[petek]

Looks like a very open design - lots of room to move things around or make changes.

I vote for the 2-speed tranny. That was one of the keys to 103's success in 2005 - it was geared for about 6 fps and 14 fps (which was great for banzai runs to the opposing home row!).

Did you couple the speed encoders to the axle with flex couplings? If not, I strongly recommend you do - the Greyhill encoders don't take kindly to side loads on their shaft bushings, plus it's just good engineering practice. That way you don't have to be quite so precise with the axial alignment.

Nice Inventor work, too!