Nice and light; too bad it'll never see the light of day. I'm looking at GrabCAD right now, and I have some questions.
Is it worth it to machine a rim onto the custom wheel if rivets on the tread already hold it on?
How is the bevel gear attached to the wheel?
For the 4 little spacers/bearings on a bolt that help hold the 72t turning gear onto the main plate, do they do anything the delrin groove ball bearing doesn't do? I guess they could just be helpers, but I can imagine that tiny bearing breaking if it has to take the whole weight of the robot.
On a side note, I have no idea why some of your bolts have blue threads.
