Some of you asked for a closeup of the differential created by Steve H. Well, here you go...
(Photos of detailed parts are difficult... sorry if these aren't what you asked for, but they were the best I could get with the camera I was using.)
CORRECTION: These closeups are from a bot built by Bryan... the differential is slightly different from the one built by Steve. Sorry for the confusion. I didn't have access to the original differential on Steve's bot to photograph...