Using a car screen wiper motor, that I totally wrecked, I tried to make a dome drive system. I used a rubber wheel and a wooden frame. I hooked it on the rods that are supporting the frame, attached a spring to it and made sure that it did make good contact with the rockler bearing. It worked! Unfortunately the axle of the motor was threaded ( like a screw ) and therefore the wheel was not entirely vertical. SO I took the assy out and wil try something else.
What did work was the RC unit I took from a RC car. It has a transmitter and receiver, 12V batterypack and 2 relais. I will be using this for the feet driving, to play with, untill I will buy more robust and professional equipment.