Blues first try out had steel balls as skid pads in the opposite corners but it was hopeless to drive and kept getting stuck on the floor so we simply tried it without and it worked great so we left it at that. We (my brother ) had no problems in driving it with an IBC controller, but it does rock diagonally under acceleration and deceleration but it has not proved a problem.

Blue is now retired, and some bits used for a new robot with the same drive arrangement and finally CO2.