Quote Originally Posted by routercnc View Post
The other thing to think about is for an axis with double ballscrews you need to be able to square the gantry. This might mean being able to rotate one ballscrew very slightly by hand (without the pulley secured) until the gantry is square, so a key way or D flat would not work as this puts the pulley at a fixed location on the ballscrew. A simple pair of grub screws allows the pulley to sit at any angle on the ballscrew.
Shouldn't it be possible to auto-square using 2 drivers and adjustable endstops?