Matt:
You would have to call this Yankee ingenuity ! How smooth is the action/movement?
Nice job.
Randy
It's pretty smooth. The top portion is made from a cut down steel bicycle hub, with a cup and cone ball bearing at the lens end, and a bronze bushing at the other. The axle is just a 3/8 inch bolt, and tension is achieved by tightening the clamp as a nut.
When I ran over my tripod a couple of years ago, and broke the clamp on the ballhead, I rethreaded it, and it now has a stud whose hole goes all the way through to the 3/8 inch mounting stud. So once the drag is right, I can sock down that stud, and lock it in place.
It all would have been neater if I'd been able to weld aluminum, and if I weren't so farsighted that my welding is often in the wrong place, and ends up pretty messy. I used a Mig welder, but in retrospect I probably should have brazed it.