I've seen a few designs where stepper motors are indirectly coupled to acme or ball screws with a belt. Why is this done?
A half hour of searching didn't turn up anything helpful.
One rotation of a directly coupled stepper results in one rotation of the dreive screw. With a belt, one stepper rotation results in say, 1/4" rotation of the drive screw. So is the belt intended to increase the precision of the machine? Or is it done for greater simplicity and efficiency?