Quote Originally Posted by JAZZCNC View Post
No this isn't a good idea. While in theory and practice it does works it gives problems due to the way drives work regards handling midband resonance. Modern drives compensate for mid band resonance and apply correction, problem is the correction only happens on one motor but at same time forces the other motor into resonance so it's a bad idea and often results in lost steps and crazy weird shit happening. (If 2 motors sharing one drive)
Also then there's slight timing differences and if your lucky enough to run the motors in range where you avoid resonance the timings can slowly run the machine into loosing positon and racking etc.!
I'm not saying to connect two motors to one driver, but rather connect two drivers to one step output. The aim of a slaved axis would be to provide two identical step pulses anyway, yes? There's no feedback from the driver to the controller anyway, so it can't possibly adjust more synchronized with separate step pulses than with two parallelled identical?