paper: Killer Bees 2011 Robot CAD model

[Alex.q]

Sorry for reviving an old thread, but I was looking at your CAD and had a question about it. On the wheels, the hub that you use to attach the wheel to the axle is right up against the bearing blocks. How did you attach this hub to not need space for the head of a bolt to attach it to the wheel? Also, there doesn't appear to be anything to prevent the sprockets from moving along the axles (in the axial direction). Is this accurate?

Thank you in advance for answering my questions and more importantly thank you for posting your CAD.