Re: pic: 4143 differential swerve concept
 

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.

Re: pic: 4143 differential swerve concept
 

Do your thoughts on overall plausibility change if a non-standard wheel configuration (e.g. 3 pods in a triangle) is used?

Re: pic: 4143 differential swerve concept
 

Interesting design, one thought though:

Assuming FIRST keeps the same rules that they have the past few years, in all likelihood there will be a limit of 4-6 CIMs on a robot which would make this design as shown illegal assuming 4 wheel swerve. That said, you could just swap them out for MiniCIMs.