The Chur-RobotTeam Churro: Sharon Grimshaw, Maggie

Su, Louis Yi, and Morgan Zheng

Project GoalsSafe

Heat: no burnsMoving components: no pinching

EasyLoading: one container, easily removed, to fillCooking: machine removes when done

User choiceLength or number of churrosShape of churro

The Website

Initial Idea

Mechanical SubsystemExtruderCutter/ShaperStirrerLifterShaker

Mechanical Subsystem – Lifter

Pulley System Rack and PinionVertical liftingCan lift more weightCan still use 1 motor to

control movements of 2 sets of pulleys

Vertical liftingToo much load on gear/motor,

assuming initial idea of lifting stirrer and mesh grid assembly.

Use 1 motor to lift allGear & racks may be expensive

Initial Idea:Need to lift an assembly consisting of a stirring mechanism with a platform and a mesh grid.

Revised Idea:Only lifting mesh grid, but need to constrain vertical motion

Mechanical Subsystem - ExtruderHow to keep the threaded rod vertical?

Guide holeFixed to the motor

Will we have enough torque?Stepper motor instead of servoGears

Mechanical Subsystem - StructureStability through weight

Stability through attachment

Make supports heavier so that pieces don’t move

Overall smaller systemDifficult to move around

(multiple heavy pieces)

Attach supports (L brackets) to base and frames so they do not move

Easier to transport because only one piece

Easier to set up because distance between pieces is predefined

Large, bulky system

Electrical Subsystem - OverviewTo be powered on 12 volts

2 stepper motors3 servo

Temperature gaugeThermocoupleInstrumentation amplifierCharacter LCD display

Electrical Subsystem – Stepper Control

Basic H-bridge driver:Requires four input pins to control each motorRevised two-pin control:Uses transistors to set polarity across coils – two input pins per stepper

Software ComponentMotor control – Arduino Stepper/Servo Libraries

Stirrer/Shaker can run on a loopExtruder, cutter, and lifter relies on user input

GUIPython

Serial communication is relatively easy to deal with Lots of GUI libraries to choose from – some of which are

painful to deal withProcessing

Theoretically very good for Arduino GUIs Requires generic firmware that communicates with a

Processing Library – may interfere with the use of other Arduino libraries.

Where we’re going…

Questions? Comments? Concerns?