Two HXT900 servos modified for continuous rotation do the driving. No controller or sensors yet, just a simple servo tester used here. Servos are driven in opposite directions, so it just turns in place. More to come.
"When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."