[Al Skierkiewicz]

Aren,
Don't forget some form of bearing surface at the bottom of the module. Between the torque from the wheels and the side load from a pushing opponent working on the moment arm of the entire module, the modules will bend and flex. Although it doesn't seem like much, it can put the wheels on edge which will lose a lot of friction and steering accuracy. If you remember, we have a circular plate on the module with a circular delrin bearing turning inside a fixed mating plate attached to the bottom of the frame. In the past we have used a variety of things, but the delrin ring seems to work the best when we choose to use crab drive.