So, getting very close to a working module. The 1/8" cross section o-ring on the final drive shaft is going to have to be changed, as the action is rather intermittent right now, (it slips) but it does work. The simplest change would be to go to a 3/16" cross section o-ring, and tomorrow I will try that. It is a very interesting little project. I won't build the transfer cart and the rails until I get this drive working okay.---Brian