Usually you only use one power supply for the whole machine, although sometimes you can use a small separate one for logic-level signals if your main PS doesn't have a low-voltage tap. Why did you decide to use one for each motor? Here's what Masso recommends for the G3: https://docs.masso.com.au/getting-st...ering-masso-g3 It all seems a little underpowered for NEMA 34 motors, though. It's rare to find a 34 motor with low enough inductance to work well on 24 volts or less.