Quote Originally Posted by dazp1976 View Post
Steppers are generally all rated 2-3Vdc yes?.
My understanding is that if you give a coil on the stepper the rated voltage (2-3V) it will draw the rated current.

If you give a stepper a higher voltage, the current will also increase and the thing will burn up.

But we're not doing that - we're using stepper drivers. These give the motor the full voltage in "punches" to limit the average current to a set value. Therefore its entirely reasonable that the voltage supplied to the driver is important for the reasons Jazz sets out.

Blanket recommendations are dangerous either way - you need to consider all the factors like the steppers inductance and current limits to determine what will blow and what won't. NEMA 17 or 23 is just a mounting size, and has no real effect on this.