yennb,
Refering to the location of the encoders, YES this can be a problem. When I first cncd my machine, I tried to leave the original encoders in place (on the axis itself); and what a disaster due to the backlash in the acme screw. I relocated the encoders to the end of the screw, and there is basically zero backlash in the toothed belt drive between the servo motor and the screw so it works very well.
Bubba |