Slow Gradual Drifting of X Axis

Machine: Chinese Laser

Board: Cohesion3D LaserBoard

Firmware: Smoothie

Problem/ Question: Slow Gradual Drifting of X Axis. Have already slowed down speeds and accelerations as instructed on other posts, as well as upgraded hardware and installed external 4A drivers.
Is there another setting on the config.txt file that can be adjusted to address this? the drift is exponential.
Thanks in advance.

Can you please confirm what machine you have, and show how you have everything wired up, what settings you have changed, and what the drifted output looks like?

Hello, thank you for your reply.

Machine Webpage Link:


Config File:
config_2.txt (28.4 KB)

Screenshots (numbers represent speed mm/sec):

Really appreciate your expertise in getting this resolved.

Forgot to mention that last 2 images on right were optimized to reduce number of points.

Thank You

Additional example of X Axis shifting. See corners:

Thanks again for any direction in resolving this issue.

Which external drivers did you use? I’ve had some that also skip steps and did what you describe above. They’re definitely not all equal!

Make doubly sure that your motor drivers are set for the proper current as required by your steppers. The acceleration factor here will depend on this being correct (if it’s missing steps, it’s likely this, or a combination of the two factors - current being inadequate or too high, and/or acceleration being too high). I know you said you slowed things down and looked at acceleration, but it probably needs additional debugging in this area.

This is valid, I think he’s using the drivers from us but I’d like to be sure.

It is worth looking into whether steps are skipping, start by verifying what your motor model is, how much current it wants, and what you have configured on the DIP switches on the external drivers. Please provide that information here.

If the machine came an M2Nano style board and no external drivers (assuming you installed the drivers yourself), you should just be able to plug the X and Y motors into the LaserBoard itself (each motor output has a screw terminal to make this easy for you). For this application just increase the alpha and beta motor currents up to 1.2 amps and have at it. This is pretty much a “let’s cut to the chase and see if the external drivers are causing the issue or not.”

This is a difficult issue to track down and I have a very limited data set to work from, so will appreciate all the info you can provide.

Thank you both for your input. I will bypass the external stepper drivers and report back with results.

Thanks again.

Success! Bypassing the external drivers worked! These Amazon purchased stepper drivers failed me.
I’ve already placed an order for Cohesion selected and approved replacement drivers.
Thank you so much for your support. Great products and support.