Engineering H193 - Team Project

Tips for Motors & Handy Board Care Week 3 Day 2

Spring Quarter Gateway Engineering Education Coalition P. 1

Motor Cost Engineering H193 - Team Project

Motors Information

Shaft adapt?

Noise Suppr.

Volt. Adapt?

Other Total Tamiya Twin Motor Gearbox Acro name $9.50

2 @ $9.50

2 at $1.00

2 at $1.00

Yes $0.20

Hacked Servo 2 @ $9.00 / $9.50

Depends – maybe 2 bush wheels No 2 at $3.25

Yes $0.20

No 2 at $3.25

2 – 12 v Mabu chi at $3.00

$24.20

No $21.20

No $27.00

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Engineering H193 - Team Project

Motors Information

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Voltage Adaptors are required when the motor rated voltage is lower than the source voltage. The Acroname is OK. Hacked Servos run at 5 V. Tamiya motors run at 2.5 (recommended) or 3.3 volts. The Handy Board runs at ~9-10 volts.

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The carbon brushes from the Mabuchi 12 volt motors can replace the metal leaf brushes in the lower voltage motors and make them more reliable. This is STRONGLY RECOMMENDED if running at 3.3 volts. It may be needed when running at 2.5 volts.

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Engineering H193 - Team Project

Motors Information

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Noise – This means that the motors have enough electronic/electrical noise to alter data input from sensors or, more importantly, cause the Handy Board to reset. A capacitor provides the protection so that this does not happen.

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There is heavier gage 2-conductor wire for motors rather than thinner gage ribbon cable.

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Engineering H193 - Team Project

Tips for a More Enjoyable Robotics Experience

1. Handle the robot with some care. (Your wiring is fragile -- be careful. Reinforce joints with shrink tubing and/or hot glue. Design wiring so that the wire takes the strain and not the joint.) 2. Prevent short circuits. (The edge of circuit board of the Handy Board has battery voltage and 5 volts present. Protect it with electrical tape.) 3. Don't wedge your processor. (Don't use a printf in tight program loops. Among other problems, you could lose encoder counts.) Spring Quarter Gateway Engineering Education Coalition P. 5

Engineering H193 - Team Project

Tips for a More Enjoyable Robotics Experience

4. Reduce friction, keep things aligned. (It will actually improve battery life.) 5. Don’t zap charge for more than 20 minutes at a time (or less if battery begins to get warm).

6. Don't change or edit any files in the IC "libs" directory. (It only causes problems for the next team to use the computer.) 7. Clean up the work area before you leave. 8. Share the resources so they don't have to be placed on limited access.

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Engineering H193 - Team Project

Tips for a More Enjoyable Robotics Experience

9. Write code that allows your team to test a section of the course rather than the whole course.

10. Write code that allows your robot to continue to perform even if a sequential step is missed.

11. After turning HB off, wait a moment before turning it back on again. And only turn on HB with robot held up in the air.

12. Be prepared to run on either course and any of the four starting points. You will not have a choice in the final competition.

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Engineering H193 - Team Project

Tips for a More Enjoyable Robotics Experience

13.

Attach your sensors, particularly the ‘bump’ sensors (micro switches), so that they can be removed and replaced easily.

14. Make up a spare for critical sensors.

15. Use the same color wire(s) for the same types of devices. Avoid the "spaghetti" approach to wiring of the robot.

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Engineering H193 - Team Project

Tips for a More Enjoyable Robotics Experience

16. If a wheel is fastened to a shaft with set screws, you might want to file a flat spot on the shaft for each screw.

17. If you are using nuts and bolts, you may want to buy some cheap, bright colored nail polish to use as ‘Locktite’ to prevent your robot from coming apart.

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Engineering H193 - Team Project

Head to Head Competition Requirement

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Robots need to have a flag or plaque of their team’s letter and number – e.g., A1 – mounted on the robot and readable from both sides for judges.

It must be high contrast – black on white, white on dark blue, etc. and 1.5” high (e.g., Arial 140).

No fancy fonts!!!

Sample: A1 Spring Quarter Gateway Engineering Education Coalition P. 10

Engineering H193 - Team Project

Assignment Notes

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Due Friday: Sketches of chassis, chassis requirements, either good mockup or chassis with wheels

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Sketches must be three views in correct projection with scale and annotations

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A pictorial sketch to supplement above 3-view drawing will be looked upon favorably

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Requirements include estimated weight, identification of critical members Spring Quarter Gateway Engineering Education Coalition P. 11

Engineering H193 - Team Project

Lab Safety

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No open-toe shoes in lab Must have a TA “buddy” with you in the shop The shop will be open from 8:30 am – 4:30 pm on MW, 10:30 am to 4:30 pm on TR, and 8:30-1:30 on Friday.

This is the ME student shop and we are sharing it.

Keith is responsible for the shop, we will follow all safety rules in his shop ! Remember your safety glasses.

Only two people per team in the shop at a time Spring Quarter Gateway Engineering Education Coalition P. 12