Controlling a milling machine motor

Hi! I am powering the x axis of a round column milling machine. I am wanting the milling table to go left to right, right to left and at a controlled slow and a fast traverse. I am aware that the stepper motor will allow me to control a precise stop position. I have built a 24v DC variable speed and direction control system for a 24v motor that I have but am wondering whether a stepper motor would be a better option. Could you please advise me whether a stepper motor would be a good idea over a conventional DC motor and what control method would be required please. Thanks! Bill.

Hi Bill,

Generally in my experience, steppers are nicer to work with than plain DC motors, but require a bit more effort to drive.

Take a look at this video from This Old Tony explaining stepper motors in the context of CNC:

As for simple controls, a microcontroller like a Raspberry Pi Pico can generate step and direction signals based on button presses or potentiometer inputs, and more (Perhaps an adjustable stop you could put on a jig?)

From there you’ll need a stepper driver powerful enough to drive the large stepper (NEMA 34 motors find their way onto CNC machines often), these can draw around 6A depending on the manufacturer, so make sure your stepper driver can handle that. This is the largest one we have to my knowledge, so if you know a smaller motor would meet your torque requirements, that might be an idea.

Are you driving the axis directly? or through some reduction?

Could you send a photo of your current setup so we can take a look at what you’re trying to replace?