4 Group ID

If the group ID is between 0-20 the next state that it goes to is the

Communication Controller. At this state if the byte counter is less than the

Datagram size then it will loop until it is equal. Once this state is satisfied it then

passes the datagram to the fourth state which is the Process Communication


69

Command. Once it reaches this state if the byte count is not equal to the actual

size of the data then it will be go back to the Command ID state and restart. If this

state is satisfied then it will go to the Post-amble state.

If the group ID is in the range of 21-40 the next state that it goes to is the

Main Controller. Once it reaches this state, it will pass to the state that will

transfer the information via the Serial Port Interface 1 (SPI1). Once the data

reaches this state the next state is the Post-amble. The only requirement needed

for the data to pass to this state is that the byte count has to equal the data size.

If the group ID is between 41-128 the next state that is goes to is the

Trajectory Memory. This state is designed for all types of data that deal with the

plotting data of the CNC. This state is the only state that stores information in the

memory. The reason for it being added to the memory is so two data

transmissions can happen at the same time. At this state if the data count is less

than the data size it loops till this requirement is satisfied. Once the count is equal

to data size it moves the data to the Memory. In this state there are two options.

The first option is if the Data Count is less then the Data Size is goes directly to the

Command ID state. This is in place to show there might have been some Data loss

and it needs to resend the information. If the byte count is equal to the byte size

then it goes to the post-amble state.


70

S0

S1

S2

S3

CMDID <21

CMDID <41

CMID <MAX ID

S4

Invalid

Count < Size

Packet Count < Packet Size

S5

S6

Count < Size

Transfer

Complete

Transfer

Complete

S7

Exit

Count = Size

Count = Size

Count = Size

Notify Main

Controller ready

data

Figure 4.1.4

5.1.5 Post-amble State:

The Post-amble state is the same as the preamble state. The only difference

is the sequences. For the Post-amble the sequences are 55x5, 00x5, and FFx5. The

Post-amble must be true before the communication controller will pass on the

data to the Main Controller. If not satisfied then the data is thrown out and the

computer has to resubmit the packet. Figure 4.1.5 shows of the preamble in the

last phase of the communication controller.

55 55 55 55 55 00 00 00 00 00 FF FF FF FF FF

Figure 4.1.5

S0 = Command ID

S1 = Com Controller

S2 = Main Controller

S3 =Trajectory Memory

S4 = Process Com Command

S5 = Transfer Via SPI1

S6 = Store Into Memory

S7 Post-amble


71

5.2 Motion Controller Micro-Processor Code

The motion micro-processor is the controller that powers the driver board.

The purpose of this controller is to control the X, Y, Z axis, the acceleration, and

velocity. The code for this controller is designed to use the Bresenham Line, and

Circle algorithm to move the CNC to its desired position.

5.2.1 Events

There are 5 main events that will be done with the main controller: Data

Available, E Stop, Limit Interrupt, UART interrupt, SPI interrupt. The data available

interrupt will let the main controller know that data is ready to be interpreted to

code to run the driver board. The E Stop interrupt event will stop the CNC

machine for safety reasons under OSHA guidelines. The limit interrupt will stop

the machine at its limits. These limits will be either the static end points of the

CNC base or the soft limits which can be assigned by the user. The UART interrupt

will be used for the pendent.

5.2.2 Initialization

The first step was to initialize the Motion controller. The CNC required

initialization of three timers: two 32-bit and a 16bit timer. The timers are used for

the acceleration and velocity (32-bit) and the 16 bit timer is an extra timer if

needed. The CNC also required initialization of two SPI ports. One port is the

Master port and the other one is the Slave. The slave port is where the

information will come in on from the Communication controller. The Master port

is the handshake from the Motion controller to the Communication controller.

This handshake is used so the Communication controller will know when to send

more data and that the Motion controller received the data. Also a UART pin is

initialized to bring in information from the hand pendent that will do small jobs

on the CNC without the PC’s help. There were seven miscellaneous pins on the

Motion controller that can be programmed to do other jobs or use other forms of

cutting (milling, solder paste dispenser). These pins are initialized to take in an

analog signal and change it to digital, which is called Analog to digital conversion.


72

The last thing that we had to initialize on the Motion Controller was the ports.

Ports A – D had to be initialized to act as an input or an output.

5.2.3 Parameter Table

There are three types of Parameters that need to be implemented into the

code to allow total functionality of the CNC: soft limit, work off set, and home

position. All these Parameters are 16 bytes long. The soft limit parameter is used

to set limits inside of the CNC. The soft limits are usually within the parameters of

the home position. Figure 4.2.1 shows an example of a soft limit compared to the

full size of a CNC base. The next parameter is the work off set. This parameter

deals with placing the distance from a position other than the center. The work

offset could be used when the drawing job needs to be offset to a different

position other than the global zero. Figure 4.2.2 shows an example of the work

offset of the base of a CNC machine. The last parameter that is needed is the

Home Position. This position can specified at start and this position can be called

when there is a tool change or the CNC is coming out of a job. This position can be

set by the user. Figure 4.2.3 shows an example of where this position could be on

a CNC.

SOFT LIMITS

Center

(Global Zero)

Drawing

Position

Wor

k O

ffset

Home Position

Figure -4.2.1 Figure – 4.2.2 Figure –4.2. 3


73

In the parameter table there are 3 movement speeds: Jog rate, Rapid Rate, Feed

Rate. There are also 2 modes the micro-stepping mode and the move mode. The

Jog rate is used when there is a cutting job being done. When the CNC is cutting it

uses the jog rate. This normally has the Z axis in a set position unless it is doing a

3D drawing. The Rapid Rate is used when there is no cutting job but the CNC

needs to move from one position to the other. The feed rate is the speed of the

spindle head. When the spindle head needs to gain more speed for a certain task

the feed rate, which is set by the user, will be adjusted accordingly. The two

modes in the Parameter table deal with the movement of the motors or the

movement of the CNC. The micro-stepping mode will determine how much power

will be powered to the stepper motors controlled by the driver board. The move

mode will determine where the CNC spindle head will move to.

5.2.4 Global Table

The global table is what will hold the global variables for the CNC. This table

includes: feed override, current position, and the command velocity. The feed

override variable will be used to change the feed rate (Section 4.2.3) of the CNC.

This variable will be used for the E-Stop function and any other function that

needs to stop the feed rate of the CNC or change the rate while a job is in

progress. The current position variable will be widely used in the CNC code. This

variable will be used to calculate the Bresenham circle and line algorithms

(Section 4.2.9), setting up the home position, machine position and the current

position which is known as the TPosition in our code. The command velocity is a

variable that will set the velocity of the stepper motors. This variable also will be

used in calculating the acceleration table of the CNC. This table and variable will

be calculated by hand and set up into a table array.


74

5.2.5 Commands

The Main Controller code’s main purpose is to tell the driver board what

commands is needed to job at hand. These commands that will control the driver

board are implemented on the motion controller. These commands are:

GoHome

SetHome

SetWorkOffset

SetFeed

SetAccel

SetMCode

SetSoftLimits

StartJob

EndJob

SetJog

Traverse

o Linear

o Rapid

There are other feature commands that will be implemented at a later time but

time constraints did not allow for them to be added. These commands are:

Circle

Ellipse

These will make it easier for the CNC to make more precise arches. The line

algorithm will do a circle, but the time will be quicker once the Bresenham circle

algorithm is implemented.

5.2.5.1 GoHome

The GoHome command takes the current home position variable and

places it in the MachinePosition variable. This function will be called when the

user wants to place the CNC in the current home position for either tool changes

or when a job ends


75

5.2.5.2 SetHome

SetHome command takes the current position that the CNC is at or the

position that given by the user. Setting the home position will be used at the

beginning of the job. This position will also be used if the CNC is using the

Traverse command when it is put in the absolute mode.

5.2.5.3 SetWorkOffset

SetWorkOffset sets the work offset that I mention before in the CNC. There

are two different offsets for the X, Y, Z, and A positions in the CNC. This code gives

you the ability to select which offset you want to use.

5.2.5.4 SetFeed

This function sets the feed rate for the CNC. As mentioned before the feed

rate sets how fast the CNC moves.

5.2.5.5 SetAccel

The SetAccel rate sets the acceleration of the CNC for the stepper motors.

The acceleration of the CNC will be calculated dynamically in a table array and it

will be used to determine the velocity of the CNC. The acceleration will be set

within an Array variable AccelRate[1000].

5.2.5.6 SetMCodes

The SetMCodes command will be used to set the miscellaneous ports to do

different functions. Port M4 is the spindle head port. When the user prompts the

controller board that it wants the spindle head on, this port is then given the

value of 1 and it is turned on. The other ports 5-7 are used for miscellaneous ports

and ports 0-3 are used as high voltage ports.


76

5.2.5.7 SetSoftLimits

SetSoftLimits function sets the parameters of the X, Y, and Z limits of the

CNC. These limits are use full for having some type of project that doesn’t need

the CNC’s max range. Setting these limits will let the user create a project without

offsetting there routing design on the computer.

5.2.5.8 StartJob

This commands main function is to start the spindle head or any other

device needed for the CNC before any other command is called.

5.2.5.9 2EndJob

This commands main function is to stop the spindle head of any other

device needed for the CNC at the end of the job.

5.2.5.10 SetJog

This command will set the Jog rate for the CNC Machine. This

variable will be set by the user and can be changed at any time during a

job.

5.2.5.11 Traverse

The Traverse command is the main command in the motion controller. This

command’s main function it to implement a line on the CNC. There were two

types of Traverse modes: Linear and Rapid. Linear traverse is when the CNC is in a

routing job. This mode has a very slow acceleration rate so it can cut the material

that the job is calling for. The Rapid traverse mode is for moving the spindle head

to a particular position that it will continue the schematic again. The acceleration

of these two modes will be called from the acceleration table.

5.2.6 Motion Controllers data flow

The motion controller’s data flows very similar to the communication

controller. The motion controller brings in a Data Gram packet. In this Data Gram

there are 3 parts: The command ID, the data size, and the data itself. Figure 4.2.4

shows the structure of a typical Data Gram packet. The command ID packet is the

ID that will call the set of commands that is mentioned in section 4.2.5. Each


77

command is given an ID. Figure 2.2.5 shows a list of all the command ID’s in used

in the code.

Command ID Data Size DATA

Figure 4.2.4

The next part of the data gram is the data size. The data size gives us the

appropriate size of the data packet. This number will be used to as a stopping

point for the counter inside the motion controller. Once the data size equals the

counter of the job the CNC believes the job is over and it then starts searching for

more information that has came from the message query. Figure 4.2.6 shows the

flow of the data gram from the message query. The information is on a FIFO (First

In First Out) procedure. This allows for no skipping of data information. This is the

main reason that the functions that call for positions or any other safety function

comes from the SPI port.

Commands ID

SPI:GoHome 1SetHome 2SetWorkOffset1 3SetWorkOffset2 4SetFeed 5SetAccel 6SetMCode 7SetSoftLimit1 8SetSoftLimit2 9

Memory:StartJob 1EndJob 2SetJog 3Linear Traverse 4Rapid Traverse 5

Figure 4.2.5


78

1

2

3

_

_

_

Message Query

MOTION CONTROLLER

X Y Z

SPI Port

Figure 4.2.6

5.2.6.1 Message Query

The Message query holds the information to be given to the Motion

Controller. The only information that will be placed on the message query will be

any type of trajectory data. The message query code takes the message from the

Communication controller and dispatches it to the message query. Here is where

the data is placed into a FIFO design where once one message is done the next

message in line came directly before that message.

5.2.7 Interrupts

The Motion Controllers specific ports are interrupt driven. The interrupts

are in a range of 7-0, 7 being the top priority interrupt and 0 being the lowest. If

the CNC’s interrupt not set the interrupt is automatically set as a 4. The interrupts

for the CNC are as followed:

Velocity Timer : 7

Acceleration Timer: 6

Limit Switch: 7

E-Stop: 6

SPI Port 1: 4

SPI Port 2 : 4


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UART : 5

Analog to Digital : 3

5.2.8 Files in the Motion Controller Program

C Files:

UART

Timer2

Timer3

Timer4

SPI1

SPI2

Messages

MaiInitialization

Main

Limits

Handle

EStop

Dispatch

DataAvail

AnalogToDigital

H Files:

UART

Timer2

Timer3

Timer4

SPI1

SPI2

Messages

MaiInitialization

Main

Limits

Handle

EStop

Dispatch

DataAvail

AnalogToDigital

5.2.8.1 UART

The UART file has the initialization functions for the UART and also has the

enable function that will enable the UART. The sequence to enable the UART is to

enable the UART1 pin. Next you need to enable the transmitting bit. Next you

need to Enable the transmit interrupt and then the receive interrupt.

5.2.8.2 Timer 4

This file is used to initialize the Timer 4. This Timer is used if another timer

is needed for the CNC. This timer can be used at a later time depending on the

firmware updates.


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5.2.8.3 Timer 3

Timer 3 is the acceleration timer. This timer is used to determine the

acceleration that will be used for the CNC. It also will determine when the

acceleration of the CNC will plain out to its max speed.

5.2.8.4 Timer 2

Timer 2 is the velocity timer. This timer calculates the time of max velocity.

This timer as Timer 3 also will determine the max velocity.

5.2.8.5 SPI1

SPI 1 is the slave port. This port will transmit the handshake to the

Communication Controller. This port will be enabled by flagging the enable the

RF13 port.

5.2.8.6 SPI2

SPI 2 is the master port. This port will receive the information from the

Communication Controller. This port can be enabled by flagging the enable bit for

port RF12.

5.2.8.7 Messages

The Message file specifies the structure of the data messages that get

transmitted to the Motion Controller. The message structure has a Message ID,

the LPARAM (Parameter 1), and the WPARAM (Parameter 2). It would then

increment the message to place the message into a message packet. Then it will

dispatch the message to the message query.


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5.2.8.8 MainIntialization

The Main Initialization file has all the commands and all the parameters

inside them. It has every position and movement rate, as well as all the Command

pointers for the Handle file.

5.2.8.9 Main

The main files only function is to take the message and place it into the

message query by using the functions GetMessage() and AddToQue().

5.2.8.10 Limits

This file sets all the limits on the Motion Controller Ports.

5.2.8.11 Handle

The Handle file gives each command it’s ID. These ID’s then go to a case file

and are selected by the command ID from the message.

5.2.8.12 EStop

The EStop file is the Emergency stop command. This is command is called

on the SPI port. Once this command is called it is immediately executed.

5.2.8.13 Dispatch

This file dispatches the functions HandleSPIRecieve() and also the

Handle_Data_Avail(). These functions will be called depending on which

command is in the appropriate function from the Handle file.

5.2.8.14 DataAvail

This file controls the external interrupt that tells the motion controller that

the communication controller has information ready to be processed.

5.2.8.15 AnalogToDigital

The Analog To Digital file initializes the miscellaneous ports on the CNC.

This file will hold the functions of the M codes that are used for different abilities

that can be called for the CNC

5.2.9 Bresenham Algorithms

The Bresenham Algorithm is made up of two different types. The line and c

circle Algorithm are made up in the linear and rapid traverse functions. The


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Bresenham line algorithm uses ΔX and ΔY to step to the final position of X and Y.

Since our cutting will be 1/16 of an inch this algorithm will work perfectly. There

will be no visible cuts in the material that looks like we stepped from one axis to

the other. Figure 4.2.7 shows the Bresenham line algorithm diagram that was

used to calculate the line and Figure 4.2.8 shows the equation that was used to

step to each position.

(X,Y)

ΔY

ΔX

The current positions for each Axis is its own variable postion.

X = CurrentPosition.X

Y = CurrentPosition.Y

X) CurrentPosition = ΔX + MachineOffset + CurrentPosition

Y) CurrentPosition = ΔY + MachineOffset +CurrentPosition

Figure 4.2.7 Figure 4.2.8


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5.3 Firmware Subset

When a physical button is pressed, there must be a way for the pendant to

correctly receive information from the microcontroller sub-system. In order to

receive a request from the pendant, an interrupt system must be set up to give

priority for driver processes. After priority is set, it must be sent through the

driver sub-block to generate the events relevant to the message. Afterwards, the

message moves to the main sub-block to move messages to the queue and

dispatch to the appropriate handler. Finally, generalized functions must be

created in the firmware to write graphics to the LED to create the different

screens.

5.3.1 Interrupts

In order for the internal queue of the memory to operate with the ability to

have certain functions have priority over other functions, the message queue

system must be set up where the drivers are interrupt based. Each driver is given

a specific priority based upon which operation must be worked into and out of

the message queue first. The interrupt system will give first priority to scan key

driver, second priority to the analog driver, and equal priority between the display

and serial drivers which will all link into the message queue. The block diagram

below shows how the interrupt system will be based.


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Message

Queue

Serial Drivers Display DriverScan Key

Driver/ TimerAnalog Driver

Hardware

Abstraction Layer

Figure 8: Interrupt Block Diagram

5.3.2 Driver Subset

As stated above, the drivers are separated into priority passing their

information into the queue based upon which driver sent the information. Each

driver will be broken down into more generalized descriptions starting with

highest priority.

5.3.2.1 Key Scan Driver

In order to accept a key scan press, a finite state machine must be created to

accept button presses as starting states which must be validated and released

before any information can move from the drivers. The state machine is set up

below with legend below.


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State So State S1

State S2State S3

S0=Ks_Detect Button Press

S1=Ks_Verify Press

S2=Ks_Detect Release

S3=Ks_Verify_Release

Legend

Figure 9: State Machine for Key Press Interrupt

Within the microcontroller of the pendant, there are two timers that

may activate after a key is pressed depending upon the current state. One timer is

used for detection of the initial key press and scanning row and columns of the

keypad that will last approximately 1 millisecond. The second timer is activated is

used for the debounce of the keypad or verifying the key press which will last for

approximately 30 milliseconds. When going through debouncing, if they key press

is correct, the message will continue and move to the main application from


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whatever driver released it, but if they key press was in error, the state machine

will return to the detection state.

Starting from state 0, when a key is pressed, the state machine will move to

state 1 where the first timer will activate. The machine moves will check for

correctness of the key press in state 1 and if confirmed will move to state 2, but if

not confirmed, it will turn off the second timer if it is running and go back to state

0. After validation, the machine will move to state 2 where the first timer will

deactivate and the second timer will activate which will move the machine to

state 3. Once the key is released, the second timer is deactivated and the first

timer will reactivate and send the machine back to state 0 to respond to another

key press.

The key scan driver will return to state 0 in all cases where either an error

was made or process was completed. As an entire process starting from

initialization, the block diagram of the key scan is presented below.


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Initialization

Timer Interrupt

Toggle=0Set Row High/ Set Flag

Toggle

Next Row

High

Toggle=1

Return

Read Key

Press

Debounce

Read Key

press

Previous=

Current Clear

Toggle

Place in Message

Queue

Yes No

Yes

No

Figure 10: Key Scan Driver

5.3.3 Display Driver

This driver is built for the purpose of creating display functions that

can be repeatedly used for the different screens. This is done by creating

functions with the LCD screens internal datasheet. With the use of hex and C

code, the function library can be created to hold all the functions that can be

used. To build this driver, there is a choice between creating it as an interrupt or

non-interrupt based system. Although the non-interrupt system is simpler to code

and implement, it causes performance problems with the driver sub-system and

contains no loop transition for transmission which can lead to stalled applications.

Pictured below is the display driver if it were in non-interrupt form.


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Transmit Queue

Get Byte/

Set Busy

Flag

Send

Acknowledge

Tx Empty

Complete/

Clear busy

flag

No

Yes

No

Yes

Figure 11: Display Driver Non-Interrupt

In this setup of the display driver, the routine checks to see if data is inside

the transmit queue. If data is waiting, the busy flag is set to prevent any other

operation from occurring or other information from being released. The machine

must acknowledge the byte being sent before it can move, and it checks to see if

the transmit queue is empty. If it is not empty, the routine continues again. If it is

empty, the busy flag is reset to allow other operations to occur.

Pictured below is the setup for the interrupt version of the display driver.


89

Data into

Transmit

Queue

Build

Command

Structure

Busy

Enable Tx

Interrupt

Initial First

Byte

Transfer

Return

TX

Interrupt

Flag

Get Byte

from

transmit

queue

Last

character

Disable Tx

interrupt

flag/ Clear

busy

Return

Service

Routine

Yes

No

Yes

No

Service

Routine

Figure 12: Display Driver Interrupt

In this setup, the data is moved into the transmit queue. A built command

structure must be created to move the information out of the queue and into the

message loop. If the driver is busy, no data can be moved until the busy flag is

released. After data is completely filled into the transmit queue, the interrupt

process begins and sets the interrupt flag on. The first character is moved quickly

to the message loop, and the routine checks for another character and moves it

to the message loop until the queue is empty which disables the interrupt process

and clears the busy flag again. Afterwards, the routine will return to its original

status.


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5.3.4 Analog Driver

This driver is a connection to the feed pot discussed in the hardware

subset. Any change in the feed pot dial will be stored as an analog value which

must be sent through the driver to the message loop to be converted into digital

information and be used by machine to change the speed/feeds of the machine

while in motion. The block diagram for the analog driver is pictured below.

Initialize

Analog

Drive

Get Value

Current

Value=Previous

Value

Put in

Message

Queue

Return

Yes

No

Figure 13: Analog Driver Diagram

The diagram shows that after initialization it will check the value the

feed pot is currently displaying and comparing it to the value it last checked it as.

If the previous value is not the same as the current value, the value will be placed

into the message queue to be sent to the microcontroller to change the

speed/feed rate. If the values are the same, the routine will return to

initialization.


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5.3.5 Serial Driver

This driver is the main connection between the serial port that runs directly

to the microcontroller sub-system and the pendant sub-system. This driver has

access to the Tx transmit queue and Rx receive queue. When information is

received through the transfer queue from the microcontroller sub-system, it is

processed byte by byte until it is completely moved in the message loop. Also, if

information needs to be stored from the receive queue, it must move each byte

of the message until it has been completely processed. The block diagram for the

serial driver is displayed below.

Main Initialize

Tx Queue/ Tx ISRRead Queue/

Rx ISR

Get byte from

Tx buffer

Store received

byte

Check Tx

queue emptyReturn

Disable

Interrupt/

Clear Busy

Return

End of

transmissionReturn

Send Message/

Clear

Acknowledge

Return

No

Yes

No

Yes

Figure 14: Serial Driver

As shown in the diagram depending upon which queue branch was

taken, each byte of information is stored or read, and if more information is

detected, the loop will repeat. Otherwise, the busy signal is cleared to allow other

operations to occur and will return to main.


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5.3.6 Main Subset

The subset contains all blocks for correct dispatching of the message after

exiting the message queue.

5.3.6.1 Message Loop

After exiting the message queue, the command information is sent to the

message loop where it will either be dispatched or go back into the message loop

after being dispatched. Each dispatched message has to be delegated to the

appropriate handling method. The four main types of dispatched messages are

either serial events, display transmission finished, analog value changed, and key

pressed. Serial events can either be transmission completed or a request to

receive data. The message transmission path is shown in the figure below.

Message

Loop

Dispatch

Message

From Message

Que

AL

Application

Layer

Figure 15: Main Subset

The message loop is either set to 0 or 1 input. Based upon interrupt

priority, the message loop will grab the message from the message queue that

has the highest priority. Afterwards, it will call the dispatch message command. It

will then return to the message loop. The message will be set to 0 if there is a


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message or be a 1 if there is no message in the loop. Finally, it will decrement the

message counter. The message loop block diagram is pictured below.

Get from queue

Decrement Counter

Return

Figure 16: Message Loop

5.3.6.2 Dispatch Message

The dispatch message block is set up by a menu index that determines the

current state of the machine. After any of the buttons are pressed, a different set

of operations are performed to send the correct information and determine the

action wanted by the user. After information has moved through this block and

graphics commands are written to make screen displays, it can be shown any

multiple screens for reading or altering. The main block with major sub-blocks for

the dispatch block are shown below.

Handle Key Press Menu

Function Jog Cancel Accept

Figure 17: Dispatch Menu Main Block


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The menu for the key press can either be set at 0 through 4. Index 0 stands

for the machine in no motion in idle state. Index 1 stands for the machine moving

into function set of sub-screens. Index 2 stands for the machine in motion in jog

state. Index 3 stands for the machine opening a file from an outside jump drive.

Index 4 stands for the machine being locked and unable to accept any new

commands.

5.3.7 Function Sub-block

This sub-block allows the user to enter the main set of function

screens that will be discussed in greater detail later. Pictured below is the block

diagram for the function sub-block.


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Function

Display

Function

Menu

Key

Index=0

Return

Figure 18: Function Sub-Block

5.3.8 Jog Sub-block

In this sub-block, the index is checked to see its immediate placement to

allow a different command to be utilized depending on the state. If index is 0, the

routine will return to the main loop. If index is 1, next function menu will be

displayed. If index is 2, a jog command can be sent. If index is 3, the directory to

the jump drive will be displayed. If index is 4, the display is locked and no

operation can changed until it returns to the main loop. Finally, if the index is

outside the range, it has entered an unknown state and must immediately return

to the main loop. The block diagram for the jog sub-block is displayed below.


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Figure 19: Jog Sub-Block

5.3.9 Cancel Sub-block

In this sub-block, after the key index is set to 0, the current coordinate set

will be displayed if on the main screen or it will return you to the main screen if in

a lower screen. The block diagram for the cancel sub-block is displayed below.

Jog

Key=0 Return

Key=1Display

Next MenuReturn

Key=2Send Jog

CommandReturn

Key=3Display

DirectoryReturn

Key=4

Display

Unknown

State

Return

Display

Locked

YesNo

Yes

Yes

Yes

Yes

Yes

No

No

No

No


97

Figure 20: Cancel Sub-Block

5.3.10 Accept Sub-block

In this sub-block, after function sub-block is initiated, it provides movement

to the lower set of screens and executes files loaded from the jump file which will

return to the default screen. Pictured below is the block diagram for the accept

sub-block.

Cancel

Set Key=0

Display

Coordinate

Return


98

Figure 21: Accept Sub-Block

5.3.11 Directory Block

This block is a sub-block under the jog block. After it has been selected

through the flowchart, it opens up the directory to the outside thumb drive. After

opening the drive, it gives access to the folders within the directory and the files

within each folder. Pictured below is the block diagram for the directory block.

Accept

Go To

Selected

Screen

Execute

File

Return To

Default

Screen

Main

Screen


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Thumb Drive Initialize

Button Press

Accept

Left

Right

Up

Down

Function

FileLoad File/

Run Job

Change

Directory

Update

DisplayExit

Get

Request

Next File

Refresh

DisplayExit

Get

Previous

File

Refresh

DisplayExit

Go To

Main

Go to

Main Sub

Screen

Yes

No

No

No

No

No

Yes

No

Yes

Yes

Yes

No


100

Figure 22: Directory Block Diagram

5.3.12 Graphics

In order for the function blocks to communicate directly to the screens and

display the corresponding information, firmware graphic functions must be

written to give the writer access to information from the microcontroller sub-

system and correctly move it to the pendant screens. Listed below is a table with

the created functions and a brief description for each one [2].

Name Description

MoveTo()

Moves x and y pixels on LCD screen to

new position

DrawLine()

Draws a line on a screen in a specified

position

DrawBox()

Draws a box on a screen in a specified

position

DrawChar()

Returns a character from a specified

position

DrawCircle()

Draws a circle on a screen in a

particular position

DrawTriangle()

Draws a triangle on a screen in a

particular position

RowColumnPos()

Moves a character to specified x and y

array positions


101

SetOpaqueTransparent()

Used in conjunction with DrawBox()

command to set background to

opaque or transparent

SetBackgroundColor()

Set background color to a set of

written, predefined colors for the LCD

SetPenSize()

Sets pen size for the drawing

DrawSemiCircle()

Draws a semi-circle on a screen in a

particular position

WriteString()

Writes a string of characters starting at

placement stated by RowColumnPos()

command

ClearScreen() Clears screen of all previous images

and information

DrawIcon() Draws an uploaded icon to a particular

position on the screen

Table 1: Graphics Functions

5.3.13 Screens

This section will describe each screen displayed on the LCD of the pendant

with its related use and how it receives information from different sources [2].

5.3.13.1 Main Screen

This is the default screen for the LCD. After startup, the pendant will display

the current x, y, and z coordinates of the pendant with the current acceleration

directly below sent through the microcontroller sub-system. On the top right,

there will be an odometer displaying changes made to the speed through the feed

pot potentiometer. At the bottom left, there are five circles that are either red or

green to tell the user when the limit of a switch is on or off based upon


102

preferences given by microcontroller sub-system. Finally, the bottom left will

display a text box that will read run, jog, or idle depending upon the current state

of the machine.

X:

Y:

Z:

A:

JOG

-50 50

Figure 23: Main Screen

5.3.13.2 Main Sub-Screen

This is the first screen that will appear once the function key is pressed

allowing the user to move into the lower sub-screens.

Subscreens

- Offsets

- Parameters

- Soft Limits

Figure 24: Main Sub-Screen

5.3.13.3 Offsets Screen Menu

This sub-screen will be broken up into four different screens that the user

can access and alter.


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Offsets

- Home Position

- Park Position

-Work Offset 1

-Work Offset 2

Figure 25: Offsets Screen Menu

5.3.13.4 Home Position/ Park Position/ Work Offset 1/ Work Offset 2 Screens

These screens will all display different information depending upon what

the user previously set up each screen’s values as or what the job the machine is

performing may set them as. These screens will have a title at the top displaying

the current screen. On the left side, there will be a title to show the set values for

the x, y, and z positions and the acceleration rate. On the right side, there will be

a title to show the current values for the x, y, and z positions and the acceleration

rate that are currently being processed on the machine while in motion. At the

bottom, there are accept and cancel boxes that can be used with their

corresponding buttons to accept the set position as the current position or cancel

and return to main screen.


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TitleSet

PositionCurrent

Pos

X:

Y:

Z:

A:

Accept Cancel

Figure 26: Offset Screen

5.3.13.5 Parameters Screen Menu

This sub-screen will give the user access to the machine parameters, TCP/IP

configuration, and communications port screens.

Parameters

- Machine Parameters

- TCPIP Configuration

- Com Port

Figure 27: Parameters Screen Menu


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5.3.13.6 Machine Parameters Screen

This screen will display all the parameters that the machine is limited to

working at. These parameters are specified through the outside connection’s

requirements, jump drive requirements, or the default rates the machine can

move it based upon the drive sub-system’s limitations for stepping.

Machine Parameters

Max Speed:

Acceleration:

Rapid Max:

Rapid Min:

Deceleration:

Jog Speed:

Max Jog Speed:

Max Feed:

Min Feed:

Jog Increment:

Figure 28: Machine Parameters Screen

5.3.13.7 TCP/IP Configuration Screen

This screen will only show information when the machine is operating

through its Ethernet connection. These variables will show the addressing from

different protocol layers that are hardwired into the connection bus depending

upon where the outside connection is being made. The information is relayed

from the microcontroller sub-system.


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TCP/IP Configuration

Ip Address

xxx.xxx.xxx.xxx

Subnet Mask

xxx.xxx.xxx.xxx

Default Gateway

xxx.xxx.xxx.xxx

xxx.xxx.xxx.xxx

Primary DNS

Secondary DNS

xxx.xxx.xxx.xxx

Figure 29: TCP/IP Configuration Screen

5.3.13.8 Communications Port Screen

This screen will only display information when the machine is operating

under the serial connection. These variables displayed will show the rate at which

the bytes are being moved into the machine, the bytes that distinguish the end of

the transmission, the bytes representing how the flow of information is being

controlled, the bit to show if the information has a certain type of parity, the bits

to show the on character and off character if the flow control is moving in this

pattern. All this information is sent to the pendant through the microcontroller

sub-system.


107

Com Port

Communications

Baud Rate

Stop Bits:

Flow Control:

Xon Char:

Xoff Char:

Parity:

Figure 30: Communications Port Screen

5.3.13.9 Soft Limits Screen Menu

This sub-screen will allow the user to move to the upper and lower soft

limits screens.

Soft Limits

-Upper Limits

-Lower Limits

Figure 31: Soft Limits Screen Menu


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5.3.13.10 Upper Soft Limits/ Lower Soft Limits Screen

These screens have the same setup as the offsets’ screens. The title is

centered showing which limits are being displayed. The left side displays the set

values for the x, y, and z positions and the acceleration rate, and the right side

displays the current values for the x, y, and z positions and the acceleration rate.

The bottom shows the accept and cancel boxes to change the set values to

current values or go back to the main screen. This information is provided by the

job the machine is performing or can be specified by machine limitations given by

driver and microcontroller sub-system constraints.

Upper Limits/Lower LimitsSet

PositionCurrent

Pos

X:

Y:

Z:

A:

Accept Cancel

Figure 32: Upper Soft Limits/Lower Soft Limits Screen

5.3.13.11 Thumb Drive Screen

This screen will display the entire directory for the uploaded jump drive file.

The top of the screen displays the name of the jump drive. Below, the directory


109

names with an icon are shown for all folders. If a folder is chosen, the directory

names with an icon are shown for all files.

Root:

Folder Name

File Name

Figure 33: Thumb Drive Screen

5.3.14 Relation To Other Sub-Systems

Mechanical Sub-System: Connection to outside structure through a serial port

connector; able to control movement of mechanical gantry through set of buttons

that can be switched to control either y or z axes and x axis simultaneously

Microcontroller Sub-System: Receives information that can be displayed by

screens and can send information back to system to change current information

to set information on the table.

Driver Sub-System: Receives power for operation from this system


110

6. Conclusions and Recommendations

6.1 Conclusions

The CNC machine is a system that accepts numerical input and performs

machining on a part or product based upon the provided tool head’s function. It

has an estimated life expectancy of at least 15 years. It has negative impact on the

environment through either noise pollution and may cause adverse affects on an

individual’s health if the electrical components contain any poisonous elements. It

can be manufactured quickly if all schematics, firmware, and software are

provided and cost being of small concern. This system can replace many products

that perform only one particular function and can only accept certain types of

input files. Its cost is lower than many similar machines currently on the market,

and it is adaptable to be useful for both manufacturers and hobbyists. The

machine is broken down into these four subsystems.

Mechanical

Motor Driver

Main Controller

Pendant

6.2 Recommendations

This system is able to add more features, improve current features, and

develop new facets. Some possible improvements and additional testing to the

current system are listed below.

Combine ENC and PIC24F processors by using newly invented PIC32

processor

Add more interface screens to pendant

Expand miscellaneous input/output space from main controller to motor

driver


111

Implement Bresenham circle algorithm and ellipse function into FPGA for

the main controller subsystem

Design independent power supply for each subsystem

Provide additional axes for movement

Reduction in size of motor driver PCB board

Use more miscellaneous outputs on motor driver board to control voltage

reference circuitry to set maximum current through motors

Provide protection circuit in series of motor driver’s bridges to maintain

micro-stepping sequencing

Create extra tool head attachments

Perform FEA finite element and stress analysis testing on gantry

components

Calculate bearing deterioration, bushing wearing, and ball screw wearing

7. Cost/Manufacturability

In order to make this product marketable, a range of costs must be found

that can show the machine can reproduced at a lower cost compared to the

amount given by the original prototype. After creating a working prototype, prices

have been calculated for the major costs for the system. They are displayed in the

table with a price given at a large quantity that is given to the buyer after a

certain time has passed.

Part Cost Quantity Waiting Time

Motor Driver PCB Board $25 5 4 weeks

Pendant PCB Board $13 10 4 weeks

Main Controller PCB Board $13 10 4 weeks

Plastics $ 384 each 50 N/A

Parts Pendant $ 50 each 50 N/A

Parts Driver $ 120 each 50 N/A

Parts Main Controller $ 100 each 50 N/A


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Cabinet $40 1 N/A

Assembly Electrical Reflow $ 25 each 3 N/A

Total $770

Table 2: Manufacturability Costs

List of Equipment and Materials with Prices

Equipment Location Soldering Iron Borrowed from James Williams

Reflow Iron Borrowed from James Williams

Mill Loaned from University

Table Saw Loaned from Norva Plastics

Materials Price (each in $) 1 BAV16W-FDICT-ND Diode .18

9 CC0805 0.1uF Capacitor .05

3 CC0805 1uF Capacitor .04

3 CC0805 4.7uF Capacitor .08

1 CTX736CT-ND Chip 7.35

1 DB9/RS232 Chip .50

1 HEADST10 Dual Row Header .10

3 Single Row Headers .05

1 MAX3232CDBR_SOIC chip 2.45

1 MCP1825T-3302E Voltage Regulator 1.04

10 Mounting Holes Free

1 PIC24HJ32GP302/SOIC28 Microcontroller 4.82


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1 RC0805 1M Resistor .07

2RC0805 47K Resistor .07

5 RC0805 1K Resistor .07

1 RC0805 4.7K Resistor .07

2 RC0805 100K Resistor .07

1 RC0805 240 Resistor .07



1 SMD_LED0805 LED .40

8 SW415-ND Switches .60

1 VRT24W Variable Resistor 1.55

PCB Board 33.00

1 OLED Display 79.00

Frame Free

The boards will come completely assembled after purchase, but time

required to machine and align complete system will take 1 day. The electrical

control box will take .5 days to complete, and system testing will take 1 to 2 days

to complete.

7.1 Mechanical Cost


114

Component Part #

Quantity Cost Total Cost Source Date Priced

Common Parts (X, Y, & Z)

Ballscrews 108" $10.09/ft $ 90.81 Roton 1/24/2010

Ballnuts 3 $ 23.55 $ 70.65 Roton 1/24/2010

Thrust bearing blocks

3 $ 11.75 $ 11.75 Stock from Online Metals, machined in house

Ballnut flanges

3 $ 3.38 $ 3.38 Stock from Online Metals, machined in house

Thrust Bearings

6 $14.95/2 $ 44.85 VXB

Grease Zerks: 1/8-27 PTF

3 $2.90/10 $ 2.90 McMaster Carr

Ball Bearings

3 $ 5.55 $ 16.65 McMaster Carr 3/29/2010

Bearing seals

6 $ 2.31 $ 13.86 MSC Direct

Seal retainer

3 $1.25/3 $ 1.25 Stock from ME shop, machined in house

Belts 3 $ 3.49 $ 10.47 McMaster Carr

Pulleys 6 $ 3.17 $ 19.02 MSC Direct 3/23/2010

Motors X&Y 2 $ 39.00 $ 78.00 Anaheim Automation

Motors Z 1 $ 29.00 $ 29.00 Anaheim Automation

Wiring 20ft 3 $ 13.00 $ 39.00 Anaheim Automation

Cable Carriers

Cable Carrier (X & Y)

2 $ 41.19 $ 82.38 McMaster Carr 3/29/2010


115

Mounting Brackets (X&Y)

2 $ 8.58 $ 17.16 McMaster Carr 3/29/2010

Cable Carrier (Z)

1 $ 10.66 $ 10.66 McMaster Carr 3/29/2010

Mounting Brackets (Z)

1 $ 6.96 $ 6.96 McMaster Carr 3/29/2010

Z axis

z-top 1 Quoted Machined by Norva Platics

z-side 2 Quoted Machined by Norva Platics

z-bottom 1 Quoted Machined by Norva Platics

z-back 1 Quoted Machined by Norva Platics

z-mount 1 $ 18.23 $ 3.04 Stock from Online Metals, machined in house

standoff 2 $ 9.85 $ 9.85 Stock from McMaster Carr, machined in house

3/29/2010

versa rail 2 $ 40.30 $ 80.60 Anaheim Automation 1/27/2010

versa guide block

2 $ 33.80 $ 67.60 Anaheim Automation 1/27/2010

Spindle Plate

1 $ 10.94 $ 10.94 Stock from McMaster Carr, machined in house

3/29/2010

Spindle 1 $ 22.00 $ 22.00 James Williams

spindle holder

1 Quoted Machined by Norva Platics

X axis

x-traveling block

1 $ 105.00 $ 105.00 Stock from Norva Platics, machined in house

xback 1 Quoted Machined by Norva Platics


116

xtop 1 Quoted Machined by Norva Platics

x-rods 3 $ 39.35 $ 118.05 Lintech

x-bushings 6 $39.95/4 $ 59.93 VXB

Table

Table sides 2 Quoted Machined by Norva Platics

Table Bottom


Table end -Motor


Table End 1 Quoted Machined by Norva Platics

Table Top 1 Quoted Machined by Norva Platics

Table supports

3 $ 8.69 $ 26.07 Stock from Online Metals

4/7/2010

Table stand rails

2 $ 10.62 $ 21.24 Stock from Online Metals

4/7/2010

Y axis

sides 1 Quoted Machined by Norva Platics

side w/o motor


y-cross 1 $ 18.23 $ 15.19 Stock from Online Metals, machined in house

y support rail

1 $ 179.00 $ 179.00 VXB 1/28/2010

y-axis bushing block

2 $ 39.95 $ 79.90 VXB 1/28/2010

y-lifts 2 $ 57.33 $ 57.33 Stock from Online Metals, machined in house

Machine Electronics


117

Electronics Case

Top 1 Quoted Machined by Norva Platics

Bottom 1 Quoted Machined by Norva Platics

Sides 2 Quoted Machined by Norva Platics

Front 1 Quoted Machined by Norva Platics

Back 1 Quoted Machined by Norva Platics

Divider 1 Quoted Machined by Norva Platics

Pendant Case

Case 1 Quoted Machined by Norva Platics

Back Plate


Fasteners

M5x20 8 $5.34/25 $ 1.71 McMaster Carr 4/7/2010

M6x25mm

8 $7.91/25 $ 2.53 McMaster Carr 4/7/2010

4-40x0.25

24

6-32x0.25

17

8-32x0.375

2

8-32x0.5

12

8-32x1 68

10-24x0.75

12 $7.94/100 $ 0.95 McMaster Carr

10-24x1

148 $16.15/100 $ 23.90 Fastenal 4/2/2010


118

1/4-20x1

77 $9.45/50 $ 14.55 McMaster Carr

3/8-16x1.5

10 $ 9.79 $ 9.79 Lowes

3/8-24x1

4 $8.27/25 $ 1.32 McMaster Carr 4/7/2010

8-32x0.25 (self tapping)

4

5/16-16 Nut

3

board standoffs

6-32x0.3125 7

6-32x0.3125 10

4-40x0.25 4

set screws

8-32x0.25 3

8-32x0.3125 1

Washers

Split Lock washers

#10 32 $2.13/100 $ 0.68 McMaster Carr

1/4 56 $5.64/100 $ 3.16 McMaster Carr

3/8 16 $4.00/25 $ 2.56 Lowes

M5 8

M6 8


119

Ext. Tooth Lock washers

#10 110 $2.54/100 $ 2.79 Fastenal 4/16/2010

Flat washers

3/8 8

.438x.203x.032

24

.500x.265x.032

36

Fastener Totals

Unlisted $ 30.00 $ 30.00

Paste Dispenser

motor mount


plate 1 $25.34/3 $ 8.45 Stock from Online Metals, machined in house

plunger 1 Quoted Machined by Norva Platics

syringe 1 User Selected Amtech

paste dispenser


coupler 1 Quoted Machined by Norva Platics

screw 1 Quoted Machined by Norva Platics

Quote: Plastics and Machining

30 Quoted $900 Norva Plastics

Cost $ 2,406.89 Mechanical Subsystem

Table 3: Mechanical Costs


120

7.2 Electrical Cost

Part Number Part Description Quantity Unit Price Total Cost

Y236653 Toroidal Transformer 250VA, 30V+30V 1 53.48 $ 53.48

193316 CAP ELECTROLYTIC 220uF 50V 10 0.0125 $ 0.13

1940272 POWER SUPPLY 12V @4.16A 1 26.95 $ 26.95

25604 HOOD, D-SUB METALIZED, 25 PIN 1 0.445 $ 0.45

1712616 PANEL MOUNT FUSEHOLDER 1 3.475 $ 3.48

16652 AC RECEPTACLE, MALE, 15A@250v 1 0.545 $ 0.55

494039 CONN,CPC AMPH 4 0.46875 $ 1.88

495162 CONN,CPC AMPH 4 0.28125 $ 1.13

495082 CONN,CPC AMPH 4 0.34875 $ 1.40

230050 CONN, MOLEX 1 0.225 $ 0.23

230041 CONN,MOLEX 1 0.195 $ 0.20

186992 SOLID-STATE RELAY 1 15.95 $ 15.95

175214 SOLID-STATE RELAY 1 6.95 $ 6.95

1953604 PLUG,DC,PWR,FEM 2.1 TO 2.5 1 1.49 $ 1.49

1953591 PLUG,DC,PWR,FEM 2.5 TO 2.1 1 1.49 $ 1.49

77586 STAND-OFF 5 0.029 $ 0.15

139222 STAND-OFF 5 0.045 $ 0.23

166546 STAND-OFF 2 0.1875 $ 0.38

133542 STAND-OFF 25 0.0078 $ 0.20

230958 USB 2.0 TYPE B CONNECTOR 1 0.475 $ 0.48

921651 USB TYPE A CONNECTOR 5 0.19 $ 0.95

2076252 TACTITLE SWITCH SURFACE MOUNT 10 0.0125 $ 0.13

2076682 DB9 FEMALE SHORT CONNECTOR 2 0.1625 $ 0.33

526504 TYPE III SNAP-IN CRIMP SOCKET 12 0.01875 $ 0.23

526563 TYPE III SNAP-IN CRIMP PLUG 12 0.01875 $ 0.23

IRF7341PBFCT-ND HEXFET 4.7A@25C,55V VDSS, 0.050 Ron 15 0.046 $ 0.69

768-1011-1-ND IC USB TO PARALLEL FIFO 28 SSOP FTDI 2 1.125 $ 2.25

751-1366-1 HIGH SPEED OPTO-COUPLER 15 0.070833 $ 1.06

160-1365-5-ND OPTO-ISOLATOR 8 0.06375 $ 0.51

PIC24FJ256GB110-I/PF-ND USB HOST MICRO CONTROLLER 1 4.43 $ 4.43

ENC624J600-I/PT-ND ETHERNET 10/100 CONTROLLER 1 2.47 $ 2.47

PIC24HJ256GP610-I/PF-ND PIC24 MICRO CONTROLLER 1 4.76 $ 4.76

PIC24HJ32GP302-I/SO-ND PIC24 MICRO CONTROLLER 1 2.41 $ 2.41

296-13094-1-ND RS-232 TRANSCIEVER 3 0.25 $ 0.75

620-1166-1-ND IC DRIVER MICROSTEPPING 38-TSSOP 3 1.656667 $ 4.97

GBJ2001-FDI-ND BRIDGE RECTIFIER, 100VRB 20A 1 1.76 $ 1.76

507-1442-ND CONN, MAGJACK 10/100B-TX 1 1.56 $ 1.56

706-1035-ND IC SRAM 4MBIT 10NS 44-TSOP 2 1.715 $ 3.43


121

576-1137-ND LDO REGULATOR 5.0V 1.25A 4 0.27875 $ 1.12

MCP1826S-3302E/DB-ND LDO REGULATOR 3.3V SOT223-3 7 0.082857 $ 0.58

MFU08051.25CT-ND FUSE 1.25A FAST BLOW 5 0.0407 $ 0.20

568-3309-1-ND VOLTAGE REG 5V 100MA SOT-223 1 0.855 $ 0.86

122-1376-ND IC CPLD 3.2K 144MCELL 100-TQFP 1 6.5 $ 6.50

P10.0CCT-ND 10.0 OHM 1/8W 1% 0805 5 0.0091 $ 0.05

P100AACT-ND 100 OHM 1/2W 5% 1210 5 0.0378 $ 0.19

P100ACT-ND 100 OHM 1/8W 5% 0805 5 0.0077 $ 0.04

P100KACT-ND 100K 1/8W 5% 0805 5 0.0077 $ 0.04

RMCF1/1010KJRCT-ND 10K 1/8W 5% 0805 50 0.000088 $ 0.00

P12KACT-ND 12K 1/8W 5% 0805 25 0.000828 $ 0.02

RHM180ARCT-ND 180 1/8W 5% 0805 5 0.0034 $ 0.02

RHM270ACT-ND 270 1/8W 5% 0805 10 0.004 $ 0.04

P2.0KACT-ND 2.0K 1/8W 5% 0805 5 0.0077 $ 0.04

P4.7KACT-ND 4.7K 1/8W 5% 0805 5 0.0077 $ 0.04

P470ACT-ND 470 1/8W 5% 0805 5 0.0077 $ 0.04

541-47KACT-ND 47K 1/8W 5% 0805 10 0.00385 $ 0.04

P49.9CCT-ND 49.9 1/8W 1% 0805 5 0.0091 $ 0.05

P49.9KCCT-ND 49.9K 1/8W 1% 0805 10 0.00455 $ 0.05

P1.0MACT-ND 1M 1/8W 5% 0805 5 0.0077 $ 0.04

P12.7KCCT-ND 12.7K 1/8W 1% 0805 5 0.0091 $ 0.05

T93YA-100-ND 100 OHM POT, 21 TURN 3 0.283333 $ 0.85

T93YA-2.0K-ND 2.0K OHM POT , 21 TURN 3 0.283333 $ 0.85

P12.4KCCT-ND 12.4K 1/8W 1% 0805 5 0.0091 $ 0.05

490-1683-1-ND 0.1uF 16V CERAMIC CAP 0805 250 5.55E-05 $ 0.01

490-1746-1-ND 10uF 6.3V CERAMIC CAP 0805 10 0.0082 $ 0.08

PCC270CGCT-ND 27pF 50V CERAMIC 0805 5 0.0151 $ 0.08

490-1638-1-ND 6.8nF 50V 5% CERAMIC 0805 5 0.0283 $ 0.14

399-1136-1-ND 1nF 50V CERAMIC 0805 10 0.0036 $ 0.04

445-3463-1-ND 1.0uF 50V 0805 CERAMIC 5 0.0099 $ 0.05

445-5206-1-ND 1.0uF 100V 0805 5 0.066 $ 0.33

511-1443-1-ND 4.7uF 6.3V TANT 0805 5 0.066 $ 0.33

490-1729-1-ND 0.33uF 25V CERAMIC 0805 15 0.007267 $ 0.11

709-1172-1-ND 22pF 50V CERAMIC 0805 5 0.0044 $ 0.02

535-9640-1-ND CRYSTAL 25.000MHZ 18pF 1 0.64 $ 0.64

XC1526CT-ND CRYSTAL 8.000 MHZ 20pF 1 0.585 $ 0.59

CTX736CT-ND OSC CLOCK 10.000 MHZ 1 3.675 $ 3.68

L62701CT-ND LED RED 5 0.0267 $ 0.13

SC237-ND CONN, POWERJACK MINI R/A PCMT 2.5MM 1 0.72 $ 0.72

296-5108-1-ND QUAD 2-INPUT AND GATE 14-SOIC 2 0.125 $ 0.25


122

160-1423-1-ND LED GREEN 5 0.0105 $ 0.05

277-1273-ND TERM BLOCK 2.54MM 2POS 1 0.545 $ 0.55

277-1274-ND TERM BLOCK 2.54MM 3POS 1 0.825 $ 0.83

A98335-ND TERM BLOCK 2.54MM 4POS 14 0.041786 $ 0.59

A98337-ND TERM BLOCK 2.54MM 6POS 5 0.1755 $ 0.88

LM1084IS-5.0-ND POSITIVE VOLTAGE REG 5V 5A 1 1.665 $ 1.67

160-1427-1-ND LED SUPER RED 0805 5 0.0126 $ 0.06

609-3464-ND LIST 0.100 5 0.02 $ 0.10

609-3469-ND LIST 0.100 5 0.048 $ 0.24

609-3248-ND LIST 0.100 5 0.06 $ 0.30

609-3256-ND LIST 0.100 3 0.071667 $ 0.22

3M9450-ND HEADER 5 POS 5 0.0204 $ 0.10

MHC10E-ND HEADER 10 POS 5 0.188 $ 0.94

576-1137-ND LDO REG 1.25A 5.0V TO263 3 0.371667 $ 1.12

399-4630-1-ND 4.7uF 25V TANT 7 0.034286 $ 0.24

495-2269-1-ND 1.0uF 25V TANT 20 0.003375 $ 0.07

BAV16W-FDICT-ND DIODE SWITCH 75V SOD123 35 0.008543 $ 0.30

399-1161-1-ND 15nF 50V CERAMIC 0805 10 0.0023 $ 0.02

PCC2452CT-ND 0.1uF 50V CERAMIC 0805 5 0.0103 $ 0.05

F1450CT-ND FUSE 0.125 125V FAST BLOW 1206 10 0.0371 $ 0.37

LM337IMPCT-ND NEGATIVE VOLTAGE REGULATOR 5 0.42 $ 2.10

296-12602-1-ND ADJUSTABLE POSITIVE REGULATOR LM317 5 0.176 $ 0.88

MB110S-TPMSCT-ND DIODE BRIDGE 1A 100V 5 0.112 $ 0.56

MT2119-ND TRANSFORMER DUAL 14VAC 0.40A 1 4.125 $ 4.13

P1.15KCCT-ND 1.15K 1/8W 1% 0805 15 0.003033 $ 0.05

541-0.0ACT-ND 0.0 OHM 1/8W 5% 0805 25 0.000828 $ 0.02

RHM20.0KCRCT-ND 20.0K 1/8W 1% 0805 15 0.001267 $ 0.02

RMCF1/1010KJRCT-ND 10K 1/8W 5% 0805 10 0.00105 $ 0.01

RHM1.00KCRCT-ND 1.00K 1/8W 1% 0805 10 0.0019 $ 0.02

RR12P4.32KDCT-ND 4.32K 1/10W 0.5% 0805 5 0.0148 $ 0.07

P240DACT-ND 240 1/8W 0.1% 0805 5 0.0204 $ 0.10

RHM2.05KCRCT-ND 2.05K 1/8W 1% 0805 25 0.000536 $ 0.01

PRL1632.043FCT-ND 0.043 OHM 1W 1% 1206 12 0.038417 $ 0.46

S9172-ND HEADER 20POS 5 0.037 $ 0.19

609-3464-ND LIST 0.100 10 0.01 $ 0.10

A98359-ND TERM BLOCK 5.08 2POS 3 0.141667 $ 0.43

495-1565-1-ND 10uF 25V TANT 3 0.115 $ 0.35

399-1168-1-ND 0.1uF 25V CERAMIC 0805 25 0.0009 $ 0.02

445-5102-1-ND 15nF 25V CERAMIC 0603 15 0.0013 $ 0.02

490-3895-1-ND 1uF 25V CERAMIC 0603 5 0.0068 $ 0.03


123

587-2400-1-ND 1.0uF 50V CERAMIC 0603 5 0.0165 $ 0.08

445-1314-1-ND 0.1uF 50V CERAMIC 0603 30 0.000917 $ 0.03

490-1731-1-ND 1.0uF 25V CERAMIC 0805 5 0.0081 $ 0.04

497-1314-1-ND IC GATE AND DUAL 2-INPUT SOT23-8 1 0.29 $ 0.29

160-1422-1-ND LED RED 0805 5 0.0105 $ 0.05

DMP2160UWDICT-ND MOSFET P-CH 20V 1.5A SOT-323 15 0.022 $ 0.33

2N7002W-FDICT-ND MOSFET N-CH 60V 115mA SOT 323 2 0.155 $ 0.31

OP27GSZ-ND IC OPAMP GP 8MHZ PREC 8SOIC 3 0.458333 $ 1.37

RMCF1/100RCT-ND 0.0 OHM 1/8W 0805 50 0.000088 $ 0.00

P4.99KCCT-ND 4.99K 1/8W 1% 0805 5 0.0091 $ 0.05

RR12P4.02KDCT-ND 4.02K 1/10W 0.5% 0805 5 0.0148 $ 0.07

P3.0MACT-ND 3M 1/8W 5% 0805 5 0.0077 $ 0.04

P46.4KCCT-ND 46.6K 1/8W 1% 0805 5 0.0091 $ 0.05

P26.1KCCT-ND 26.1K 1/8W 1% 0805 5 0.0091 $ 0.05

P2.00KCCT-ND 2.00K 1/8W 1% 0805 5 0.0091 $ 0.05

P1.00KCCT-ND 1.00K 1/8W 1% 0805 10 0.00455 $ 0.05

P1.0DDKR-ND 1.0 OHM 1/8W 1% 0805 5 0.091 $ 0.46

MCT0603-10K-MDCT-ND 10K 0.15W 0.5% 0603 5 0.0178 $ 0.09

311-3.57MCRCT-ND 3.57M 1/8W 1% 0805 5 0.0074 $ 0.04

P1.50KCCT-ND 1.50K 1/8W 1% 0805 5 0.0091 $ 0.05

RHM22.1KCCT-ND 22.1K 1/8W 1% 0805 5 0.0041 $ 0.02

LT1910IS8#PBF-ND IC MOSFET DRIVER HI-SIDE 8-SOIC 1 2.25 $ 2.25

455-1903-ND CONN HOUSING 2POS 2.5MM 15 0.001967 $ 0.03

455-2050-1-ND CONN CONTACT XA 26-22AWG TIN 25 0.00048 $ 0.01

296-13097-1-ND IC DRVR/RCVR MULTCH RS232 16SSOP 5 0.49 $ 2.45

296-13261-1-ND IC DUAL INVERTER GATE SOT-23-6 1 0.33 $ 0.33

40-2-5-ND SOLDER-WICK LEAD-FREE 5' 0.06" 1 4.08 $ 4.08

C2103L-100-ND HOOK-UP WIRE BLUE STRANDED 18AWG 1 24 $ 24.00

Uoled160g1 Serial OLED Graphics Display 1 79 $ 79.00

863-74FST3257DR2G QUAD 2:1 MULT 1 0.39 $ 0.39

31M9297 22000uF 63V ELECTROLYTIC CAPACITOR 3 3.863333 $ 11.59

IRF7341PBF HEXFET 55V 4.7A 25 0.00922 $ 0.23

Shipping

ADVANCED CIRCUITS $ 25.28




AMAZON $ 8.62

MOUSER $ 7.68


124

DIGIKEY $ 8.37

DIGIKEY $ 11.60

DIGIKEY $ 17.10

DIGIKEY $ 13.28

DIGIKEY $ 7.81

JAMECO $ 20.50

JAMECO $ 6.90

JAMECO $ 6.90

MOTION DRIVER BOARD 1 44.246 $ 44.25

MOTION DRIVER BOARD MODIFIED 1 56.97 $ 56.97

MAIN CONTROLLER BOARD 1 33 $ 33.00

PENDENT CONTROLLER BOARD 1 33 $ 33.00

Poster Board $ 8.00

Poster Paper $ 26.00

$ 53.48

Total Cost $ 779.76

Table 4: Electrical and Miscellaneous Costs

8. Implementation Schedule If one wanted to recreate the CNC Machine prototype built during this project a detailed implementation schedule should be followed. If the build were to be undertaken starting June 1, 2010, within the first week retrieve all the items found in table 3-1: prototype item/cost breakdown. Start the actual build the following week, January 7, 2010. The construction is relatively simple and can be easily completed in a week with a small team. Once all parts are gathered the build can be done within a 4 hour period with a three man team. Having three sets of arms helps greatly in the complete assembly/adjustment process. One guy can hold a part, with another stabilizing the other side of the CNC, while the other person connects parts or makes an adjustment. The prototype should be fully functional within hours of completion.

Step # Step Description Hours

1 Place parts on boards 4

2 Table Assembly 20

3 Gantry Assembly 15

4 Tapping and Drilling 13

5 Electric Box Assembly 8


125

6 Assemble Systems 4

7 Testing 5

Total Hours 69

9. APPENDIX A

9.1 VGA Data Sheet

The VGA port code is designed just like the pendent LCD Screen. The

commands code is placed in a buffer to be called. The buffer the VGA uses is the

VGABuffer[255] and a VGACount. This buffer will hold the command ID and the

sequence it needs to perform the function. The VGA chip has a pixel range from 0-

639 on the X axis and 0-479 on the Y axis. It also has a range of 0-79 columns and

0-39 rows. The code pixel placement is split up into 8bits, the MSB (Most

Significant Bit) and the LSB (Least Significant Bit).These bits will determine the X

and Y on the VGA screen. The VGA has 16 functions that were used to implement

the actions of the CNC. These functions are:

MoveTo()

EraseScreen()

SetBackground()

DrawLine()

SetFontSize()

DrawBox()

OpaqueTransparent()

PlaceText()

WriteString()

DisplayImage()

PaintArea()

DrawCircle()

SetColumn()

SetRow()

SetRowColumn()

PlaceCharUnFor()


126

A select number of theses functions are staticly implemented in the VGA chip.

These functions will use the VGABuffer[ ] and the VGACount to get total

functionality. Each line of implementation will go into its own array slot. The

Command ID will go in the VGABuffer[0] slot and the other lines of code will

follow behind in order as the data sheet requires.

9.1.1 MoveTo()

The MoveTo command takes the X and Y axis specified by the developer

and places the next point to the specified pixel point. The code takes the MSB and

the LSB of the Y and X axis and it gives the desired location.

9.1.2 EraseScreen

The EraseScreen function is a internal command on the VGA chip. This

function uses the VGABuffer. The command value for this function is 45hex. This

function will erase the screen and another function can be called to the VGA.

9.1.3 SetBackground()

This function will set the background color for the VGA screen. The

command value for the background is 42Hex. The next position atVGABuffer[1] is

the color of the background. The count of this function is then placed at 2.

9.1.4 DrawLine()

This function will draw a line on the screen from the current pixel position

to the next position. The functions command ID is 4Hex. In the array positions 1-4

the current positions of the CNC are placed here and for the positions 5-8 the

next positions are placed here all in pixel positions. At VGABuffer[9] the color of

the line is placed here. The count of this function is 10. Also at the end of these

functions the CurrentPosition is placed as the next X and Y positions.


127

9.1.5 SetFontSize()

This function sets the font size. The command ID of this functions is 46Hex.

In the VGABuffer[1] the Font size is added. The VGACount is equal to 2

9.1.6 DrawBox()

In this functions it doesn’t use the buffer or the counter. This functions draws a

box that will be used for the X,Y,Z,A, limit switches, and the state box. This

function is created by taking the current position and moving one position at a

time till it loops back. So the sequence that it takes is Current X and Current Y,

Current X to Y, X to Y, X to Current Y, and then back to Current X and Current Y.

9.1.7 OpaqueTransparent()

This function will be implamented when the firmware for the VGA allows

the user to open up documents from the USB to go on the VGA. This function can

make the text be Opaque or Transparent depending on the position the selector

is on. The Command ID for this is 4FHex. The next position in the buffer is the

mode that is wanted. If it is 01 it will be Opaque and if it is 01 it will be

transparent. The Counter for this will be 2.

9.1.8 PlaceText()

This function will place a text on the screen at the Row and Column position

desired by the screen developer. The command ID for this function is 54Hex. The

next position is where the character that is being written is placed. The next 2

positions is where you place the Column first and the Row second. The final

position in this array VGABuffer[4] is going to be the font color. The Counter of

this function will be 5.

9.1.9 WriteString()

This function writes a string on the VGA. The command ID for this function

is 73Hex. The next position of the array will be how it will be aligned on the VGA.

The next 2 positions will be first The Column and then the Row. The next position


128

will be the font color and then the characters that are being written on the screen

will be in the next position. The final position which is VGABuffer[6] is the

terminate command. This ends the string when strings are finished being wrote.

The counter on this function is 7.

9.1.10 DisplayImage()

This function will place an image on the screen. This function will be

implemented when the user functionality is working. This functions command ID

is 49Hex. The next 4 positions will be the X and Y pixel positions. The next 4

positions after that is first the width(MSB, LSB) and the height(MSB, LSB). The

final position will be the File that is going to be passed to the VGA. The count of

this will be 10.

9.1.11 PaintArea()

This function’s main task is to paint the area of a specific place.

The command ID of this function is 70Hex. The next 8 positions are the

current X and current Y positions and then the new X and Y positions all

in pixel format. The Final array position is the Color of the area.

9.1.12 DrawCircle()

This function takes the radius and the current position of the CNC and

makes a circle from that point. The command ID for this function is 43Hex. The

next 4 positions on the array are the current positions of X and Y. The next

position will be the radius. The radius in this function is measured in pixels. The

last position on the array is the graphic color. The buffer count in this function is 7

9.1.13 SetColumn()

This function’s main task is to set the current column position to a new

column that has been specified by the developer.


129

9.1.14 SetRow()

This function’s main task is to set the current row position to a new position

that is specified by the developer.

9.1.15 SetRowColumn()

This function’s main task is to set the current column and row at the same

time. This function allows it to be easier and quicker to set the row and column

without having to call 2 separate functions.

9.1.16 PlaceCharUnFor()

This function places a char in an unformatted state. Instead of it being

placed in a row and column it is placed by the X and Y pixel position. The

command ID for this function is 74Hex. The next array position is the Character

that is being entered. The next 4 positions are the X and Y positions. The next 2

array positions are the width and height. If these positions equal 01hex then the

sizes are normal, if they are 02hex then the sizes have doubled. If the hex number

increases to another number the VGA takes that number and multiplies it with

the normal character size. (Ex 10Hex = 3*normal)

9.2 3.1 Screens

There is only one screen that is implemented in this first version of the CNC.

This screen is the Main routing screen. This screen has the X,Y,Z,A, limit switches,

and the current state. Figure 3.1 shows what the VGA’s current screen will look

like.

X:

Y:

Z:

A:


130

Figure 3.1

The X, Y, Z, and A positions are made using write string and the boxes are used

using the Draw Box function. Inside of these boxes is the WriteToString function

that was implemented into the hand pendent. This will change the integer value

for X, Y, Z, and A into a string of characters. The box with the 5 circles in them is

the limit switches. These will turn red or green depending if it is on or off. The

final 2 boxes on the right side are the current state and the offset display. The top

box will show the offset of the CNC and the bottom box will tell if the machine is

in Jog, Idle, or Rapid state. The bottom opening will be a dialog box that will show

which commands were being called to the CNC.

10. APPENDIX B

10.1 X-axis

Table 10-1

Diam I F1 F2

Force

(per bearing) F(per rod)

0.75 0.0155 -0.00031 -0.000020 3.1 6.1

E 29000000 0.80 0.0201 -0.00024 -0.000016 4.0 7.9

y(deflection) -0.001 0.85 0.0256 -0.00019 -0.000012 5.1 10.1

x 15 0.90 0.0322 -0.00015 -0.000010 6.4 12.7

a1 13.6875 0.95 0.0400 -0.00012 -0.000008 7.9 15.8

b1 16.3125 1.00 0.0491 -0.00010 -0.000006 9.7 19.4

a2 16.3125 1.05 0.0597 -0.00008 -0.000005 11.8 23.6

b2 13.6875 1.10 0.0719 -0.00007 -0.000004 14.2 28.4

L 30 1.15 0.0859 -0.00006 -0.000004 17.0 33.9

1.18 0.0955 -0.00005 -0.000003 18.9 37.8

Forces Separation 1.3125 1.20 0.1018 -0.00005 -0.000003 20.1 40.2

1.25 0.1198 -0.00004 -0.000003 23.7 47.4


131

10.2 Y-axis Table 10-2

Diam I F1 F2

Force

(per bearing) F (per rod)

E 29000000 0.75 0.0155 -0.00063 -0.000033 1.5 3.0

y(deflection) -0.001 0.80 0.0201 -0.00048 -0.000025 2.0 3.9

x 19 0.85 0.0256 -0.00038 -0.000020 2.5 5.0

a1 17.6875 0.90 0.0322 -0.00030 -0.000016 3.1 6.3

b1 20.3125 0.95 0.0400 -0.00024 -0.000013 3.9 7.8

a2 20.3125 1.00 0.0491 -0.00020 -0.000010 4.8 9.6

b2 17.6875 1.05 0.0597 -0.00016 -0.000009 5.8 11.7

L 38 1.10 0.0719 -0.00014 -0.000007 7.0 14.0

1.15 0.0859 -0.00011 -0.000006 8.4 16.8

Forces Separation 1.3125 1.20 0.1018 -0.00010 -0.000005 9.9 19.9

1.25 0.1198 -0.00008 -0.000004 11.7 23.4

It was determined that a supported rail was needed.

10.3 Calculated Moments and Equivalent Force Couples on X Rails Table 10-3

Part quantity

Position from

Center of

Ballscrew

Horizontal

Spacing

between

the rails (in)

Weight/

Reaction Force

(lb)

Moment (lb-

in)

Volume

(in3)

Density

(lb/in3) Material

Force in y

on top

rails

zback 1 3.3627 4 1.068 3.590 31.403 0.034 HDPE 24.566

zbottom 1 4.5502 0.125 0.570 3.687 0.034 HDPE

zsides 2 4.5502 0.871 7.926 12.808 0.034 HDPE 21.954

zversa mount rails 3 3.7052 1.941 21.572 2.327 0.278 Steel

ztravel block 1 5.6127 0.598 3.359 17.602 0.034 HDPE

Tool Head 1 7.1877 10.000 71.877

z top front 1 4.5502 0.125 0.570 3.687 0.034 HDPE

SUM 98.641

zmotor & ztop rear 1 -0.357 1.771 -0.632 7.969 0.034 HDPE

ztop middle 1 2.393 0.106 0.254 3.125 0.034 HDPE

counterweight -3.482 3.000 -10.446


132

Table 10-4

Total vertical

gantry distance

Distance:

top rail-

tool head

Vertical

Spacing

between the

rails

Tool head

cutting

force

Moment of

tool head Force in x

Force in x

per rail

17.009 15.584 4.00 5.5 74.711 18.678 9.339

3.75 75.398 20.106 10.053

4.00 74.711 18.678 9.339

4.25 74.023 17.417 8.709

4.50 73.336 16.297 8.148

4.75 72.648 15.294 7.647

7.00 66.461 9.494 4.747

Table 10-5

Rail

front top

front bottom

back top

if 4 rails

20.534

20.796

13.070

no counterbalance

Forces per rail

11.652

16.775

19.935

11.652

w/ counterbalance

13.070


133

10.4 Trade off Study: 3 rods vs 4 rods, Rod Spacing

10.4.1 3 Rod Configuration Table 10-6

Trial 1 Trial 2 Trial 3 Trial 4

Moment due to Weight 100 100 100 100

Separation of 1&2 (x) 3.464 4 5 4

F1 28.87 25 20 25

Moment due to Cutting 75 75 75 75

Separation of 2&3 (y) 2.009 2.5 3 4

F2 37.33 30 25 18.75

Rod 1

F1 28.87 25.00 20.00 25.00

F2/2 18.67 15.00 12.50 9.38

Resultant 1 34.38 29.15 23.58 26.70

Rod 2

F1/2 14.43 12.50 10.00 12.50

F2/2 18.67 15.00 12.50 9.38

Resultant 2 23.60 19.53 16.01 15.63

Rod 3

F1/2 14.43 12.50 10.00 12.50

F2 37.33 30.00 25.00 18.75

Resultant 3 40.03 32.50 26.93 22.53


134

Table 10-7

1 2

3

rod orientation

34.38 23.60 29.15 19.53 23.58 16.01 26.70 15.63

40.03 32.50 26.93 22.53

Resultants, Trial 1 Resultants, Trial 2 Resultants, Trial 3 Resultants, Trial 4

y y y y

x

y

x x x x


135

10.4.2 4 Rod Configuration Table 10-8

Trial 1 Trial 2 Trial 3 Trial 4

Moment due to Weight 100 100 100 100

Separation of 1&2,3&4 (x) 3.464 4 5 4

F1 28.87 25 20 25

Moment due to Cutting 75 75 75 75

Separation of 2&3, 1&4 (y) 2.009 2.5 3 4

F2 37.33 30 25 18.8

Rod 1

F1/2 14.43 12.50 10.00 12.50

F2/2 18.67 15.00 12.50 9.38

Resultant 1 23.60 19.53 16.01 15.63

Rod 2

F1/2 14.43 12.50 10.00 12.50

F2/2 18.67 15.00 12.50 9.38

Resultant 2 23.60 19.53 16.01 15.63

Rod 3

F1/2 14.43 12.50 10.00 12.50

F2/2 18.67 15.00 12.50 9.38

Resultant 3 23.60 19.53 16.01 15.63

Rod 4

F1/2 14.43 12.50 10.00 12.50

F2/2 18.67 15.00 12.50 9.38

Resultant 4 23.60 19.53 16.01 15.63


136

Table 10-9

1 2

4 3

rod orientation

23.60 23.60 19.53 19.53 16.01 16.01 15.63 15.63

23.60 23.60 19.53 19.53 16.01 16.01 15.63 15.63

Resultants, Trial 1 Resultants, Trial 2 Resultants, Trial 3 Resultants, Trial 4

x

x

y y y

y

x

y

x x

10.5 Table Top Support Calculations

10.5.1 Table Support Calculations Table 10-10

E 29000000 Base Height 2 Point Forces F(per rail)

y(deflection) -0.001 0.25 0.500 0.3 0.5

x 19 0.25 0.625 0.5 1.0

a1 17.6875 0.25 0.750 0.9 1.7

b1 20.3125 0.25 0.875 1.4 2.7

a2 20.3125 0.25 1.000 2.0 4.1

b2 17.6875 0.25 1.125 2.9 5.8

L 38 0.25 1.250 4.0 8.0

Forces Separation 1.3125 0.375 0.500 0.4 0.8

0.375 0.625 0.7 1.5

0.375 0.750 1.3 2.6

0.375 0.875 2.0 4.1

0.375 1.000 3.1 6.1

0.375 1.125 4.3 8.7

0.375 1.250 6.0 11.9

0.500 0.500 0.5 1.0

0.500 0.625 1.0 2.0

0.500 0.750 1.7 3.4

0.500 0.875 2.7 5.5

0.500 1.000 4.1 8.1

0.500 1.125 5.8 11.6

0.500 1.250 8.0 15.9


137

10.6 Ballscrew Calculations

10.6.1 Ballscrew Calculations Table 10-11

lead (in/rev) 0.2

major diameter 0.625

minor diameter 0.48

pitch diameter 0.5525

rpm 1200

velocity (in/min) 240

velocity (in/s) 4 6 8 10 12 14

acceleration (in/s2) 15 15 15 15 15 15

lead angle 0.115

Y-axis

weight 100

mass 0.259

Force to Accelerate (lb) 3.89 3.89 3.89 3.89 3.89 3.89

change in linear speed(ft/min) 20 30 40 50 60 70

time to accelerate 0.27 0.40 0.53 0.67 0.80 0.93

Acc Force to torque (oz.in) 2.199 2.199 2.199 2.199 2.199 2.199

Torque-Forward Drive (in.lb) 3.54

torque-Forward drive (oz.in) 56.59

Acceleration Torque

WK2=(1/8)WD

212.5

Static friction force 25

Coefficient of friciton 0.25

Mass*Acc 3.88

Force (lb) 28.9

Torque (oz.in) 16.3

Kinetic friction force 18.75

Coefficient of friciton 0.1875

Mass*Acc 0

Force (lb) 18.75

Torque (oz.in) 10.6

Acceleration

Constant velocity

only applicable if the weight is being lifted.


138

10.7 Cable Carrier

10.7.1 Cable Carrier Selection Table 10-12

# Wire OD Height, A Width, B in ft

Z 3 spindle 0.23 0.41 0.63 8.24 1.8524 2.91 9.63 0.8

paste dispensor 0.22 5.51

limit, paste 0.13

air brush Cost 17.6

sum 0.58

X 5 spindle 0.23 0.41 1.18 24.15 3.775 5.93 17.59 1.5


limit, paste 0.13

air brush Cost 42.2

z-motor 0.22

limit, z 0.13

sum 0.93

Y 7 spindle 0.23 0.41 1.18 31 5 7.85 21.01 1.8


limit, paste 0.13

air brush Cost 49.8

z-motor 0.22

limit, z 0.13

x-motor 0.22

limit, x 0.13

sum 1.15

Width per foot Brackets

0.63 10.66 6.96

0.79 11.43 7.89

1.18 13.73 8.58

Loop Length

(desired, min)

Costs

Cost Total

109.57

Cable carriers

TotalWires Interior A&B

Axis Travel

Available

Height

10.8 Solder Paste Dispenser

10.8.1 Equations

(5.1.1)


139

(5.1.2)

(5.1.3)

(5.1.4)

10.8.2 Solution: General Engineering Equation Table 10-13


140

10.8.3 Flow Locations Table 10-14

h1 3 2.9996 h3 0

L1 2.5 2.4996 L2 0.25 L3 0.5

v1 0.0004 v2 0.023 v3 1.918

d1 0.618 d2 0.082 d3 0.009 27, 0.009

A1 0.3000 A2 0.0053 A3 6.36E-05

Re1 1.3E-05 Re2 9.48742E-05 Re3 8.6E-04

L1/d1 4.04 L2/d2 3.05 L3/d3 55.56

f1 5 f2 5 f3 5

hf1 4.3E-09 hf2 1.1E-05 hf3 1.323

K1-2 0.49 K2-3 0.49 K3-O 1

d1/d2 7.537 d2/d1 9.111 d2/d1

h1-2 1.0E-10 h2-3 3.4E-07 h3-O 0.005

Point 1 Point 2 Point 3

Select

Dispensing

Needle

10.8.4 Solution: Force Approximation Table 10-15

Approximated Force Torque [oz.in]

6.05 3.208

5 2.7

10 5.3

15 8.0

20 10.6

10.9 Design Notebook: Pat Brokaw

10.9.1 Table of Contents

1. Reference websites

2. Deflection calculation solved for deflection

3. 1st team meeting notes

4. Mechanical literature review sections

5. 2nd team meeting notes

6. 3rd team meeting notes

7. Deflections: solved for force

8. Team meeting notes

9. Management meeting notes


11. Literature review notes: Drive mechanism


141

12. Literature review notes continued with references used



15. Mechanical subsystem proposal notes


17. Initial mechanical specifications

18. Initial electrical specifications

19. Microcontroller block diagram


21. Discussion notes: z-axis


23. List of forces and List of mechanical parts

24. Table end sketches, Calculations for table top support

25. Sketches: table bottom, y-cross, y-lift mounts

26. Notes on screw sizes

27. Dimensions for y-lifts, table top spacing, y-axis ballnut flange

28. Dimensions x-axis top and bottom

29. Blank

30. Blank

31. Moments and Forces on each x-axis rod

32. Deflection equation used to calculate rod deflections

33. Acceleration and force on x-axis, paste dispenser sketch

34. Paste dispenser sketches, paste dispenser motor dimensions, volume dispensed calculation

35. Z-axis sketch for small versa rails (unused), Volumetric thermal expansion calculation

36. Z-axis dimensions

37. Z-back dimensions, z-bottom dimensions

38. Z-top dimensions

39. Thrust bearing block dimensions, acceleration force(Roton equation)

40. Pendant case dimension

41. Pendant case sketch (unfinished)

42. Pendant case sketch with dimensions for board mounts

43. Z-mount dimensions

44. Dimensions: tool head mount plate, z-axis mounting

45. Cable carrier dimensions

46. Spindle mounting block

47. Equations for ballscrew calculations

48. Paste dispenser pressure calculations

49. Paste dispenser angular velocity and torque calculations

50. Transformer test voltages

51. Rectifier Heat Sink


142

52. Lecture notes for design report, April 6,


143

10.10 Cost Data and Schedule Data

10.10.1 Prototype Cost Table 10-16

Component Part # Quantity Cost Total Cost Source Date

Z axis

z ballscrew 24" $10.09/ft $ 20.18 Roton 1/24/2010

Ballnut 1 $ 23.55 $ 23.55 Roton 1/24/2010

thrust bearing

block z1 $ 11.75 $ 11.75

Stock from Online Metals,

machined in house

ball nut flange z 1 $ 3.38 $ 3.38 Stock from Online Metals,

machined in house

ztop 1 Donated Machined by Norva Platics

zside 2 Donated Machined by Norva Platics

zbottom 1 Donated Machined by Norva Platics

zback 1 Donated Machined by Norva Platics

zmount 1 $ 18.23 $ 18.23 Stock from Online Metals,

machined in house

standoff 2 $ 9.85 $ 9.85 Stock from McMaster Carr,

machined in house3/29/2010


versa guide block 2 $ 33.80 $ 67.60 Anaheim Automation 1/27/2010

Spindle Plate 1 $ 10.94 $ 10.94 Stock from McMaster Carr,


Spindle 1 On hand James Williams

spindle holder 1 Donated Stock from Norva Platics,

machined in house

X axis

thrust bearing

block1


machined in house

x-traveling block 1 $ 105.00 $ 105.00 Stock from Norva Platics,

machined in house

xback 1 Donated Machined by Norva Platics

Common stock listed

previously


144


145

xballscrew 36" $10.09/ft $ 30.27 Roton 1/24/2010

Ballnut 1 $ 23.55 $ 23.55 Roton 1/24/2010

xrods 3 $ 39.35 $ 118.05 Lintech

xtop 1 Donated Machined by Norva Platics

ball nut flange xStock from Online Metals,

machined in house

Bushings 6 $39.95/4 $ 79.90 VXB

Table

Table sides 2 Donated Machined by Norva Platics

Table Bottom 1 Donated Machined by Norva Platics

Table end -Motor 1 Donated Machined by Norva Platics

Table End 1 Donated Machined by Norva Platics

Table Top 1 Donated Machined by Norva Platics

Table supports 3 $ 8.69 $ 26.07 Stock from Online Metals 4/7/2010

Table stand rails 2 $ 10.62 $ 21.24 Stock from Online Metals 4/7/2010

Y axis

sides 1 Donate Machined by Norva Platics

side w/o motor 1 Donate Machined by Norva Platics

Ball flange y 1Stock from Online Metals,

machined in house

y-cross 1Stock from Online Metals,

machined in house

y support rail 1 $ 179.00 $ 179.00 VXB 1/28/2010

yballscrew 48" $10.09/ft $ 40.36 Roton 1/24/2010

Common stock listed

previously

Common stock listed

previously

Common stock listed

previously


146

Ballnut 1 $ 23.55 $ 23.55 Roton 1/24/2010

y-axis bushing

block2 $ 39.95 $ 79.90 VXB 1/28/2010

y-lifts 2 $ 57.33 $ 57.33 Stock from Online Metals,

machined in house

Common Parts

(X, Y, & Z)

Thrust Bearings 6 $14.95/2 $ 44.85 VXB

Ball Bearings 3 $ 5.55 $ 16.65 McMaster Carr 3/29/2010

Bearing seals 6 $ 2.31 $ 13.86 MSC Direct

Seal retainer 3 Donated Stock from ME shop,

machined in house





Wiring 20 ft 3 $ 13.00 $ 39.00 Anaheim Automation

Machine

Electronics

Cable Carriers

Cable Carrier

(X & Y)2 $ 41.19 $ 82.38 McMaster Carr 3/29/2010

Mounting

Brackets (X&Y)2 $ 8.58 $ 17.16 McMaster Carr 3/29/2010

Cable Carrier

(Z)1 $ 10.66 $ 10.66 McMaster Carr 3/29/2010

Mounting

Brackets (Z)1 $ 6.96 $ 6.96 McMaster Carr 3/29/2010

Electronics Case

Top 1 Donated Machined by Norva Platics


147

Bottom 1 Donated Machined by Norva Platics

Sides 2 Donated Machined by Norva Platics

Front 1 Donated Machined by Norva Platics

Back 1 Donated Machined by Norva Platics

Divider 1 Donated Machined by Norva Platics

Pendant Case

Case 1

Back Plate 1

Fasteners

M5x20 8 $5.34/25 $ 5.34 McMaster Carr 4/7/2010

M6x25mm 8 $7.91/25 $ 7.91 McMaster Carr 4/7/2010

4-40x0.25 24 On Hand James Williams

6-32x0.25 17 On Hand James Williams

8-32x0.375 2 Lowes

8-32x0.5 12 Lowes

8-32x1 68 Lowes

10-24x0.75 12 $7.94/100 $ 7.94 McMaster Carr

10-24x1 148 $16.15/100 $ 32.30 Fastenal 4/2/2010

1/4-20x1 77 $9.45/50 $ 18.90 McMaster Carr

3/8-16x1.5 10 $ 9.79 $ 9.79 Lowes

3/8-24x1 4 $8.27/25 $ 8.27 McMaster Carr 4/7/2010


148

8-32x0.25

(self tapping)4 Lowes

5/16-16 Nut 3 Donated ME Shop

board standoffs

6-32x0.3125 7On Hand James Williams



set screws

8-32x0.25 3Donated ME Shop

8-32x0.3125 1Donated ME Shop

grease zerk

1/8-27 PTF 3$2.90/10 $ 2.90 McMaster Carr

Tools, etc.

1/8" carbide

tipped drill bit 110.53$ $ 10.53 McMaster Carr

#12-5/16

extractor 12.39$ $ 2.39 McMaster Carr

15/16-16 tap 161.17$ $ 61.17 McMaster Carr

3/8-16 tap 116.02$ $ 16.02 McMaster Carr

Layout fluid 16.21$ $ 6.21 MSC Direct

Unused Aluminum 1 5.07$ 5.07$ Stock from Online Metals,

machined in house

Washers

Split Lock washers

#10 32 $2.13/100 $ 2.13 McMaster Carr

1/4 56 $5.64/100 $ 5.64 McMaster Carr


149

3/8 16 $4.00/25 $ 4.00 Lowes

M5 8 Lowes

M6 8 Lowes

Ext. Tooth Lock

washers

#10 110 $2.54/100 $ 5.08 Fastenal 4/16/2010

Flat washers

3/8 8 Lowes

.438x.203x.032 24

.500x.265x.032 36

Paste Dispenser

motor mount 1 Donated ME Shop

plate 1 $ 25.34 $ 25.34 Stock from Online Metals,

machined in house

plunger 1 Donated ME Shop

syringe 1 On hand James Williams, Amtech

paste dispenser 1 Donated ME Shop

coupler 1 Donated ME Shop

screw 1 Donated ME Shop

Shipping Totals

Norva Plastics $ 11.84 $ 11.84

Online Metals $ 36.87 $ 36.87

Anaheim

Automation $ - $ -

Lintech $ - $ -


150

VXB 2 $ 6.75 $ 13.50

Roton $ 21.02 $ 21.02

MSC 2 $ 10.98 $ 21.96

McMaster $ 14.50 $ 14.50


10.11 Manufacturing Costs and Schedule

10.11.1 Equipment Costs


151

Table 10-17

Equipment Cost Source Date Link

Design Tools

AutoCad Inventor 1,463.29$ Amazon 4/25/2010 http://www.amazon.com

Microsoft Office: Excel 409.95$ Newegg 4/25/2010 http://www.newegg.com

Machining and Assembly

Tools

Mill 5,995.00$ Penn Tool

Company4/25/2010 http://www.penntoolco.com

Lathe & Grinding Lathe 3,495.00$ Penn Tool

Company4/25/2010 http://www.penntoolco.com

Horizontal Bandsaw 1,149.00$ Grainger 4/25/2010 http://www.grainger.com

Vertical Bandsaw 2,075.00$ Grainger 4/25/2010 http://www.grainger.com

Drill Press 639.00$ Grainger 4/25/2010 http://www.grainger.com

Chop Saw 279.17$ Fastenal 4/25/2010 http://www.fastenal.com

Cordless Drill 185.28$ Fastenal 4/25/2010 http://www.fastenal.com

Combination Wrenches 50.54$ Fastenal 4/25/2010 http://www.fastenal.com

Allen Wrenches 13.29$ Fastenal 4/25/2010 http://www.fastenal.com

Screw drivers, both Phillips

and Flat head51.24$ Fastenal 4/25/2010 http://www.fastenal.com


152

Various endmills from 1/8-5/8 50.00$ Fastenal 4/25/2010 http://www.fastenal.com

Fly cutter and various milling

tool heads5.70$

Machine Shop

Discount Supply4/25/2010 http://www.msdiscount.com

Boring head 421.30$ Machine Shop

Discount Supply4/25/2010 http://www.msdiscount.com

Calipers 53.27$ Fastenal 4/25/2010 http://www.fastenal.com

Micrometers

0"-1" 16.40$ Fastenal 4/25/2010 http://www.fastenal.com

1"-2" 23.93$ Fastenal 4/25/2010 http://www.fastenal.com

Telescoping gauges 250.99$ Fastenal 4/25/2010 http://www.fastenal.com

Depth gauges 145.55$ McMaster Carr 4/25/2010 http://www.mcmaster.com

Tap and Die Set 106.98$ Fastenal 4/25/2010 http://www.fastenal.com

Tap handles

Taps: #4-40, #6-32, #8-32,

#10-24, 1/4-20, 3/8-16,

3/8-24, 1/8-27NPT; Die:

5/16-18 Drill bits:#43, #36, #32, #29,

#27, #25, #24, #18, #9, #7, F,

H, Q, W, X, 5/16”, ½”

#1-#60 Drill Set 89.99$ Fastenal 4/25/2010 http://www.fastenal.com

A-Z Drill Set 119.99$ Fastenal 4/25/2010 http://www.fastenal.com

Total Equipment Cost 17,090$


153

10.11.2 Material Costs Table 10-18


154

Component Part # Quantity Cost Total Cost SourceDate

Priced

Common Parts

(X, Y, & Z)

Ballscrews 108" $10.09/ft $ 90.81 Roton 1/24/2010

Ballnuts 3 $ 23.55 $ 70.65 Roton 1/24/2010

Thrust bearing

blocks3 $ 11.75 $ 11.75


machined in house

Ballnut flanges 3 $ 3.38 $ 3.38 Stock from Online Metals,

machined in house

Thrust Bearings 6 $14.95/2 $ 44.85 VXB

Grease Zerks: 1/8-

27 PTF3 $2.90/10 $ 2.90 McMaster Carr

Ball Bearings 3 $ 5.55 $ 16.65 McMaster Carr 3/29/2010

Bearing seals 6 $ 2.31 $ 13.86 MSC Direct

Seal retainer 3 $1.25/3 $ 1.25 Stock from ME shop,

machined in house





Wiring 20 ft 3 $ 13.00 $ 39.00 Anaheim Automation

Cable Carriers

Cable Carrier

(X & Y)2 $ 41.19 $ 82.38 McMaster Carr 3/29/2010

Mounting

Brackets (X&Y)2 $ 8.58 $ 17.16 McMaster Carr 3/29/2010

Cable Carrier

(Z)1 $ 10.66 $ 10.66 McMaster Carr 3/29/2010


155

Mounting

Brackets (Z)1 $ 6.96 $ 6.96 McMaster Carr 3/29/2010

Z axis

z-top 1 Quoted Machined by Norva Platics

z-side 2 Quoted Machined by Norva Platics

z-bottom 1 Quoted Machined by Norva Platics

z-back 1 Quoted Machined by Norva Platics

z-mount 1 $ 18.23 $ 3.04 Stock from Online Metals,

machined in house

standoff 2 $ 9.85 $ 9.85 Stock from McMaster Carr,



versa guide block 2 $ 33.80 $ 67.60 Anaheim Automation 1/27/2010

Spindle Plate 1 $ 10.94 $ 10.94 Stock from McMaster Carr,


Spindle 1 $ 22.00 $ 22.00 James Williams

spindle holder 1 Quoted Machined by Norva Platics

X axis

x-traveling block 1 $ 105.00 $ 105.00 Stock from Norva Platics,

machined in house

xback 1 Quoted Machined by Norva Platics

xtop 1 Quoted Machined by Norva Platics

x-rods 3 $ 39.35 $ 118.05 Lintech

x-bushings 6 $39.95/4 $ 59.93 VXB

Table

Table sides 2 Quoted Machined by Norva Platics

Table Bottom 1 Quoted Machined by Norva Platics


156

Table end -Motor 1 Quoted Machined by Norva Platics

Table End 1 Quoted Machined by Norva Platics

Table Top 1 Quoted Machined by Norva Platics

Table supports 3 $ 8.69 $ 26.07 Stock from Online Metals 4/7/2010

Table stand rails 2 $ 10.62 $ 21.24 Stock from Online Metals 4/7/2010

Y axis

sides 1 Quoted Machined by Norva Platics

side w/o motor 1 Quoted Machined by Norva Platics

y-cross 1 $ 18.23 $ 15.19 Stock from Online Metals,

machined in house

y support rail 1 $ 179.00 $ 179.00 VXB 1/28/2010

y-axis bushing

block2 $ 39.95 $ 79.90 VXB 1/28/2010

y-lifts 2 $ 57.33 $ 57.33 Stock from Online Metals,

machined in house

Machine

Electronics

Electronics Case

Top 1 Quoted Machined by Norva Platics

Bottom 1 Quoted Machined by Norva Platics

Sides 2 Quoted Machined by Norva Platics

Front 1 Quoted Machined by Norva Platics

Back 1 Quoted Machined by Norva Platics

Divider 1 Quoted Machined by Norva Platics

Pendant Case

Case 1 Quoted Machined by Norva Platics


157

Back Plate 1 Quoted Machined by Norva Platics

Fasteners

M5x20 8 $5.34/25 $ 1.71 McMaster Carr 4/7/2010

M6x25mm 8 $7.91/25 $ 2.53 McMaster Carr 4/7/2010

4-40x0.25 24

6-32x0.25 17

8-32x0.375 2

8-32x0.5 12

8-32x1 68

10-24x0.75 12 $7.94/100 $ 0.95 McMaster Carr

10-24x1 148 $16.15/100 $ 23.90 Fastenal 4/2/2010

1/4-20x1 77 $9.45/50 $ 14.55 McMaster Carr

3/8-16x1.5 10 $ 9.79 $ 9.79 Lowes

3/8-24x1 4 $8.27/25 $ 1.32 McMaster Carr 4/7/2010

8-32x0.25

(self tapping)4

5/16-16 Nut 3

board standoffs

6-32x0.3125 7

6-32x0.3125 10

4-40x0.25 4

set screws

8-32x0.25 3

8-32x0.3125 1


158

Washers

Split Lock washers

#10 32 $2.13/100 $ 0.68 McMaster Carr

1/4 56 $5.64/100 $ 3.16 McMaster Carr

3/8 16 $4.00/25 $ 2.56 Lowes

M5 8

M6 8

Ext. Tooth Lock

washers

#10 110 $2.54/100 $ 2.79 Fastenal 4/16/2010

Flat washers

3/8 8

.438x.203x.032 24

.500x.265x.032 36

Fastener Totals Unlisted $ 30.00 $ 30.00

Paste Dispenser

motor mount 1 Quoted Machined by Norva Platics

plate 1 $25.34/3 $ 8.45 Stock from Online Metals,

machined in house

plunger 1 Quoted Machined by Norva Platics

syringe 1 User Selected Amtech

paste dispenser 1 Quoted Machined by Norva Platics

coupler 1 Quoted Machined by Norva Platics

screw 1 Quoted Machined by Norva Platics

Quote: Plastics

and Machining30 Quoted $900 Norva Plastics



159

10.11.2.1 Recommended Vendors

Vendors recommended by the CNC machine design team include:

Roton, http://www.roton.com

o Ballscrews and Ballnuts

Lintech, http://www.lintechmotion.com

o X axis linear guide rods

Anaheim Automation, http://www.anaheimautomation.com

o Y-axis versa rails and blocks.

VXB, http://www.vxb.com

o Thrust bearings, x-rod bushings, y-axis supported rail and bushing blocks

MCMaster Carr, http://www.mcmaster.com

o Ball bearings, belts,

Online Metals, http://www.onlinemetals.com

o Metal stock

Norva Plastics, http://www.norvaplastics.com

o Plastics and machining of plastic components

MSC Direct, http://www.mscdirect.com

o Pulleys, bearing seals

Fastenal, http://www.fastenal.com

o Fasteners


160

10.11.3 Fasteners Table 10-19


161

Part Location/comment Fastener Size Quantity

Bolts Split Lock ET Lock Flat

table top 10-24x1 18 18

table supports 1/4-20x1 21

table ends 10-24x1 22 22

table sides bottom 10-24x1 26 26

ends 10-24x1 16 16

y-rails 10-24x1 28

y-sides, uprights connects lifts 1/4-20x1 24 24 24

x-rods 3/8-16x1.5 6 6 6

Holds aluminum

y-lifts bearing blocks M6x25mm 8 8

connects y-cross 1/4-20x1 12 12

x-back end 10-24x1 8 8

x-top 10-24x1 20 20

z-sides 8-32x1 16

z-top 8-32x1 4

z-bottom 8-32x1 4

X-Z mounts z-axis 3/8-16x1.5 4 4

versa rails 10-24x1 10 20

versa block M5x20mm 8 8

z-mount 3/8-24x1 4 4

spindle mount 3/8-16x3 2 2 2

thrust bearing block 1/4-20x1 12 12 12

ballnut flange 1/4-20x1 8 8

motor mounting 10-24x0.75 12 12 24

Electronics housing driver board mount 8-32x1 7

divider 8-32x1 5

top 8-32x1 8

bottom 8-32x1 24

sides 8-32x0.5 12

relay 8-32x0.375 2

motor connectors 4-40x0.25 16

db-25 outputs 4-40x0.25 4

AC-input 8-32x0.25 (self-tapping) 2

Fuse 8-32x0.25 (self-tapping) 2

driver standoffs 6-32x0.25 7

controller standoffs 6-32x0.25 10

vga standoffs 4-40x0.25 4

board standoffs driver 6-32x0.3125 7

main controller 6-32x0.3125 10

vga 4-40x0.25 4

set screws ballnuts 8-32x0.25 3

z-axis thrust bblock 8-32x0.3125 1

grease zerk bearing blocks 1/8-27 PTF 3

Washers


162

Table 10-20

Totals

Fasteners M5x20 8

M6x25mm 8

4-40x0.25 24

6-32x0.25 17

8-32x0.375 2

8-32x0.5 12

8-32x1 68

10-24x0.75 12

10-24x1 148

1/4-20x1 77

3/8-16x1.5 10

3/8-24x1 4

3/8-16x3 2

8-32x0.25 (self-tapping) 4

396

Split Lock washers #10 32

1/4 56

3/8 16

M5 8

M6 8

Ext. Tooth Lock washers #10 110

Flat washers 3/8 8

.438x.203x.032 24

.500x.265x.032 36


163

10.11.4 Component Data Sheets

Ballscrews

Versa rails

Versa blocks

X-rods

X-rod bushings

Y-Supported Rail

Y-Bushing Blocks

Ball Bearings

Thrust Bearings

Bearing Seals

Motors

Pulleys

Belts

Axis

Pulley

Diameter Max Min Middle Max Min Middle Order Price Source

Z 1.890 5.08 4.08 4.58 16.09 14.10 15.10

X 1.890 8.00 7.03 7.52 21.94 19.99 20.97

Y 1.890 4.50 3.50 4.00 14.94 12.94 13.94

-$ Total

Spacing Belt Length


164

10.11.4.1 Engineering Drawings

10.11.4.2 Z-axis

10.11.4.3 X-axis

10.11.4.4 Base

10.11.4.5 Y-axis

10.11.4.6 Tool Heads

10.11.4.7 Spindle

10.11.4.8 Paste Dispenser

10.11.4.9 Machine Electronics

10.11.4.10 Pendant Case

10.11.4.11 Electronic Component Housing


165

Part Name Part Number

1 Top

2 Bottom

3 Front

4 Back

5 Left Side

6 Right Side

7 Partition

8 Driver Board Panel

Electronic Component Housing Assembly, BB-5


166

11. APPENDIX C

11.1 Pendent Code Datasheet

11.1.1 Graphics Header File:

All graphics within the Graphics.c file uses an LCDBuffer[ ] array that has a

size of 255. Also it has a LCDCount that counts the number of positions used

within the LCDBuffer. Inside the main structure there three sets of internal

structures:

CurrentPos (Current Position)

PositionArray (Position in Rows and Columns)

Properties (Color, Font, etc)

In Current Position we have two declarations X and Y. These declared variables

have a data type int which will be used for pixel position on the LCD Screen. The

range of the Y position will be 72 pixels and the X position will be 120 Pixels. The

Position Array structure has two declarations Row and Column. Also declared as

int data types, will be used in positioning with Rows and Columns. Unlike the

current position we have a range of 9 Rows and 15 Columns.

In the Properties structure we have the six declared variables that have a data

type of int:

Color

FontSize

BackColor (background color)

CurrentScreen

Pen (Pen size)

The Color variable is used to set the color for any of the draw functions.

BackColor is used to set the background color inside the Graphics.c file. All Colors


167

are defined outside of the structure inside the Graphics.h file. These colors are

white, black, red, green, blue, yellow, teal, fuchsia, purple, gray, and orange.

These colors are called by using theses specified names:

clWhite = White

clBlack = Black

clRed = Red

clGreen = Green

clBlue = Blue

clYellow = Yellow

clTeal = Teal

clFuchsia = Fuchsia

clPurple = Purple

clGray = Gray

clOrange = Orange

FontSize is used to specify the character font sizes. There are 3 different font sizes

that can be used but it changes the Row and Column sizes.

FONT_SIZE_5X7

FONT_SIZE_8X8

FONT_SIZE_8X12

For the 5X7 the Rows will be 15 and the Columns will be 20, for the 8X8 the Rows

will be 15 and the Columns will be 15, and finally for the 8X12 which we will use

for our pendent we will have 9 Rows and 15 Columns. The current screen variable

will be useful to set up a command that will set what screen that we need to be

on at a specific time. The pen variable is used to set the pen size of the draw

functions. When the pen is set to be solid it will have a circle that is filled in. If the

pen is set to be wire it will just outline the shape and it won’t be filled in. We have

two defined pen sizes that can be used in our program:

SOLID


168

WIRE

Some more defined variables that will be used in our program are:

OPAQUE

TRANSPARENT

These are used to allow when we are choosing a window or command we can

make it OPAQUE so it looks like we are playing out selector over that selection

and it would become TRANSPARENT if we were not selected over the file box.

11.1.2 Graphics Source File:

In our Graphics.c file we have every function that will be shown on the

pendent LCD screen. Here are the list of commands in this file:

MoveTo()

WriteString()

DrawLine()

DrawBox()

DrawChar()

DrawCircle()

DrawTriangle()

RowColumnPos()

SetOpaqueTransparent()

SetBackgroundColor()

SetPenSize()

DrawSemiCircle()

ClearImage()

11.1.2.1 DrawIcon()


169

The first command is the MoveTo function. The MoveTo function takes the x and

y pixels and moves them to the next position. It then saves the position that you

move to as the current position.

EX: MoveTo(16,8); – 16 pixels in the X direction and 8 in the Y direction

The WriteString command is used to write a string of chars. It takes the string that

you write and puts it into an array and prints it onto the screen.

EX: WriteString(“Hello World”); - Prints Hello World on the LCD Screen

The DrawLine command as it specifies draws a line from the starting position to a

specified position.

EX: DrawLine(56, 20); – Draws a line from the current position to the pixel

position X = 56 and Y=20.

(X2,Y2)

(X1,Y1)

The DrawBox command draws a box using the current position as one corner and

then the users gives a position on the opposite corner.

EX:DrawBox(56,20); - In this figure X1 and Y1 are the current positions and

X2 = 56, Y2 = 20.

(X1,Y1)

(X2,Y2)


170

The DrawChar command returns a char but returns it one at a time in. It takes the

current row and column that you are in prints the char.

EX:DrawChar(A); - Writes a char “A” to the current position array and prints

it on the LCD Screen.

Draw Circle takes the Radius and the current positions and makes a complete loop

to create a circle. The radius of this command is in pixels

EX: DrawCircle(16); - Draws a Circle with a radius of 16 pixels

(Radius)

DrawTriangle takes 2 positions on the screen and the current pixel positions and

plots out a Triangle on the screen.

EX: DrawTriangle(36,12,45,18); - X1 and Y1 are the current positions and

X2,Y2,X3,Y3 are all calculated. In this example 36=X2, 12=Y2, 45=X3, 18=Y3.

(X1,Y1)

(X2,Y2) (X3,Y3)


171

RowColumnPos is similar to MoveTo but this command uses array positions and

not pixel positions. This command is used for any type of character format.

EX: RowColumnPos(4,5) – This sets the current position at Row 4 and

Column 5

SetOpaqueTransparent is used or the DrawBox command. This command will be

used to implement a file or window selected. It will be Opaque when selected and

Transparent when de-selected.

EX: SetOpaqueTransparent(OPAQUE)- this command will set the Box in the

function to be Opaque.

ExampleOpaque

ExampleTransparent

SetBackgroundColor will set the background color to any of the Colors that were

defined on the Graphics.h file.

EX: SetBackgroundColor(clBlue);- sets background color to Blue

SetPenSize sets the pen size of the drawing. This is used to either fill or not fill a

graphic

EX:SetPenSize(SOLID or WIRE); - sets a graphic to be filled or not filled


172

Wire

Solid

DrawSemiCircle creates a SemiCircle on the LCD Screen. This command was

created to draw a Semi-Circle for the Jog Screen. You need to give the radius of

the semi-circle to have it drawn.

Ex: DrawSemiCircle(12); - Draws a Semi-Circle with the radius of 12 pixels

(Radius)

ClearScreen clears the screen of any currently displayed information. This

command is used to clear the screen when the jump file screen is being uploaded

from the main sub screen.

DrawIcon is used after an icon is uploaded into the processor after initialization to

illustrate either a folder or file for the jump file screen to display the drive’s

directory

Ex: DrawIcon(Folder); -Draws the folder icon before the folder name

**

11.1.3 Screens Header File:

This header file is used for all external declared variables for the Screens.c

source code. There are 5 external variable that are declared: X, Y, Z, A, Buffer[6].

The X Variable is used for the X axis on the CNC, the Y is used for the Y axis of the

CNC, the Z is used for the Z axis of the CNC, and the A is used for the acceleration

of the CNC itself. The Buffer[6] array will be used to transfer a int to a string .


173

Structures:

These are structures built within the screen header file to be used as a

new type such as integer, string, or character for the purpose of collecting

particular information from the microcontroller and sending it to the

pendant.

TPosition

Structure built with the ability to hold the information from all four

axes (X, Y, Z, A). It gives the user the ability to access any axis’

dimension after it stops on the table.

TIP

Structure gives the user the ability to access addressing information

incoming from the Ethernet connection and break down into smaller

amounts of information.

TMachineParameters

Structure gives the user the ability to collect information based upon

the user’s particular job it is currently running such as jog rates, feed

rates, speed rates, and acceleration/deceleration.

TTCPIPConfiguration

Structures uses the TIP structure discussed above to set up the

incoming information received through Ethernet into the form

xxx.xxx.xxx.xxx where the TIP structure breaks it down into four

pieces of information to be displayed in the correct form.


174

11.1.4 Screens C Source file:

This souce file is the Main source file that will talk to the Pendent.C code.

This file will have the main drawing files and functionality files. The commands in

this file are:

DrawMainScreen()

DrawMainSubScreen()

DrawOffsetSubScreen()

DrawParametersSubScreen()

DrawSoftLimitsSubScreen()

DrawOffsetScreen()

DrawMachineParameters ()

DrawSoftLimits()

DrawTCPIPConfiguration()

DrawComPort()

DrawFileScreen()

DrawFileScreen()

The DrawMainScreen command will draw our main pendent screen. At the top

left of the screen will display the X, Y, and Z coordinates on the CNC and the

Acceleration speed which is denoted as A on the screen. At the bottom left of

the screen is a 5 limit switch section that is set using circles. When a circle is

red that limit is turned off and when it is green it is turned on. At the top right

there will be a Jog switch dial that can be changed by the user, and at the

bottom right of the screen is the display screen that will tell if the CNC is

Running(RUN), Jogging(JOG), or Idle(IDLE).


175

X:

Y:

Z:

A:

JOG

-50 50

The DrawMainSubScreen command is the transition screen from the main

screen to all the lower sub-screens. The title will state “Subscreens” followed

below by a drawn line and the five different sets of sub-screens which are

offsets, parameters, soft limits, and thumb drive.

Subscreens

- Offsets

- Parameters

- Soft Limits

- Thumb Drive


176

The DrawOffsetsSubScreen command can be chosen from the main sub-

screens menu. It gives the user the ability to choose between the offsets

between the different offsets of home position, park position, work offset 1,

and work offset 2 with the title of “Offsets”.

Offsets

- Home Position

- Park Position

-Work Offset 1

-Work Offset 2

The DrawParametersSubScreen command is chosen from the main sub-screen

menu list. Once chosen, it will give the user access to the machine parameters

screen, TCPIP configuration screen, and the com port screen.

Parameters

- Machine Parameters

- TCPIP Configuration

- Com Port


177

The DrawSoftLimitsSubScreen command can also be chosen from the main sub-

screen menu. This screen allows the user to choose between the upper of lower

soft limits with the title of “Soft Limits”.

Soft Limits

-Upper Limits

-Lower Limits

The DrawOffsetScreen command will draw one of four offset chosen by the

user. All screens have the same design except the title will change depending

upon which offset screen is chosen which could be home position, park

position, work offset 1, or work offset 2. The left side of the screen is titled by

the words “Set Position” which are the positions that the machine is currently

using for the offset which was chosen. Underneath the title, the four axes are

shown with the corresponding positions next to them. On the right side of the

screen, there is a title that says “Current Pos” which allows the user to change

the offset on the set position to the current position on which the machine has

just stopped on. Underneath the title, there is the variables that correspond to


178

each axes’ position on the machine. Below the left side axes, there is an accept

button to allow the user to switch the set to the current positions, and below

the right side axes, there is a cancel to stop the action just taken by the user.

TitleSet

PositionCurrent

Pos

X:

Y:

Z:

A:

Accept Cancel

The DrawMachineParameters command will draw the machine parameters

based upon the values the job allows the machine to work at. The screen will

carry the title “Parameter Screen 1”. Below the title, every machine

parameter will be displayed with its corresponding value next to it.


179

Machine Parameters

Max Speed:

Acceleration:

Rapid Max:

Rapid Min:

Deceleration:

Jog Speed:

Max Jog Speed:

Max Feed:

Min Feed:

Jog Increment:

The DrawSoftLimits command will draw either the upper or lower limits of the

machine’s current job depending upon which the user chooses. The screen’s

title will state which limits the user wants to use. On the left side of the screen,

the secondary title will be “Set Position”, and on the right side of the screen,

the secondary title will be “Current Pos”. Below the left title, there will be

labels for each axis’ dimension followed by its set value. Below the right title,

there will just be the values corresponding to the machine’s current position

on the table. Below the left values, there will be an accept button to change

the set position to the current position, and below the right values, there will

be a cancel button to stop the action just taken.


180

Upper Limits/Lower LimitsSet

PositionCurrent

Pos

X:

Y:

Z:

A:

Accept Cancel

The DrawTCPIPConfiguration command will draw and display the information

coming into the machine from the Ethernet connection when used. It will

display the title “TCP/IP Configuration”. It will have a labels under it stating the

title of the information being uploaded from the outside connection with each

label’s information below it displayed in the form xxx.xxx.xxx.xxx.


181

TCP/IP Configuration

Ip Address

xxx.xxx.xxx.xxx

Subnet Mask

xxx.xxx.xxx.xxx

Default Gateway

xxx.xxx.xxx.xxx

xxx.xxx.xxx.xxx

Primary DNS

Secondary DNS

xxx.xxx.xxx.xxx

The DrawComPort command will draw and display information incoming to

the machine from its serial ports. At the top, it will display the title “Com Port”

and underneath say “Communications”. Below the title will be the first label

for baud rate and its information right underneath the title. The next title will

be for the stop bits, and after the title, there will either be the words one stop

bit, one and a half stop bits, or two stop bits depending upon what information

the pendant receives. Below this title, there will be a title for the port’s flow

control followed by either the words none, hardware, or Xon/Xoff depending

upon what form of information flow the machine receives. The next title will

show parity within the incoming information. It can detect if the information

has no parity, odd parity, or even parity. The final two titles will be display

information if the flow control is using the Xon/Xoff format. The first title will

be for Xon character and the second title will be for the Xoff character.


182

Com Port

Communications

Baud Rate

Stop Bits:

Flow Control:

Xon Char:

Xoff Char:

Parity:

The DrawFileScreen command will display the file directories from the

uploaded jump drive. It will have the root title of the jump drive at the top of

the screen. Below the title, there will be the folder icon followed by its name.

Below this, there will be the file icon followed by a list of each file name

displayed after and continuing below. If the page isn’t big enough to fit all files,

the remaining files can be found below the file screen by using the up and

down buttons.


183

Root:

Folder Name

File Name

11.1.5 Support Source File:

This file is used to support the functions inside the CNC. These functions are

public to all source files.

IntToString()

The IntToString command will change a Integer to a String. This command is

being used to change the position for the X, Y, Z, and A into a string to be

printed on the LCD Screen. This command is what uses the Buffer[6] array

from the Screens.h. The function of this command takes each integer that is

given from the CNC and divides it first by 1000 until it can’t be divided

anymore and it is incremented into an integer character. It does this

process all the way down to 1. For example, if we had 21.02 as the number

it divides first by 1000. It can divide it 2 times so it increments the character

to 2 and places it in the first array block. It then divides it by 100 and the

number can be divided only once so it increments the 2nd array block to 1.

The third block becomes a “.” so it splits the numbers into its appropriate

value. The next number is 0 so the dividing by 10 is skipped so it places a 0

in the fourth array block. Finally the last number is 2 so it is divided by 1.


184

The character array block is incremented to 2 so the string then becomes

“21.02”.

2 1 . 0 2 2 1 . 0 2

Integer String

**Image taken from Windows XP Database

12. APPENDIX C

12.1.1 Test Data


12.1.1.1.1 Voltage Measurement

12.1.1.1.1.1 Input Voltage Measurement

Test Nominal (VDC) Actual (VDC) Tolerance (VDC)

24 Vdc Input 40 41.90 <50 +12 Vdc Input 20 19.96 <25 -12 Vdc Input -20 -22.00 >-25

12.1.1.1.1.2 Output Voltage Measurement

Test Nominal (VDC) Actual (VDC) Tolerance (VDC)

24 Vdc 24 24.00 5% (22.8 to 25.2) +12 Vdc 12 11.96 5% (11.4 to 12.6 -12 Vdc -12 -11.99 5% (-12.6 to -11.4) 5 Vdc 5 5.03 5% (4.75 to 5.25)

12.1.1.1.2 Voltage Ripple Measurement

12.1.1.1.2.1 Input Ripple Measurement

Test Nominal Actual (V pk-pk) Tolerance (V pk-pk)

24 Vdc Input - 2.5 <= 1


185

+12 Vdc Input - .75 <= 1 -12 Vdc Input - .80 <= 1

12.1.1.1.2.2 Output Ripple Measurement

Test Nominal Actual (mV pk-pk) Tolerance (mV pk-pk)

24 Vdc - 2V < 600 +12 Vdc - 150 < 300 -12 Vdc - 150 < 300 5 Vdc - 110 < 150

12.1.1.1.3 Slow Turn On

Test Nominal (Seconds) Actual (Seconds) Tolerance

+12Vdc 15 25 N/A -12Vdc 15 15 N/A 5Vdc 15 16 N/A

12.1.1.2 Optical Isolation Measurements

12.1.1.2.1 Response Time Measurements

12.1.1.2.1.1 Optical Isolator Response Time

Test Frequency(kHz) Rise Time Nominal

Fall Time Nominal

Actual(us) Rise | Fall

Tolerance (us)

ENABLE (J1-13) 1 - - 80|60 < 100 GND (J1-14) | < 100

| < 100


186

RESET (J1-15 ) 1 - - 80|60 < 100 GND (J1-16) | <100

| <100 MS1 (J1-17 ) 1 - - 80|60 < 100 GND (J1-18) | <100

| <100 MS2 (J1-19 ) 1 - - 80|60 < 100 GND (J1-20) | <100


187

12.1.1.2.1.2 Optical Couplers Response Time

Test Frequency(kHz) Rise Time (ns) Nominal

Fall Time (ns) Nominal

Actual (ns) Rise | Fall

Tolerance (ns)

X-DIR(J1-3 ) 1 - - 23|5 < 100 GND (J1-4) 10 - - 33|5 < 100

100 - - 28|10 < 100 1MHz - - 30|10 < 100 X-STEP (J1-1) 1 - - 23|5 <100

GND (J1-2) 10 - - 33|5 <100 100 - - 28|10 < 100

1MHz - - 30|10 <100 Y-DIR (J1-7 ) 1 - - 23|5 <100

GND (J1-8) 10 - - 33|5 < 100 100 - - 28|10 <100 1MHz - - 30|10 <100

Y-STEP(J1-5 ) 1 - - 23|5 < 100 GND (J1-6) 10 - - 33|5 < 100

100 - - 28|10 < 100 1MHz - - 30|10 < 100 Z-DIR (J1-11) 1 - - 23|5 <100 GND (J1-12) 10 - - 33|5 <100

100 - - 28|10 < 100 1MHz - - 30|10 <100

Z-STEP (J1-9 ) 1 - - 23|5 <100 GND (J1-10) 10 - - 33|5 < 100

100 - - 28|10 <100 1MHz - - 03|10 <100


188

12.1.1.2.2 Frequency Response Measurements

12.1.1.2.2.1 Optical Isolator Frequency Response

Test Pins

Frequency(kHz) High(VDC) Nominal

Low(VDC) Nominal

Actual(VDC) High | Low

Tolerance (VDC) High | Low

ENABLE (J1-13)

1 5 0 5|.010 >= 0.7 | <= 0.3

GND (J1-14) | >= 0.7 | <= 0.3 | >= 0.7 | <= 0.3

RESET (J1-15 ) 1 5 0 5|.010 >= 0.7 | <= 0.3 GND (J1-16) | >= 0.7 | <= 0.3

| >= 0.7 | <= 0.3 MS1 (J1-17 ) 1 5 0 5|.010 >= 0.7 | <= 0.3 GND (J1-18) | >= 0.7 | <= 0.3

| >= 0.7 | <= 0.3 MS2 (J1-19 ) 1 5 0 5|.010 >= 0.7 | <= 0.3 GND (J1-20) | >= 0.7 | <= 0.3

| >= 0.7 | <= 0.3


189

12.1.1.2.2.2 Optical Coupler Frequency Response

Test Pin Frequency(kHz) High(VDC) Nominal

Low(VDC) Nominal

Actual High | Low

Tolerance (VDC)

High | Low

X-DIR(J1-3 ) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3 GND (J1-4) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3

100 4 0 3.75|-.25 >= 0.7 | <= 0.3 1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3 X-STEP (J1-1) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3

GND (J1-2) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3 100 4 0 3.75|-.25 >= 0.7 | <= 0.3

1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3 Y-DIR (J1-7 ) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3

GND (J1-8) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3 100 4 0 3.75|-.25 >= 0.7 | <= 0.3 1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3

Y-STEP(J1-5 ) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3 GND (J1-6) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3

100 4 0 3.75|-.25 >= 0.7 | <= 0.3 1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3 Z-DIR (J1-11) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3 GND (J1-12) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3

100 4 0 3.75|-.25 >= 0.7 | <= 0.3 1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3

Z-STEP (J1-9 ) 1 4 0 3.80|-.30 >= 0.7 | <= 0.3 GND (J1-10) 10 4 0 3.80|-.30 >= 0.7 | <= 0.3

100 4 0 3.75|-.25 >= 0.7 | <= 0.3 1MHz 4 0 3.63|-.25 >= 0.7 | <= 0.3


190

12.1.1.3 Motor Power Supply


12.1.1.3.1.1 Output Voltage Measurement

Test Nominal (VDC)

Actual (VDC)

Tolerance (VDC)

Vm (No Load) 45 45.9 12 < Vbb < 48 Vm(Full Load) 40 40.0 12 < Vbb < 48

Vm (Transient Voltage Spikes) - 52 < 55

12.1.1.3.1.2 Voltage Ripple Measurement

Test Nominal Actual(V) Tolerance (V pk-pk)

Vm (No load) - .250 <= 1

12.1.1.4 Voltage Reference


Test Nominal (VDC) Adjustable

Actual (VDC)

Tolerance (VDC)

X-Vref .6880 to 1.6168 .6970 to 1.6210 .6192 to 1.7785 Y-Vref “ .6975 to 1.6180 “ Z-Vef “ .6960 to 1.6205 “


Test Nominal (IDC) Steady State

Actual (IDC) Steady State

Tolerance (IDC) Steady State

Driver Board Ready 533uA 540uA (525 to 652) uA Vbb Good Signal 533uA 552uA “

Fault Signal No Fault | Fault 2.2mA | 0

2.2mA/0 N/A

12.1.1.6 Fuse Blown Indicators

Test Fuse Blown Indicators

Nominal Actual

+12 Vdc PASS PASS -12Vdc PASS PASS 24Vdc PASS FAIL


191

12.1.2 Calculations Section

12.1.2.1 Voltage Regulator (5 Vdc supply)

Calculations and Graphs for determination of input supply using Matlab are shown below. The

determination of the VREG1 was determined by the supply requirements.

Supply Current Requirement of VREG1

1. Driver = 10mA*3 Chips

2. Opo-Coupler=5mA*6 Chips

3. Opo-Isolator=4mA

4. Vbb Protection=1mA

Total Current = 65mA

_________________________________________________________________________

% Volatage Regulator 5Vdc

% Determination of the the input supply to the 5Vdc Regulator

Rthja=100

Vp=6:1:22;

Vreg=5

Tamb=20;

Ireg=(150-Tamb)./(Rthja.*(Vp-Vreg));

figure(1)

plot(Vp,1000*Ireg)

title('Maximum Output Current at Different Input Voltages to VREG1');

xlabel('Input Voltage To VREG1 (V)');

ylabel('Ouput Current (mA)');


192

% Volatage Regulator 5Vdc

% Maximum output of Regulator

Rthja=100

Vp=12

Vreg=5

Tamb=0:1:175;

Ireg=(150-Tamb)./(Rthja*(Vp-Vreg));

figure(2)

plot(Tamb,1000*Ireg)

title('Maximum Output Current of VREG1 with Volatge Input set at 12V');

xlabel('Temperature (Celsius)');


193

ylabel('Ouput Current (mA)');

axis([0 175 0 250]);


194

12.1.2.2 Voltage Regulators (+-12, 24 Vdc Supplies)

4.32kR2 24VdcVout For



uA50I,V25.1V,240RLet

)3(

adjI

1R

refV

refV

outV

2R)2(

)2(2

R*adj

I

2R

1R

1ref

Vout

V

2R*

adjI

2R

1R

*ref

Vref

Vout

V

)1(2

R*)adj

Iref

I(1

Rref

Iout

V

adjref1


195

12.1.2.3 Voltage Reference Circuit

Calculates the value of and for a given , sense resistor ,

supply voltage and minimum voltage .

S(max)tripDMAXDD

CD

DM

MIIND

C

D

R8*IVVVR*I xWhere

)2(R1x

VRR

)1(

1x

VV

RR

Calculates the value of SETV when values of and are selected.


196

)5()Rc

X,0Rf

(XSET

V)Rc

X,1Rf

(XSET

VSET

ΔV

(4))m

RRc

X*Rc

)((ohm/turn

RfX*

Rf(ohm/turn)R

DV

SETV

RfX*

Rf(ohm/turn)R

DV

RfRR

DV

TR

DV

TIwhere

(3))m

RC

(RT

ISET

V

RcX*

Rc(ohm/turn)

CR

RfX*

Rf(ohm/turn)

RfR

RfRR

TR

CR

mR

DRRLet

*See Voltage Reference Circuit

12.1.2.3.1

Calculations for Voltage Reference Circuit for Rd and Rm using Matlab.

Vd=12; %supply voltage

Itmax=4.7; % Maximum Trip Current

Rs=.0430 ; % Sense Resistor plus trace resistance

Rc=2*10^3; % Coarse Adj resitsor

display(' When Vmin=.688')

Vmin=.688;

x=Vd-(Itmax.*(Rs*8));

Rd= Rc./(((Vd-Vmin)./x)-1)


197

Rm= (Rd.*(((Vd)./x)-1))-Rc

Itmin=Vmin./(Rs*8)

Vmax=Itmax.*(Rs*8)

Itmax=Vmax./(Rs*8)

When Vmin=.688

Rd = 2.2358e+004

Rm = 1.4815e+003

Itmin = 2

Vmax = 1.6168

Itmax = 4.7000

12.1.2.4 Optical Isolator

)2(

)1(

If

VfVinRd

Rc

VoutVccIc

kΩ.Rd

mAIfV,VfV,.VinLet

1501

2133

kRc

mAIcVVoutVVccLet

10

5.,0,5


198

12.1.2.5 Optical Coupler

)1(If

VfVinRd

kΩ1Rd

mA3.2IfV,1VfV,3.3VinLet

12.1.2.6 Vbb Protection Circuit

)1(

tripI

tripV

Rs

ΩRRs

mAImVV triptrip

180

65,65

12.1.2.7 Input Filter Capacitor

)1(**2

rippleVf

loadI

FC

12.1.2.7.1 Low Voltage Power Supply

uFF

C

Vripple

VHzfmAload

ILet

416

1,120,100


199

12.1.2.7.2 Motor Voltage Power Supply

mFF

C

Vripple

VHzfAload

ILet

35

1,120,4.8

12.1.2.8 Fuse Blown Indicator

)2(

)1(

2 RIP

I

VVR LEDUREG

12.1.2.8.1 +-12Vdc Fuse Indicator

resistorperWmWP

kΩRRR

mAIV,VV,VVLet LEDUREGMOSFETS

8/1100

0.46159

56.122,0

12.1.2.8.2 24Vdc Fuse Indicator

resistorperWmWP

kRRR

kR

mAIV,VV,VVLet LEDUREGMOSFETS

8/195

7.462602

40.9

5.46.144,0

12.1.2.9 Driver Outputs

Tests were conducted to determine a more accurate value of data required. The test setup is shown in

figure ___.


200

)2(If

VfVinRd

)1(Rc

VoutVccIc

Vin was adjusted until a value of approximately 1 Volt was seen on the output (Vout).

kRd

kRc

15.1

10

Data used to calculate the Driver Output signals: Board Ready Signal and Vbb Ready Signal.

652uA 533uA to are IFor limits Tolerance :Note

5.685kΩRc

3.3V is Board Controlleron isolators optical Supply toPower

394uA. providemust Isolator Opticalon Current Output :Note

uA394Ic

uA533IfI

V047.1VfV,060.1V,V66.1V

SET

SET

OUTIN

12.1.2.9.1 Driver Board Ready Signal

uA547I 20k set to wasR72

20.5kΩR72I

Vf12R72

SET

SET

12.1.2.10

12.1.2.11


201

12.1.2.12

12.1.2.12.1 Vbb Ready Signal

M15I

Vx70R

k178.26I

VfVx71R

k816.46I

VxVbb69R

)2(71R

Vf

71R

1

70R

1

69R

171R

Vf

69R

Vbb

R71

VfVxI

(1) 0R71

VfVx

R70

Vx

R69

VxVbb

uA1I 534uA,I 533uA,I 1.047V,Vf 40V,Vbb 15V,VxLet

70R

71R

69R

SET

R71R69SET


202

uA542IV0975.15Vx

70R

1

70R

1

69R

171R

Vf

69R

Vbb

Vx (1)

3.57MR70 26.1kΩ6R71 46.4k,R69

:conditonscircuit and valuesComponent Circuit Final

3.57MR70 :set Componets

M5714.370R

uA2.4I

uA8.538I

uA6.534I

26.1kΩR71 46.4k,R69 :set Componets

SET

70R

69R

SET

12.1.2.12.2 Fault Signal

k2k9765.1mA2

047.1581R)2(


203

12.1.3 List of Figures

12.1.3.1 Figure 34 Voltage Reference Simplified Circuit Diagram

Vd

Rd

Rf

Rc

Rm

Vset

Vref

Vref = Vset


204

12.1.3.2 Figure 35 Optical Isolator Circuit Diagram

Vin Vf

Vcc

RdRcIc

If Vout


205

12.1.3.3 Figure 36 Voltage Regulator Simplified Circuit Diagram

R1

R2

VoutVin

Vref

Iadj

Iref

LM317, LM377


206

12.1.4 Simulations

Figure 37 Motor Voltage Simulation


207

Figure 38 Simulation # 1: Motor Voltage Ripple at Normal Load (3.3 A)


208

Figure 39 Simulation # 2: Motor Voltage Ripple at Full Load (8 A)


209

Figure 40 Fuse Blown Test for 12Vdc and -12Vdc


210

Figure 41 Fuse Blown Test for 24Vdc


211

Figure 42 Low Voltage Power Supply Transient Analysis


212

Figure 43 Low Voltage Power Supply Input Filter Capacitors Voltage Ripple


213

Figure 44 Low Voltage Power Supply Ripple Rejection: +5Vdc (yellow), 12Vdc (green), -12Vdc (blue)


214

13. References

[1] dsPic30F3013 Data Sheet

http://ww1.microchip.com/downloads/en/DeviceDoc/70139C.pdf

[2] Goldelox-SGC Command Set: Software Interface Specification

http://www.4dsystems.com.au/downloads/Semiconductors/GOLDELOX-

SGC/Docs/GOLDELOX-SGC-COMMANDS-SIS-rev2.pdf

http://ww1.microchip.com/downloads/en/DeviceDoc/70139C.pdf

www.4dsystems.com.au/downloads/Semiconductors/GOLDELOX-SGC/Doc

www.4dsystems.com.au/downloads/Semiconductors/GOLDELOX-SGC/Doc

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