Quote:
Originally Posted by Team1710
Yea I'll post an image of what I have currently. Also What type of wheels should be used in a crab drive? Right now I'm basing it off of this year's wheels but I doubt next year will have wheel restrictions.
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You're right to take that into consideration. In 2002 traction was everything and my team built a crab drive with 2 wheels in each corner. What's worse, we had a coefficient of friction around 1.6!. That thing could pull, but we were burning out our motors and stripping gears trying to turn. Taking off one of the wheels on each housing we were able to turn more effectively, still with a 1.6 uf. The wheels were off the turning center of the housings, though, and I'm sure that helped. We also restricted our major turning to when the robot was in motion, which does take away some of the advantage of crab.
The following year a similar design worked with the wheels in line with the turning center although we eventually moved away from the high traction material because it wasn't as necessary.
It's actually probably a misconception that you need low traction wheels in general for crab. If anything, crab allows you to have high traction on all wheels because the wheels don't have to slip sideways like they do in tank drive. You just have to keep in mind the force required for stationary turning, just like turning the wheels on your car when the car isn't moving.