[cbale2000]

I actually thought of making a drive system like this, but doing it with traction wheels and have one set actuate up and down to change directions, a bit like some of the octocanum and similar drives do, but with the entire drive module (the benefit being you'd have a sort of omnidirectional drive system with traction wheels).

Eventually I concluded that the system would weigh too much, use to many motors, and be too complex to be practical. That said, it would be cool to see someone make it work.