Quote Originally Posted by Wobblycogs View Post
Possibly this is a silly thought but is it worth trying to getting the X and Y axis ball screws machined so that they can be used with a fixed BK bearing on both ends?
Not a silly thought and won't make it worse that's for sure but hardly worth the hassle has you'll have no problem with critical speed or whip at this length screw using steppers.

Regards the 4Nm then I've found the 3Nm motors spin faster and see very little to any difference in torque.!