L.O.L. I think I made a funny. Seriously what are the advantages of a driven nut? I toyed with ideas of just putting a nut into the center of a pulley and adding a cutout to the center of another and there I would have it. Can one save space with it or gain stability in the lead screw? Just curious.
Sometimes it may be adventatious in a Design solution.
The main reason for using a Driven Nut Design is to eliminate Screw wipping wich can happen when a Screw is driven at high RPM's.
The longer the unsupported length of a Screw the lower the Rpm has to be to prevent this.
The larger the Diameter of the Screw the more it will be able to resist wipping.
A Driven Nut eliminates this problem because the Screw will be Stationary so
no wipping can occure.
Back to the humorus side: A lot of people have been driven Nuts by there wipping Screws.