Quote Originally Posted by dazp1976 View Post
If I did it again I would get drivers that are rated upto 80Vac/110vdc and use a 70Vac toroidal transformer.
Something like a 2*35vac secondary outputs wired in series for 70vac.
Doesn't matter wether you have Nema 17/ 23/ 34size motors etc, the drivers regulate output voltage to the motors themselves.
That's WRONG information your giving out, the drives don't regulate the voltage they regulate the current. 70Vac which is 98Vdc would destroy those little motors in no time at all. It would also make them run like a bag of shite.

You cannot stick any voltage you like into a stepper, there is a limit where it starts to have very negative affects. Namely iron losses and motor heating which kills them.

Those Large voltage Ac drives are only really any good for larger steppers Like Nema 34 or very high inductance NEMA 23's. Your typical 3-4Nm 4.2a Nema 23 with 3-4mh inductance doesn't like to be run much more than 80vdc and at that, you are pushing them past there design threshold so are shortening there life.

For the NEMA 23 motors, which this machine will have fitted he'll only need drives with a max rating of 70Vdc and would run them around 55-60Vdc. Or 50Vac drives running at 40-45Vac.