[RyanShoff]

There would be not a differential, just two cantilevered wheels. All the comments so far are spot on. A higher friction pivot bearing would help. You would probably want 3 encoders, but maybe just one would work. The control loops are real interesting. I was thinking you could have one module with minicims to get around the cim motor limit.

One idea no one talked about is putting something like a caster angle into the modules. You could shift the wheels back slightly from the centerline of the pivot. The advantage being that they might track straight easier. The disadvantage being reversing direction would need a 180 degree twist.

This was mostly a modeling exercise, but with some development, it could be a viable drivetrain.

Step files coming soon.