2. Purpose of this Presentation Drivetrain Selection o Types of drivetrains o Types of wheels o Drivetrain mechanics o Best drivetrain for your team o Maintenance

3. Ideal Drivetrain Gets your robot where it needs to be, when it needs to be there Is robust and reliable Can push/pull objects and other robots Meets your strategy goals Fits with the game Can be built with your resources Rarely needs maintenance Can be fixed quickly

4. Basics Know your resources Decide after kickoff: Speed, power, shifting, mobility Use the most powerful motors on drivetrain Don’t drive ½ of your robot… WEIGH IT DOWN! Break it early Give software team TIME to work Give drivers TIME to drive

5. Wheel Types: Traction Standard wheels with varying amounts of traction, stength and weight AndyMark KOP VEX Pro AndyMark Plaction AndyMark Pneumatic

6. Wheel Type: Holomonic Special Wheels that allow the robot to achieve Holomonic motion Mecanum Omni Crab Module

7. Caster, Omni, Slide Driven Wheel + Easy to design + Easy to build + Light weight + Inexpensive + Agile - Not much power - Will not do well on ramps - Easily turned Motor(s) Drivetrain Types: 2 Wheel Drive

8. Chain or belt Driven Wheels + Easy to design + Easy to build + Inexpensive + Powerful + Sturdy and stable - Not agile - Turning is difficult Motor(s) Driven Wheels Drivetrain Types: 4 Wheel Drive 2 Gearboxes

9. Drive Wheels + Easy to design + Easy to build + Powerful + Sturdy and stable + Many options: Mecanum, traction - Heavy - Costly Motor(s) Drive Wheels Motor(s) Drivetrain Types: 4 Wheel Drive 4 Gearboxes

10. Gearbox + Easy to design + Easy to build + Powerful + Stable + Agile* - Heavy ** - Expensive ** ** - depending on wheel type *2 ways to be agile 1.Lower contact point on center wheel 2.Omni wheels on front or back or both This is very common in FRC + simple + easy + fast and powerful + agile Drivetrain Types: 6 Wheel Drive 2 Gearboxes Check out 1114’s Kitbot on Steroids Simbotics.org Resources Kitbot en esteroides

11. Gearbox + Powerful + VERY Stable - NOT AGILE - HEAVY - Inefficient - EXPENSIVE - Hard to maintain For turning, lower the contact point on center of track wheel Sole benefit: Ability to go over things Will NOT push more than a well- controlled 6wd Drivetrain Types: Tank Treads 2 Gearboxes

12. Tank vs. Holomonic Tank Drive 2 Degrees of Freedom Rotation Forward-back Motion Holomonic Drive 3 Degrees of Freedom Rotation Forward-back Motion Side-side Motion

13. 4 wheel drive or 3 wheel drive + Immediate Turning + Simple Control – 4 wheel independent - No brake - Minimal pushing power - Jittery ride, unless w/ dualies - Incline difficulty Drivetrain Type: Killough

14. + Simple mechanisms + Immediate turn + Simple control – 4 wheel independent - Minimal brake - Minimal pushing power - Should have a suspension - Difficulty on inclines Drivetrain Type: Mecanum

15. http://www.youtube.com/watch?v=xgTJcm9EVnE Team 1346 Mechanum Drive

16. > Each wheel rotates to steer + High-traction wheels + No friction losses in wheel-floor interface + Ability to push or hold position + Simple wheels - Complex system to control and program - Mechanical and control issues - Difficult to drive - Wheel turning delay Drivetrain Type: Crab/Swerve

17. 368’s Crab Drive in 2010 http://www.youtube.com/watch?v=q9uck-wRa_8

18. Game dependent Determined by wheel size and gear ratios Controllable top speed: 15 ft/sec Average 1-speed rate: 9 ft/sec Good pushing speed: 4-5 ft/sec Drivetrain Top Speeds

19. Center of Gravity (CG) o Robot mass is represented at one point o Mobility increases when Cg is low and centered o High parts = light weight o Low parts = heavy (within reason) Which is more Stable?

20. Gearboxes/Transmissions Gear ratio determines top speed and motor load Single Speed and Shifting options CIMple Box shipped in 2011 KOP 1 or 2 CIMs per gearbox 2011 4 CIMs allowed Must be greased to reduce friction

21. Belts + Don’t Stretch + Can reach far - Need to buy in custom sizes

22. Chain Selection #25 + Lightweight + Easy to install + Smaller - Easy to derail - "Steches" over time #35 + Allows for slop + Minimal "stretching" + Heavy duty applications - More weight

23. Working with Chains Tensioning o Critical to keep robot from throwing chains o Must be accessible and easily adjustable o Does not need to be used on ALL chains but should be on drive systems

24. Look at other Designs! Competitions chiefdelphi.com Team websites YouTube thebluealliance.com

25. Presented by: Paul Hines John Hines Drive Types + Wheel Pictures www.AndyMark.com (FRC Supplier) Swerve Drive Revolution Custom Frame www.team221.com (FRC Supplier) Check out 1114’s Kitbot on Steroids Simbotics.org Resources Kitbot en esteroides