Interesting AM14U2 and AM14U3 upgrades

You’re welcome!
With 4" wheels, no; you’d have to go through the tread. It looks like 6" or 8" hi-grips should work; I’ll try a test of this in coming days. [edit]Yes, an 8" 2010 wheel has plenty of clearance, and AM’s drawings show even more space on the 6" and 8" hi-grips. Note that you need a 5/32" allen wrench about 5" long to reach all the way through; this is definitely longer than many. The only one I have which reaches is the Eklind 51610 which I purchased at the local Ace Hardware, but is also available from MSC and others.[/edit] If you turn the gearbox sideways so the CIMs extend upward, it is possible to remove the CIM screws and lower them through the access holes in the shaft plate, then re-insert them the same way. (In both cases, put one screw in/out halfway, do the other, and finish up the first.)

Thanks, this is what I was planning to do.

Also, the demo robot I brought. with my size 10-1/2 foot for scale. The versaframe channels are there as a “stub” to show how to attach VF to the chassis. Also made a good example for Curtis’ bumper and inspection talk. I also discovered that Home Depo’s piano hinge is highly compatible with the kit chassis and versaframe. OBTW, I’m considering making this into a gear runner, and at least mocking up a legal control system as an exercise in the art of the possible. I’ll likely switch to a bottom-access battery as I add stuff on top.

Note - in order to fit the CIM at the far left, I had to trim a bit from the outer sheet at that end. I trimmed all the way back to the outer row of holes, but I could have removed much less and have the motor fit, but I figured with a 9" span, I could make do with less material.

Not also that if you made this a bit wider (1.5"?), you could do a 4 mini-CIM drive.