[Mat]

Sorry about the response time, I tried to cut down on all the junk in the drawing so it was more understandable. Anyways this is my concept for external treads, in my case I was going to be using bycycle chain and sprockets for a tread system, so I figured that I could simply use the end of the axle, put it in a bearing and mount the bumper temporarily off that. If you are bumped hard you may risk damaging your axle, slowing your motors temporarily, and some other stuff but if you do it right there shouldnt be any issue. In my newer design I utilized 3 axles with an additional point in the midde. The other bumper just mounts to your robot normally unless you have treads on all 4 sides, so in my case I figured we would use our typical fastening system to get it on and off quick. For quick on/off times and ensuring the bumpers over the treads stay on I figured I would utilize lunchbox or toolbox style clasps to keep the bumper attached to the other. I can get you something more in depth or simplified depending on what you have a stomach for. Let me know if you need anything.

-Mat
Aztechs 157