Ok, old thread but what to do if we use direct drive via coupling from stepper motor to ballscrew
Ballscrew pitch 5mm
200steps (one revolution) = travel 5mm or 0.025mm per step.
1600 steps/rev will give travel 0.003125 per steps
Is this going to be ok for cut smoothness - final surface quality etc?

I personally always use gear not direct drive, however all the MC on my work place use direct drive but with servo motors which should not be compared to steppers.