The next obstacle was setting up the rod to move the Z axis. It was a difficult problem, since it needed to rotate but not move. After a lot of thought, I decided to drill and tap a 4-40 hole into the top of a thumb screw so I could constrain the thumb screw in he Z direction while still allowing it to rotate. That is what the hole in the bottom of the base is for. Once that was solved, all the mechanics were done.