Also, just as a question to anyone who has a pushbot or a wedge on their machine, how much ground clearance is best for the RoboChallenge arena? The whole machine has quite a large amount of clearance at the back (it actually has a slight slant forward, so technically it's a wedge I guess) but it has some at the front still, not being flush with the floor - is it best to have a zero ground clearance or to have at least a little bit so it doesn't get caught on the floor panels?