Guitar Neck Duplicator

By Eric Hall

Background

Difficult to Replicate Time Consuming Generally done by hand

What’s Available

• Expensive ($2,000 – $4,000)• Manually Operated

ProblemThe customer wants a more time efficient way to duplicate guitar necks.

Requirements

The process must perform high enough quality work so that only sanding is required to finish the product.

It must be able to duplicate a variety of different length necks (about 10"- 18" long).

Wear items must be easy to replace. It must be autonomous.

Solution

The device is based on the key maker concept. (The cutting tool follows a path that is dictated by a previously fabricated pattern part.)

The key maker is explicitly two dimensional, while the Guitar Neck Duplicator will be three axis (The third being rotational).

System Overview

PLC

Mechanical Concept

Traverse Motor Force Calculation

F

T

D

Torque = .2 x Diameter(Thread) x Force(axial)

45 LB*Inches = .2(.25 inches) x F

F = (45 LB*Inches) / (.2 x .25 inches)

F = 900 LB

Electrical Concept Overview

ProgrammableLogic

Controller

TraverseMotor

RotationMotor

Router

FrontLimit

Switch

RearLimit

Switch

InductiveCurrentSensor

Electrical Failsafe Concept Overview

TraverseMotor

FrontSafety Limit

Switch

RearSafety Limit

Switch

ProgrammableLogic

Controller

Software Concept Overview

TurnedOn

0 0 0

Setting

0 2 0

Set

0 0 0

Ready

0 0 0

Start

0 0 1

TraverseDirection 1

X 1 1

StopDirection 2

+1 0 1

TraverseDirection 2

X 0 1

StopDirection 1

+1 0 1

Stop

100 0 0

Button == Pressed Switch 1 == Pressed Button == Released Button == Pressed

Wait == 2 Seconds

Button == Pressed

Switch 2 == Pressed

State

0 0 0

Wait == 1 Sec

Switch 1 == Pressed

Wait == 1 Sec

Stepper == 100%

Stepper == 100%

Stepper (0 – 100%)Traverse Motor (0,1,2; stop,fwd,rev)Router (0,1; off,on)

Budget

DC Gearhead Motor $30.00

Stepper Motor $80.00

Aluminum $50.00

Spring $3.00

Limit Switches (4) Donated from ELT Dept.

Programmable Logic Controller $130.00

Relay Module (2) $88.00

Microcontroller $2.00

Router Supplied by Customer

Router Bit $25.00

Misc. Hardware $40.00

Total Cost $423.00

Work Breakdown

Timeline

Resource Management

Have a working agreement with another group

I am gaining machining assistance in return for software and electrical help.

Questions