Ramps - Stepper motors lock with pitch noise

Hi folks,

(This topic disappears right after I submit. Just trying again)

Just finished the build and run some tests to check if axies move properly. But steppers start creating a high pitch noise and locks down. There I saw several posts regarding this issue but none of them is with the Ramps configuration. Let me summarize the issue:

Control via LCD

  1. Run X axis > works
  2. Run Y axis > works
  3. Run Z axis > pitch noise + steppers lock
  4. Have to reset
Another scenerio:
  1. Run Y axis > works
  2. Run Z axis > works
  3. Run X axis > pitch noise + steppers lock
Video: https://streamable.com/tybuc

So basically what happens is when I try to move the third axis, system collapses

Repetier Host with Crown gcode

  1. Plug board to computer (Mac in my case)
  2. Plugin power supply to outlet
  3. Upload and run gcode
    1. Runs to same issue
  4. Disconnect and connect back to reset.
Video: https://streamable.com/g0uuj

How can I overcome this issue?

My electronics:

  • Arduino Mega - Clone
  • Ramps Shield v1.4 (Elecfreaks) - link
  • Stepper Drivers: Pololu DRV8825 High Current - link
  • Stepper Motors: Nema 17 ST42STH48-1504A - link
  • Power Supply: 12V-5A Switch Mode Power Supply
  • Serial connection: link

Those alligator clips might not be passing high current from the power supply very well. Current draw from the motors could cause voltage drop, which if it is low enough causes the arduino to lose its mind.

Check the voltage on the ramps side when the condition occurs, or just wire it better and see if it fixes it.


Have you set the stepper motor drivers vref and if so, to what voltage?

Maybe it’s just an optical illusion from your camera but from the top down pic of your machine the bottom right corner looks way out of square. If it’s truly that out of whack it wouldn’t surprise me that your motors get them selves into a bind.

I noticed that too, but earlier in this post he says he’s able to move both both x and y so I chalked it up to an optical illusion. It’s when he runs any 3rd axis (after moving the other 2) that the lockup occurs, is my understanding.


I changed the alligator clips with stranded copper cable and it directly started working as it supposed to be!

Thanks for your advise mate! Cheers!

It already passed half an hour since Crown drawing finished and left the machine plugged in means voltage.

Now I made a temperature measurement with my multimeter and it shows 80C degree.

It is really not possible to keep your finger on the heat sink.


Is that normal?

Yikes that's not good. Practically, running excessively high current can push the stepper drivers into thermal shutdown, which can be catastrophic if you are running a powerful tool.

Go through the steps to set your motor current properly.