Quote Originally Posted by JAZZCNC View Post
I think you may want to reconsider the width of the gantry and make the bearing spacing wider.! . . .That looks awfull narrow for a single ballscrew design making racking a big possibilty.?
Everything what Jazz said plus I would insist two ballscrews. It is worth to invest a bit more ££ and have machine free from any distortion/ racking. You may regret one ballscrew some day.
One stepper per ballscrew, perfectly one stepper with its own driver but I run my machines with one shared driver per two parallel steppers on X axis and never had any problems with this at all.