Mrambo motor squeel on one driver

Hopefully someone can offer some assistance, video attached describing and showing the issue.

X-Axis motor goes into a high pitch squeel after stopping motion (not normal motor whine) & loses steps

when swapping the cables on the x and y motors, the x motor moves and sounds clean, while the y motors show the issues above.

Using the Mrambo that came with the kit, pwm_motor_control is unaltered.

Hopefully that provides enough info for someone to help.


Is there an easy way to change in Marlin the motor pinouts, to effectively swap x with e? Using the extruder motor output it runs great. Just the x motor output seems wonky. I’m using the firmware linked off the main page, and the mrambo board was the one provided in the kit.

I wouldn’t worry about it. They all do that to a point. When my printer does it, I just jog it a couple mm, and it stops. I think it does that when it’s between real steps, the microsteps keep it between full steps and it vibrates in that spot.

You can swap the pinouts in pins_minirambo.h

Does it act any differently or just whine?

The motor vibrated excessively, caused the set screws to come loose, I secured them with some medium strength loctite.

I swapped the motor pins in marlin, and I’m using the E motor driver, everything works better now. guess I just got a partially bad board.

Thanks guys!