I found the solution to how the rotating cylinder works to be very self evident. The system only needs rotation to work. So even if only rotating the sleeve, it is still mechanically exactly the same as rotating the screw.<br><br>Another way to think of it is this. Lets say I want to drive a screw into a piece of wood. So I start out with a screwdriver to drive the screw into the wood. Then, after the screw is part way into wood, I stop screwing. At that point, I decide to put the screw into a vise. I then rotate the block of wood. As I do this, obviously in the proper direction, the screw is driven further into the wood.<br><br>Why this sort of thing baffles people is a mystery to me.