[DaveL]

This is a great design!
I like that its compact, has a lot of power and uses a wide base of support.

Like others have said, mounting the CIMs to their faced plate is the tried and accepted way to go, but I like the way you are thinking.

I am a little surprised you went with omni wheels. My guess is that they won't have the friction to transfer the power of the CIMs during high acceleration. Changing to a tread wheel would fix that. If you are short on resources, build one module and mount it up front. Then independently power the non-steering rear wheels. That would be one fun trike. For more fun, add omni wheels to the rear so you can slide your turns.