I'm building my first CNC tool: a small lathe with 2 steppers. I decided to use a Kflop/Kstep combination. Now I'm looking for a power supply.
I would like to be able to run up to 4 570 oz-in steppers off this setup, because I may want to add another machine later. For that reason, I want the power supply to be bigger than the lathe requires. Obviously, I would not be running both machines simultaneously.
The 570 oz-in steppers are rated at 5 amps. I have seen various references saying I will never need more than 2/3 of the maximum rated current, so if that's true, I should be fine with anything over 13.33 amps. But someone on a forum is telling me the steppers will draw maximum current all the time, so I need something that will provide at least 20 amps. He says the torque will be derated if I go below 5 amps.
Is he right? I know nothing about CNC, but it seems like everyone disagrees with him. I have read that you don't need max current for microstepping. I found a power supply that will put out over 16 amps, and I was thinking I would go ahead and buy it.