1. Proposed Dewbot V Chassis Clem McKown Team 1640 December 21, 2008

2. Why 6wd? This summer’s prototyping and follow-up analysis demonstrated that 6 wheel drive robots have a significant advantage in maneuvering vis-à-vis a 4wd robot Omni-wheels facilitate 4wd turning, but make a robot easier to push around 6wd middle wheels are key for turning performance Also a plus for ramps

3. Good practices 6wd has no advantage in traction or stability, but… For traction, all wheels should be driven; robot should be at maximum weight; and traction tread material should be used For stability, Maximize wheelbase Keep center of mass low and central

4. The Specs (6) 6” AndyMark Plactron Wheels (4) CIM Motors (2) modified 2-speed AndyMark Shiftboxes 9.4:1 & 24:1 Overall Gear Ratios 14.8 & 8 ft/s maximum speed 24.26 x 30” wheelbase

5. Isometric View “Grease Guard” 1 / 16 ” PC partition to keep electronics compartment clean cRIO Controller Battery

6. Isometric View (showing Jags) Jaguar (PWM) motor controllers mounted on front panel

7. Front / Rear Elevations

8. Right / Left Elevations

9. Plan View

10. Plan View (Showing Jaguars)

11. Direct drive to Middle Wheels Middle wheels are direct, gear- driven from the gearbox Front & Rear wheels are slave- driven via chains & sprockets from the middle wheel Benefits Reliability Keeps motor & gearbox (and center of mass) low Weight savings

12. Customized (Team 1640) Direct-Drive AndyMark Shiftbox New front & back plates Sprockets replaced w/ 20 tooth gear Additional axle = wheel axle w/ 45 tooth drive gear Spacer bolts (now ¼-20) also serve as mounting bolts

13. Identical left & right drive units We could build & bring a spare

14. Design Performance Acceleration curves are with wheels slipping High gear provides adequate power for turning (enough to make wheels slip)

15. Weight Current Mass is 68.9 lb m, which includes Chassis w/ Drivetrain Pneumatic System up to & including Regulator Panel mounts for electronics Battery Mount cRIO controller with: cRIO w/ 5 modules Alalog bumper Pneumatics bumper Digital side-car & cable Distribution Block Radio Does not include: Jaguar (PWM) Motor Controllers Battery Bumpers (not the electronic bumpers) Oh, yeah, whatever we actually need to play the game

16. Center of Mass 4.4 in above grade 4.5 in aft of chassis center (w/ battery) 1 in left of chassis center (w/ battery)

17. A reminder This is a still work in progress Any suggestions or critique will be appreciated