Re: Power Supply to drive 2 Nema 23 4.2 amp motors
The maximum input voltage is not determined by the motor (they are rated around 3 V or so), but rather by the drive maximum rated voltage. The motor current is really the important value. The drive will limit the current to the motor according to current setting on the drive. So if you have an 80 V rated drive, then you're very safe operating at 75V, without regard to motor voltage ratings.
To be completely on the safe side, you could just add all the motor currents together and use that value for the power supply amp rating. I do tend to over build sometimes and 60% of that would probably work. But power supplies are cheap.
Closed loop steppers are the latest thing, I assume they work as advertised and should eliminate lost steps.
I have not used any of the integrated drive motors with the exception of the Clearpath SK motors. The Clearpath motors worked very well, but they are a bit more expensive than the import units on EBay.
The down side of the integrated drive is if you lose the drive or the motor, then you toss the whole assembly. The upside is that there is less wiring to deal with. In general I prefer a separate motor and drive.
Jim Dawson
Sandy, Oregon, USA