Cut going off path frequently [Solved!]

I’ve been having a lot of trouble recently with my cut going off path and I’m not sure what it could be. Usually it happens around a corner. It’ll go 3 or 4 passes and then suddenly go off path, I think usually on the X axis (right to left). I’ve tried this cut 4 times with 1 success and 3 failures.

Things which I have checked:

  • Spindle upgraded to Dewalt 611 as I was afraid the 24v spindle was having issues
  • All belts are properly tight
  • All v-wheels and properly tight on the maker rails
  • Nothing seems shaky on the spindle mount or axes
  • Material is properly clamped down
  • There are no visible obstructions or knots visible that I can see - I am cutting 6mm MDF.
  • I am using a spiral upcut bit, and have the router turned up to the higher side of its speed capability due to paranoia
  • I am using default recommended feed and depth settings (1016 mm/min and 1.6 mm)

Below is a photo of the results, and here is my project file: http://easel.inventables.com/projects/yOSieDRKFbeIxQwuDvpnIA

Any idea what I might be doing wrong?

In the below photo (originally taken landscape) the spindle has gone off track on the bottom right (right upper side of the machine), while doing an outside cut of the hexagon, just after lifting near one of the holes briefly. I’ve noticed since there isn’t much clearance between the hole and the edge, it seems to make little mini tabs there to keep them from tearing out.

Maybe try adjusting the potentiometer to give it more current?

Check the eccentric nuts?

Are the set screws tight?

Good call on the set screws. I’ll check those on all the steppers.

Which pot do I adjust? Just all of the stepper motors? Should I just be testing with a multimeter? How do I know what the proper amount is?

It would probably be the Y from your picture.

If you have some scrap MDF you could try doing a circle and increase the federate to try and exacerbate it to see which axis is skipping then turn that pot up a 1/4 turn and see if that fixes it.

I made a couple videos about X-Carve maintenance, which include potentiometer adjustment, calibration, and belt tensioning. Maybe the pot adjustment video will help you get them dialed in.

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Thanks Robert, that is helpful!

For working the Z axis, I might create a design with 100 holes or so, set the cut depth to an inch or something and have it plunge those. Alternatively, it should be possible to make a set of *.gcode files to work the motors in the various directions. If I end up making some, I’ll pass them along!

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Reporting back:

Thanks for the suggestions! After adjusting the potentiometers as indicated, everything works perfectly! While I didn’t end up making a custom G-CODE for configuring it, I found it easy enough to do with Robert’s method using Easel.

My CNC is a Straight-A honor student now!

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Excellent, it’s so much more fun to play with the X-Carve when it does what you want it to! :smile:

I had the same problems when I first started and found @RobertA_Rieke’s videos extremely helpful. He was also very personable in answering a few questions. Kudos to you again Robert for all your contributions here.