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Preliminary Design Report(Shake and Bake)

Andrew TownsendRyan JohnsonKara Tobey

Aldo CamposGrant Arthur

Shake and Bake: Preliminary Design Report October 12, 2011

Table of Contents

Background......................................................................................................................................3

Principles of Operation....................................................................................................................4

System Description and Block Diagrams........................................................................................5

Power Supply...........................................................................................................................7

User Interface...........................................................................................................................9

Control Unit............................................................................................................................12

Dispensing Unit......................................................................................................................15

System Analysis.............................................................................................................................17

Extrusion Screw and Housing Design....................................................................................18

Motors and Gearing................................................................................................................21

Program Design......................................................................................................................22

Project Plan....................................................................................................................................24

Organization and Management..............................................................................................25

Budget....................................................................................................................................26

Gantt Chart Fall 2011.............................................................................................................27

Gantt Chart Spring 2012.........................................................................................................28

Pert Chart Fall 2011...............................................................................................................29

Pert Chart Spring 2012...........................................................................................................30

Work Breakdown Structure Fall 2011....................................................................................31

Work Breakdown Structure Spring 2012...............................................................................33

Appendix A:...................................................................................................................................36

2


Background

Fresh-baked cookies, banana bread, and hot biscuits are integral to American culture.

Hundreds of such deserts, breads and pastries are made by household cooks every year, from

small children standing on chairs to the moms who help them stir to great-grandmothers who

have prepared such treats for several generations. Small-scale baking is a ubiquitous activity

which captures the attention of many. Every local coffee shop hides someone whipping up a

batch of blueberry scones in the back, and many small restaurants offer their own homemade

desserts.

The system of measuring out ingredients for such projects is a standard process that has

remained steadfast for generations. The process is simple, but time-consuming and messy.

Frequently, ingredients are spilled onto the countertop or floor during measuring. If a scoop

needs to be reused, it must be washed first in order to avoid contamination and all measuring

utensils must be washed again at the end of the process. This cleaning up is generally detested

by bakers, who would rather spend their time on other activities. Also, accuracy is sacrificed

when the baker is in a hurry and doesn’t have time for exact measurements.

A device capable of making accurate measurements without the need for cleanup would

make baking much more enjoyable for users. The Shake and Bake ingredient dispenser speeds

up and cleans up the baking process, allowing cooks to focus on other elements of their work,

rather than fussing with measurements. The machine’s functions greatly simplify the common

but inefficient process that includes opening containers, retrieving measuring utensils, measuring

out ingredients, cleaning up spills, closing containers, and washing utensils.

This device measures out dry ingredients common to baking in increments specified by

the user. In addition to delivering accurate quantities in a timely manner, it stores the ingredients

and keeps them fresh, dry and clean. It eliminates spills, the need to search for and wash

measuring cups and spoons, and the headache of maneuvering many different containers. Also,

the device can store previously used recipes and doesn’t forget how many cups it has measured

already, as cooks are notorious for doing. The ingredient dispenser generally creates a cleaner,

more efficient baking environment.

3


Principles of Operation

The ingredient dispenser will store six different ingredients (flour, white sugar, brown

sugar, salt, baking soda, and baking powder) in sealed containers made of FDA-approved

materials. It will take input from the user, allowing measurements to be specified in cups,

tablespoons, teaspoons, or grams. It will then dispense the ingredients in amounts accurate to

within 5% of the user input. It will store at least five recipes in memory, allowing the user to

recall them instead of manually entering commonly used recipes repeatedly. The machine will

communicate with the user visually via a LCD screen.

The device will perform more quickly than a human measuring by hand (including

retrieving, using, washing and putting away necessary instruments). It will dispense one cup of

flour, white sugar, or brown sugar in 75 s or less and one tablespoon of salt, baking soda or

baking powder in 75 s or less. The containers will be easily detachable, making them easy to

clean. The finished structure will be easy to move and store, weighing no more than 15 kg when

empty, and having dimensions no more than 0.5 m wide by 1.0 m long. It will be no noisier than

other kitchen appliances, producing less than 90 dB at a distance of 1 m.

4


System Description and Block Diagrams

5


The ingredient dispenser consists of four primary subsystems: the power supply, the user

interface, the control unit, and the dispensing unit. The relationships between these four

components are shown in Fig. 1. The power supply provides electrical power to the other three

units. The user interface communicates with the user, receiving commands and providing

information about the dispensing status. The control unit determines the ingredient and the

amount of that ingredient to be dispensed. The dispensing unit transfers the ingredients out of

the unit for use by the user.

Figure 1: Level 1 Functional Block Diagram for Device

These four units are further decomposed in level 2 block diagrams on the following

pages. For all diagrams, the inputs and outputs for each unit are indicated with arrows. Dotted

lines represent a signal, solid lines represent power, and bold lines represent materials.

6


Power Supply

The power supply converts a 120 V AC signal from a standard home wall socket into a

12 V DC signal. It then steps this voltage down to the amounts required by the various electrical

units used in the device. The power is supplied to the microprocessor, memory, keypad, scanner,

screen, sensors and motors. The power supply will be purchased or built to meet requirements.

The level 2 block diagram for the power supply is shown in Fig. 2. This diagram includes the

components that will be needed if the power supply is built.

Input 120 V AC from wall

Output 5 V DC, 45 mA to microprocessor

5 V DC, 3 mA to memory

5 V DC, 45 mA to keypad

5 V DC, 25-80 mA to scanner

3.3 V DC, 8.6 mA to LCD screen for logic

12 V DC, 20 mA to LCD screen for backlight

5 V DC, 2 mA to each sensor

12 V DC, 82 mA to each motor

7


Figure 2: Level 2 Functional Block Diagram for Power Supply

AC Voltage Step Down

This component drops the incoming 120 V AC to 20 V AC.

Rectification

Diodes are used to rectify the AC signal.

Filter to Remove Ripple

A filter is used to stabilize the signal, creating a steady output.

DC Step Down

Three DC step down components reduce the 20 V to the voltages required by the various

components that are powered by the power supply. The voltage is first stepped down to 12 V,

which is used to power the motors and the screen backlight. It is then stepped down to 5 V,

8


which is used to power the microprocessor, memory, sensors, keypad and scanner. Finally, the

voltage is stepped down to 3.3 V, which is used to power the screen logic.

User Interface

The user interface is the system through which the device communicates with the user,

prompting the user for input, receiving commands, and providing information about the

dispenser’s status. It consists of a keypad, barcode scanner, on/off switch, and LCD screen. The

level 2 block diagram for the user interface is show in Fig. 3.

Figure 3: Level 2 Functional Block Diagram for User Interface

9


KeypadThe keypad takes input from the user, who chooses the desired ingredient and

measurement combinations, which are then sent to the microprocessor.

Input Power 5 V DC, .5 mA

Mechanical signal from user pushing keypad buttons

Output Digital signal to microprocessor 0-5 V DC, 0.5 mA

ScannerThe scanner reads barcodes that contain recipes (combinations of ingredients and their

corresponding measurements) and sends this information to the microprocessor.

Input Power 5 V DC, 25-80 mA

Values encoded in barcode provided by user


SwitchA mechanically operated switch is the means by which the user tells the device to begin

dispensing. Each container has its own switch which, when engaged, connects the corresponding

motor to the power supply. If the microprocessor has sent a signal to the motor at this point,

engaging the switch will cause the motor to begin rotating.

Input Power 12 V, 82 mA

Mechanical manipulation by user

Output 12 V, 82 mA to motor (each)

10


LCD ScreenAn LCD screen outputs information from the microprocessor to the user. The screen is

used to interact with the user and provides information about which containers are currently

programmed, what measurements have been entered, and which recipes are stored.

Input Power 3.3 V, 8.6 mA

Power 3.3 V, 20 mA

Digital signal from microprocessor 0-5 V DC, 0.5 mA

Output Visual output to user

11


Control Unit

The control unit consists of the microprocessor, memory and sensors. The control unit

controls and monitors the dispensing process. It gathers information about the container weights

from the sensors, sends information to and retrieves information from the user interface, and

signals the motors to turn on or off. The level 2 block diagram for the control unit is shown in

Fig. 4.

Figure 4: Level 2 Functional Block Diagram for Control Unit

12


MicroprocessorThe microprocessor takes information from the user via the keypad and scanner. It

controls which containers dispense and how much ingredient they dispense based on user input.

The microprocessor controls dispensing by engaging and disengaging the motors. It gathers

information about the containers through the force sensors, monitoring the amount of ingredient

in a container throughout the dispensing process. The microprocessor communicates to the user

with a screen.

Input Power 5 V DC, 45 mA

Analog signals from sensors 0-2 V DC, 0.5 mA

Digital signal from keypad 0-5 V DC, 0.5 mA

Digital signal from scanner 0-5 V DC, 0.5 mA

Digital signal from memory 0-5 V DC, 3 mA

Output Digital signal to motor 0-5 V, 0.5 mA (each)

Digital signal to LCD screen 0-5 V, 0.5 mA

Digital signal to memory 0-5 V, 0.5 mA

MemoryMemory, which may be internal or external to the microprocessor, stores combinations of

ingredients as recipes. This allows the user to recall and use stored recipes.

Input Power 5 V DC, 3 mA

Digital signal from microprocessor 0-5 V DC, 0.5 mA

Output Digital signal to microprocessor 0-5 V DC, 3 mA

13


SensorsForce sensors measure the weight of each container and send this information to the

microprocessor, allowing the microprocessor to monitor the amounts of ingredients in each

container. During dispensing, the microprocessor uses the change in weight of a container to

determine how much of an ingredient has been dispensed.

Input Power 5 V DC, 2 mA (each)

0-35 N force from containers


14


Dispensing Unit

The dispensing unit consists of the ingredient containers, dispensing mechanisms and

motors. This system holds the ingredients and uses mechanical power to move the ingredients

out of the containers. The level 2 block diagram for this unit is shown in Fig. 5. Descriptions of

each component follow.

Figure 5: Level 2 Functional Block Diagram for Dispensing Unit

15


ContainersSix separate containers will be used to hold various ingredients. There are two different

container sizes. The three larger containers are designed to hold flour, white sugar, and brown

sugar. Three smaller containers hold salt, baking soda, and baking powder.

Input Ingredients, from user

Output Ingredients, to dispensing mechanism

0-35 N force, to sensors

Dispensing MechanismThe dispensing mechanism is a mechanical assembly used to move ingredients out of the

containers and into a receptacle provided by the user. The main component is a threaded screw

which pushes the ingredient as it rotates. This screw is turned by a geared motor.

Input Ingredients, from containers

Mechanical torque from motors

Output Ingredients, to user

MotorsThe motors mechanically power the dispensing mechanism. They are turned on and off

by the microprocessor when it receives instructions for a container. In addition, the motors will

take a signal from the user via the “dispense now” mechanism, engaging only when the user is

ready for dispensing.

Input Power 12 V, 82 mA each (from switch)

Digital signal from microprocessor 0-5 V, 0.5 mA (each)

Output Mechanical torque applied to dispensing mechanism

16


System Analysis

17


Extrusion Screw and Housing Design

Table 1 displays the material densities gathered from a chart published on simetric.co.uk.

Using these densities, a rudimentary screw and screw housing design have been started.

Table 1: Ingredient Densities

Ingredient Density (Kg/m^3) Density (Lb/in^3)flour 593.00 0.0214sugar 849.00 0.0307brown sugar 721.00 0.0260salt 1200.00 0.0434baking powder 721.00 0.0260baking soda 689.00 0.0249

As seen in Table 1, the salt has the highest density; therefore one would surmise that the

dispensing design will be critical on the salt properties because of the higher amount of mass in

the system when salt is used. However, the information that is actually critical in this regard is

the viscosity, not the density. This can be assumed because the amount of mass in this system is

so miniscule that the inertial forces involved to move the mass can be disregarded. This

assumption was affirmed by discussing the design with engineers working with the Molon

Motors Company. Based on this information, it can be assumed that the brown sugar will be the

most critical part of the dispensing design. This assumption has been made based on the fact that

all of the ingredients are dry and powder like with the exception of brown sugar which usually

has molasses or some other type of viscous syrup. This assumption was affirmed by talking with

a technical sales person with the Augers Unlimited Company.

Based on the information gathered by talking to representatives from Augers Unlimited

and Molon Motors, two screw designs could be implemented. This information is shown in

Table 2. These designs represent a rough range for the auger screw. Screw Design 1 being the

smallest and Screw Design 2 being the largest. Therefore, there is an expected volume range of

0.3 in3 to 14.5 in3 of material being pushed out by the screw at any given time.

18


Table 2: Table for Imputing Possible Auger Screw Designs

Screw Design

:

Outer Dia. (In.)

Root Dia. (In.)

Thread width (In.)

Threads/In.

Exposure Length

(In.)

Barrel Length

(In.)

Material in Exposure

Region (In.^3)

Material in Barrel (In.^3)

Total Materal In Screw (In.^3)

1 1.00 0.50 0.18 3.00 3.00 3 0.1471 0.1471 0.29432 2.00 0.50 0.18 3.00 3.00 3 7.2157 7.2157 14.4315

Table 3 and Table 4 show the mass calculations for each ingredient. This table was

formulated using each ingredient density value from Table 1 along with the total mass in the

system calculated for Screw Design 1 and Screw Design from Table 2. Doing this for the two

assumed screw size ranges can give estimated value for the maximum mass that will be pushed

through the auger screw at any given time. The maximum mass found based on the rudimentary

designs is .6256 pounds for our critical ingredient, brown sugar. This is the load the screw will

have to constantly push at varied rates to output the critical ingredient. This information will help

determine a torque requirement for the motors.

Table 3: Mass Calculations for Screw Design 1:

Screw Design 1:

Mass in Exposure Region

(Lbs)

Mass in Barrel (Lbs)

Total Mass in Screw (Lbs)

flour 0.0032 0.0032 0.0063sugar 0.0045 0.0045 0.0090brown sugar 0.0038 0.0038 0.0077salt 0.0064 0.0064 0.0128baking powder 0.0038 0.0038 0.0077baking soda 0.0037 0.0037 0.0073

19


Table 4: Mass Calculations for Screw Design 2:

Screw Design 2:

Mass in Exposure Region

(Lbs)

Mass in Barrel (Lbs)

Total Mass in Screw (Lbs)

flour 0.1546 0.1546 0.3092sugar 0.2213 0.2213 0.4426brown sugar 0.1880 0.1880 0.3759salt 0.3128 0.3128 0.6256baking powder 0.1880 0.1880 0.3759baking soda 0.1796 0.1796 0.3592

20


Motors and Gearing

Because significant friction occurs between the screw and material, the screw and

housing, and the material itself, an exact value for the torque required from the motor is difficult

to calculate. A model needs to be constructed and tested to incorporate friction values into

torque requirements. To acquire the torque requirement for the motors, various auger companies

and motor companies were consulted based on the project scope. These companies concluded

that several motors are capable of driving this dispensing system. They also concluded that there

are several motors that meet the specifications and fit the budget. One engineer from Molon that

was consulted estimated that the necessary torque would be between 2 and 5 inch pounds of

torques. From a table found on the internet, 557.6 in*lbs of torque is roughly one N*m.

Therefore, the metric torque requirement should not exceed 0.009 N*m of motor torque. The

current dispensing motors selected provide .3 N*m at 60 rpm. Because the torque supplied by

the motors is significantly higher than the torque requirements, the motor may be geared to

decrease torque and increase rpm to ensure that one cup of ingredient is dispensed in 75 seconds.

The flow rate required to achieve this dispensing time is 3.15 cm3/second. Using Screw Design

1, which outputs 8.576 cm3/rev, the minimum required rotational speed is 22.0 rpm for 75

seconds.

21


Program Design

In Figure 6, shown on the following page, the preliminary program is outlined with a

flow chart. This flow chart is a basic representation of how the device will operate. The program

will take multiple complex algorithms working together in order to produce the desired final

operation of the device. The basic functions within our flow chart incorporate:

The input of the user from the home screen

Checking to see if the contents of the containers have enough ingredients to dispense

the recipe entered

Give the user an option to save the recipe entered

Prompt the user to dispense when ready

22


Figure 6: Basic Overall Flow Chart Design for Program

23


Project Plan

24


Organization and Management

Team Shake and Bake consists of three mechanical engineering students, one electrical

engineering student, and one computer engineering student. The tasks will be assigned to project

members as follows:

Andrew Townsend - mechanical engineer

Andrew is the team leader, responsible for coordinating group meetings and

consolidating written reports. He is the primary engineer designing the dispensing mechanism

and choosing the motors and gearing that will be used to power this mechanism.

Ryan Johnson - mechanical engineer

Ryan is responsible for implementing the scales into the dispenser design. It is his job to

choose which sensors to use, where they will be placed, and how they will be configured. He is

also overseeing the structural design of the control unit, which will house many of the electrical

components, including the user interface and microprocessor.

Kara Tobey - mechanical engineer

Kara is the engineer designing the six bases and containers. She will address issue

regarding materials, configuration, connections between bases and containers, connections

between the different bases, and interfacing with the dispensing unit and sensors.

Aldo Campos - computer engineer

Aldo is in charge of selecting the microprocessor for the project and any additional

memory that is needed. He will be the primary engineer responsible for programming the

microprocessor to perform its various functions.

Grant Arthur - electrical engineer

25


Grant is designing and implementing the electrical components for this project. It is his

job to select the power supply, keypad, scanner, and LCD screen that will be used and to design

the circuit board. Grant is also in charge of keeping track of the budget and expenses.

Budget

Part Description Quantity Price

per

Unit

Tax and

shipping

Price

Total

Vendor

DC Motors Jammeco 38GM-253500 6 $15.95 $7.00 $102.70 jameco.com

Force Sensors Interlink Electronics

Standard 402 FSR

32 $6.44 $2.56 $208.64 DigiKey.com

Microprocessor DSPIC30F6015 2 $9.94 $0.00 $19.88 Newark.com

Barcode

Scanner

Adesso NuScan 3200

Optical Laser USB

Barcode Scanner

1 $111.95 $9.90 $121.85 bhphotovideo.com

Extrusion

Screw

6 $0.00 $0.00 3-D Printer

LCD Screen LCD DISP TFT 3.5"

320X240 B/L

1 $28.50 $6.24 $34.74 DigiKey.com

Power Supply Power One BLP55-3300 1 $44.51 $7.00 $51.51 Onlinecomponents.com

Gears $0.00 3-D Printer

PCB Board Professional Circuit Board 1 $51.00 $0.00 $51.00 expresspcb.com

Miscellaneous

Electronics

1 $50.00 $50.00

Keypad KEYPAD 12 KEY

FRONT PANEL MNT

1 $13.52 $2.56 $16.08 DigiKey.com

Material 1 $100.00 $100.00

Container

Material

DURAPLEX 2' x 4' Clear

Acrylic Sheet

1 $26.98 $1.89 $28.87 Lowe's

26


Miscellaneous

Shipping

$20.00 $20.00

Total $57.15 $805.27

27


28


Gantt Chart Fall 2011

29


30


Gantt Chart Spring 2012

Pert Chart Fall 2011

Pert Chart Spring 2012

Work Breakdown Structure Fall 2011

ID Task Description Deliverables Duration (Days)

People* Resources

O1.0 Project Management

Ensure that the project is on schedule and on budget

Specifications met in a timely manner

80 Andrew PC

O2.0 Documentation Keep records of design decisions, research, and tests

Engineering notebooks and A-3 reports

80 A, Al, G, K, R PC, Notebooks

F1.0 Project Selection Select a project A verbal decision 12 A, Al, G, K, R NotebooksF2.0 Requirement

SpecificationsTechnical Description of project goals

Document 16 A, Al, G, K, R PC

F3.0 System Design and Project Plan

Description of systems operation, project plan, and budget

Document 9 A, Al, G, K, R PC

F4.0 System Layout Develop a plan for device operation and functionality

Notebook documentation

11 A,Al, G, K, R Notebooks

F5.0 Device Design Design the device Detailed design of all components

47 A, Al, G, K, R PC

F6.0 Sensor Placement Select appropriate force sensors. Design appropriate electrical interface and placement

Detailed design, Schematics

7 Ryan PC

F7.0 Dispensing Mechanism Design

Design the extrusion method and motor system

Detailed design, Solidworks drawing

14 Andrew PC

31


F8.0 User Interface Select the appropriate LCD and bar code scanner. Design appropriate electrical interface

Detailed design, Schematics

20 Grant PC

F9.0 Microprocessor Interface

Microprocessor to operate all components

Detailed design 20 Aldo PC

F10.0

Container Housing Design

Design a housing for the motors and scales. Also holds the containers


14 Kara PC

F11.0

Power Supply Selection

Select a suitable power supply

Specifications 3 Grant PC

F12.0

Container Design Design a sealable container that can house the dispensing mechanism


18 Kara PC

F13.0

Electronic Housing Design

Design a housing for the microprocessor and electronics


13 Ryan PC

F14.0

Interim Design Interim system and subsystem design

Document, Presentation

23 A, Al, G, K, R PC

*A = Andrew, Al = Aldo, G = Grant, K = Kara, R = Ryan

32


Work Breakdown Structure Spring 2012

ID Task Description Deliverables Duration (days)

People* Resources

O1.0 Project Management

Ensure that the project is on schedule and on budget

Specifications met in a timely manner

79 Andrew PC

O2.0 Project Documentation

Keep records of design decisions, research, and tests

Engineering notebooks and A-3 reports

79 A, Al, G, K, R

PC, Notebooks

S1.0 Device Build Assemble of all the device components

Assembled components

38 A, Al, G, K, R

Workshop, PC

S2.0 Dispensing Mechanism Build

Build the dispensing mechanism used in our device


23 Andrew Work Shop

S3.0 Microprocessor Programming

Write the code for the microprocessor and download to device

A programmed and functional microprocessor

23 Aldo PC, Evaluation

board, Oscilloscope

S4.0 Sensor Build Build the platform on which the sensors rest and install sensors


23 Ryan Workshop

S5.0 User Interface Build

Build the components that will communicate with the user


23 Grant PC, Evaluation

board, Oscilloscope

S6.0 Container Build Build the containers, which will hold the ingredients


11 Kara Work Shop

S7.0 Container Housing Build

Build the housing for the containers


13 Kara Work Shop

S8.0 Container Testing

Perform a test on the containers to make sure it can hold a standardized bag, and also keep the ingredients fresh

Working components, that meet the specifications documented

14 Kara Workshop

33


S9.0 Container Housing Testing

Make sure the container attaches to it, and it can also hold the containers full of each ingredient


14 Kara Workshop

S10.0 Electronic Housing Build

Assemble all the electric components


11 Ryan Workshop

S11.0 Sensor Testing Test the sensors to ensure that they are registering the correct force and communicating to the microprocessor


11 Ryan Workshop

S12.0 Power Supply Testing

Test with different loads, the ripple, 30 Ω resistor, and with a oscilloscope to test the ripple


6 Grant Workshop

S13.0 Dispensing Mechanism Testing

Perform a test on the dispensing mechanism to ensure that it dispenses within the documented error


13 Andrew Workshop

S14.0 User Interface Testing

Perform a test within the components communicating with the user to make sure it is outputting the right things, and also receiving the right input


11 Grant PC, Evaluation

board, Oscilloscope

S15.0 Microprocessor Testing

Verify that the microprocessor is operating as desired

Functional microprocessor operating as desired

11 Aldo PC, Evaluation

board, Oscilloscope

S16.0 Electronic Housing Testing

Test all the output and input of the electric components


6 Ryan Workshop

34


S17.0 System Integration

Combine all the components

Complete System

19 A, Al, G, K, R

Workshop

S18.0 System Testing Test system for technical specifications; modify what is needed

Fully functioning prototype

18 A, Al, G, K, R

PC, Evaluation

board, Oscilloscope

S19.0 User’s Manual Describes how to use the device along with any special considerations

Document 11 A, Al, G, K, R

PC

S20.0 Final Report Final report about the prototype

Document 13 A, Al, G, K, R

PC

*A = Andrew, Al = Aldo, G = Grant, K = Kara, R = Ryan

35


Appendix A:

Technical Requirement Specifications

Overview: 36


Fresh-baked cookies, banana bread, and hot biscuits are integral to American culture. Hundreds of such deserts, breads and pastries are made by household cooks every year, from small children standing on chairs to the moms who help them stir to great-grandmothers who have prepared such treats for several generations. Small-scale baking is a ubiquitous activity which captures the attention of many. Every local coffee shop hides someone whipping up a batch of blueberry scones in the back, and many small restaurants offer their own homemade desserts.

The system of measuring out ingredients for such projects is a standard process that has remained steadfast for generations. The process is simple, but time-consuming and messy. Frequently, ingredients are spilled onto the countertop or floor during measuring. If a scoop needs to be reused, it must be washed first in order to avoid contamination and all measuring utensils must be washed again at the end of the process. The cleaning up that is necessary due to these factors is generally detested by bakers, who would rather spend their time on other activities. Also, accuracy is sacrificed when the baker is in a hurry and doesn’t have time for exact measurements; time is sacrificed when the baker slows down to focus on accuracy.

We believe that baking can be simplified with new technology, as so many other areas of life have been. There’s no need to keep using the same old process when the cookies can taste just as good and take less time!

Our ingredient dispenser measures out dry ingredients common to baking in increments specified by the user. The machine’s functions greatly simplify the common but inefficient process that includes opening containers, retrieving measuring utensils, measuring out ingredients, cleaning up spills, closing containers, and washing utensils.

Benefits of this product are numerous. In addition to dispensing accurate quantities in a timely manner, it stores the ingredients and keeps them fresh, dry and clean. It eliminates spills, the need to search for and wash measuring cups and spoons, and the headache of maneuvering many different containers. Also, the device can store previously used recipes and doesn’t forget how many cups it has measured already, as cooks are notorious for doing. The ingredient dispenser generally creates a cleaner, more efficient baking environment.

Problem Statement:

37


The majority of household cooks and small-scale bakers spend hours meticulously measuring out ingredients by hand, using an assortment of cups, spoons, and scoops. This method is time-consuming, requires repeatedly washing measuring utensils, and is often inaccurate when performed by rushed or easily distracted cooks. This device can speed up and clean up the baking process in homes and small restaurants, allowing cooks to focus on other elements of their work, rather than fussing with measurements.

Customer Needs: Dispenses "quickly" Reasonable size/weight in order to be easily handled Digitally stores combinations of ingredient measurements for repeated use Measures and dispenses multiple baking ingredients Device separates different ingredients Containers hold entirety of a standard-sized package of ingredients Keeps ingredients dry and clean Containers can be easily refilled when empty Containers are easily cleaned Not too "noisy" Notified when ingredient containers need to be refilled Measures contents in various units commonly used in baking Can customize recipes for various batch sizes Measures the amount of an ingredient(s) in response to user input Measures ingredients accurately

User Manual Rough Draft:

38


The ingredient dispenser is simple to setup and operate. The user needs only to fill the containers with the appropriate ingredients, and then enter the desired amounts of ingredients or a recipe code via the user interface. Finally, insert a bowl and manually activate the dispensing mechanism, and the process is complete!

1. Remove the device from storage.

2. Connect to the desired power source.

3. Power on the device.

4. Fill empty containers.

5. Allow machine to calibrate.

6. Input the recipe or ingredients to be used and the desired amounts.

7. Place bowl underneath dispenser.

8. Activate dispensing mechanism.

9. Repeat steps 7-8 until all desired ingredients have been dispensed.

10. Power off the device.

11. Store the device in desired location.

Technical Requirements Specification:

39


1. The time required to dispense one cup of ingredient should not exceed 75 seconds. (This is the approximate time a user needs to retrieve a measuring device and ingredient, use measuring device, wash measuring device, and put away measuring device and ingredient.)

2. The mass of the empty device should not exceed 15 kg. (This is the weight of an average countertop microwave.)

3. The device dimensions should be no greater than 0.5 m wide by 1.0 m long.

4. The device should have the capability to store at least five recipes in memory.

5. The device should have the capacity to contain no less than six separate ingredients. (This accounts for the most common baking ingredients: flour, white sugar, brown sugar, salt, baking powder, baking soda.)

6. The device should have containers with volumes no less than 0.4 L and no greater than 4.1 L. (This is based on standard ingredient package sizes, plus 20% extra volume)

7. The containers should be sealable.

8. The containers should detach from the main device in under ten seconds by a user familiar with the user manual.

9. The containers should be made out of an FDA-approved material.

10. The device should not produce a noise exceeding 90 dB within 1 m of the device. (This is the volume level of a standard household blender.)

11. The device should communicate with the user with visual output.

12. The device should perform according to user input.

13. The device should dispense correct ingredients within ±5% of the user input.

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NeedDispenses "quickly" *Reasonable size/weight in order to be easily handled * *Digitally stores combinations of ingredient measurements for repeated use *Measures and dispenses multiple baking ingredients *Device separates different ingredients *Containers hold entirety of a standard-sized package of ingredients *Keeps ingredients dry and clean *Containers can be easily refilled when empty * *Containers are easily cleaned * *Not too "noisy" *Notified when ingredient containers need to be refilled *Measures contents in various units commonly used in baking *Can customize recipes for various batch sizes *Measures the amount of an ingredient(s) in response to user input *Measures ingredients accurately *

Table 1: Matrix containing our customer needs and resulting metrics

Design Deliverables:1. A working automated ingredient dispenser.

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2. Comes with ingredient containers. Replacement containers can be purchased.

3. Baking ingredients will be supplied for testing purposes, but customers will be responsible for purchasing their own ingredients for home use of the device

a) System specifications

b) Budget

c) User manual

d) Final report, including detailed drawings, schematics, flow charts, code, and test results

Preliminary Test Plans:1. Dispensing Time

a. For flour, white sugar, brown sugar – User inputs 1 c of ingredient into device. Device is timed with a stopwatch from activation to completion of dispensing. Pass if this time is under 75 s for each ingredient.

b. For salt, baking soda, baking powder – User inputs 1 T of ingredient into device. Device is timed with a stopwatch from activation to completion of dispensing. Pass if this time is under 75 s for each ingredient.

2. Weight of device – Weigh empty device with a scale that is accurate to 0.5 kg. Pass if weight is less than 15 kg.

3. Device Dimensions – Measure length and width of device with a tape measure. Pass if length is 1.0 m or less and width is 0.5 m or less

4. Memory Capability – Use memory function to recall a recipe, then dispense each ingredient from the recipe into separate containers. Measure the amounts with standard measuring cups or spoons. Repeat test with four additional recipes. Pass if device completes task and ingredient amounts are accurate.

5. Number of Ingredient Containers – Pass if device contains six different containers for holding ingredients.

6. Size of Ingredient Containers – One container of each size is filled with water. Water is weighed with a digital scale. Pass if weight of water is between 0.4 and 4.1 kg. (Corresponds to 0.4 and 4.1 L of water)

7. Means of Keeping Ingredients Airtight – Submerge each sealed container in water for 10 s. Pass if all containers are able to keep out water.

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8. Time to Detach Containers – Three people who have read the user manual (not members of the Shake and Bake team) will detach all six containers from the device while being timed with a stopwatch. Users will then complete a survey about the understandability of the user manual and ease of use of the device. Pass if all three users complete the task in 60 seconds or less and select “agree” or “strongly agree” on the survey.

9. Composition of Containers – Pass if material used in containers is on FDA list of approved materials. If material from 3D printer is used in prototype, state in documentation that production units will be made of an FDA-approved material.

10. Noise Level – Measure the noise level (in dB) at a distance of 1 m from the device with a noise level meter. Pass if level is ≤ 90 dB.

11. Program Output – Pass if the device contains a component with visual output.

12. User Input and Measurement Accuracy – Input a measurement of 10 g of flour.

a. For flour, white sugar, brown sugar – Input a measurement of 10 g of flour. Dispense flour and weigh with a scale capable of measuring to the 0.5 g. Repeat experiment with measurements of 10 g, 50 g, 100g, and 150 g for each ingredient. Pass if all amounts are within 5% of the inputted amounts.

b. For salt, baking soda, baking powder – Input a measurement of 5 g of salt. Dispense flour and weigh with a digital scale capable of measuring to the 0.5 g. Repeat experiment with measurements of 5 g, 10 g, 25g, and 50 g for each ingredient. Pass if all amounts are within 5% of the inputted amounts.

Implementation Considerations:

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1. Ingredients must be restocked after repeated use. Device will notify user if there are not sufficient quantities to complete a function.

2. Containers designed to be periodically removed and cleaned manually.

3. Device designed to be self-calibrating.

4. Device to notify user if the proper ingredients are not in place.

Attachments:1. Patent Search: #5460209 – Applied in 1993 (See Appendix A)

Relevant Codes and Standards:

1. Sanitary Design and Construction of Food Equipment – University of Florida IFAS Extension (See Appendix B)

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