[Hitchhiker 42]

Originally Posted by Lireal

There axis of rotation of the ball would not line up with the wheels when both are spinning though. Here is a quick sketch of where it would be in relation to the wheels: https://docs.google.com/drawings/d/1...DOI4KIXro/edit

Looking at the picture made it clearer. I was convinced that, at least with a diagonal of 45 degrees it'd be fine. However, it seems even that would be a problem. Omniwheels, like others suggested, might be the way to go.