Controlling Big Stepper Motors with Raspberry Pi

Hello,

I am fairly new to the world of stepper motors, drivers and RPis, so I might have some potentially naive questions.

Firstly, I am using two NEMA 34 stepper motors and planning to connect them with DM860T drivers . However, I am unsure if I am able to connect these two, big drivers to a single RPi, or will I need two Rpis. Is this possible? Can a RPi work with this setup? Are the drivers too high voltage for the RPis?

I have seen many tutorials for small, single motors, but little resources for big stepper motors.

Any other assistance or advice will be greatly appreciated.

Thank you most kindly for your help.

I will also apologise if this is in the wrong forum page. In that case, could you please direct me to a more appropriate place?

You will need a buffer to convert the RPi 3.3v GPIO output to the 5v required by the stepper driver.

On a previous project I used a 74LS540 as a buffer between the 3.3v logic & 5v required by the stepper driver. Or you could use a simple transistor as a buffer.

The inputs to the stepper driver are opto isolators, so it doesn't matter what voltage the steppers run at. This is shown on page 6 of the data sheet for the DM860T.

BeagleBrainz wrote: You will need a buffer to convert the RPi 3.3v GPIO output to the 5v required by the stepper driver.

The stepper driver inputs might well work OK at 3.3V. It depends on the input resistors. all I see the current spec, at 10mA.

If 3.3V s enough to light that LED then it should work.

A single Pi can control many steppers, and does not care how big they are.

The datasheets mention a 270 ohm resistor, and also there is a quick mention of a 4-5v input.

Knowing the forward voltage of the LED in the opto would help in giving a definite answer. With 3.3v the max forward voltage that would make it happen is 1.4v
(This is based on me being able to math today)

An educated guess would be 3.3v not be an option.

Low-side switching might be an option, though apparently the Pi IO pins drive fairly hard to 0V and 3.3V, so IO-high might not turn off the LED.