John,
You don't really need the 1.5K resistor. The series resistor (shown as 10K), serves to limit the current. I haven't checked to see if 10K is appropriate for the optoisolator you are using, but it is probably about right.
On the subject of power supply regulation, I don't believe that it is necessary for this application. The voltage affects the servo speed; not the torque. That's controlled by the current. If you are worried about achieving a certain maximum speed at maximum load, just use a higher supply voltage. In practice, though, maximum speed will occur when traversing at no load.
I could imagine that poor regulation could affect the servo tuning, but in practice, tuning is not that precise, anyway. Other things like varying part mass, material, depth of cut and so on have a much more significant effect.
Ken
Ken
Kenneth Lerman
55 Main Street
Newtown, CT 06470