For our second bot ever, we are attempting a holonomic with casters on the corners to keep it stable when we use our lift. (how can casters keep anything stable one might ask…)
Team 1189 is using a 6 WD design with the 8 in. Andy Marks performance wheels. We’ll be using 4 CIM motors and super shifters to provide power.
This year will see the Capitals running an improved version of last year’s kitbot 6WD, reasons being:
a) We don’t have the tooling or the manpower to get all uber-fancy
b) A judicious application of AndyMark products met our needs,
c) We liked what we saw last year.
I agree with what others said about omni/caster wheels
omni and caster wheels are easy to push around. 6wd tank with AM 2 speeds for the win
6WD with omniwheels at the corners, as we’ve been doing for a few years now.
In 05 we only had 2 drive wheels in the middle and then we had 4 ball casters in the corners, it was a good design imo. We could turn on a dim and it just worked well.
Last year for rack and roll we use 6 wheel drive but our front and rear wheels were omni wheels and our middle were the standard wheels we got. This year the team (14 people 10 of which whoom has never done anything like this before) voted on 4 wheel with two omni in the rear.
We were going to try rack-and-pinion car style steering, but we figured that since we were so behind schedule we’d go back to tank steering. At least we still have the maneuverability necessary to align with and pick up a trackball…
Just out of curiosity (it’s my first year at FIRST), what are the benefits of six-wheel drive train over four-wheel? And what’s omni-drive?
Omni-drive is the ability to go any direction without turning. Two classes are swerve (turn the wheels) and holonomic (non-turning wheels with rollers on them).
6WD vs 4WD is a little harder. 6WD doesn’t bounce as much as a 4WD while turning. However, the exact benefits depend on the type of 6WD–dropped center, coplanar, and coplanar (omni-in-the-corners) have their own quirks and disadvantages, but all have their advantages.
We usually go with 6wd, but decided that there wouldn’t be enough contact this year to justify the weight.
2wd using Dewalt gearboxes on CIMs - in the center with 6" dia 2" wide IFI traction wheels. Ball transfers on the corners 
Basically a VERY fast modified version of our 2004 drivetrain.
Similar to years past, RUSH is using a 6-wheel configuration. Unlike last year we have gone down from the 8 in. AndyMarks to the 6 in. Also, instead of using omni-wheels to reduce friction when turning we have placed the center wheels 1/8th in. lower on the chassis.
i think that a simple tank drive is gonna own this year.
We (teem 1225) are using a front weal drive system with two casters on the back. it werks rely well.