[Alex.Norton]

I was actually worried about how to keep the tubes in alignment. I was thinking of adding some sheets to the frame that would brace between the tubes vertically. And now that you mention it that is another good reason to use four motors, there is again less precision needed. While I do need precision to attach the motor mounts, I can think of an easy way to do that.

In this case since the module turning comes down through the top I can't run the wires through the bearing. I would run the wires up the inside of the module and then leave a large loop of wire to allow for turning before attaching directly above the module. I would also limit the turning of the module to keep the wire from tangling.