Laser shifts by 1/4 inch in the middle of the cut

I’m making a sign, and midway through the engrave (on proofgrade maple) the laser just … shifted … and started cutting the rest of the design 1/4 inch ish over. The table wasn’t bumped or anything.


The design looks like this:

I haven’t the foggiest idea what to do next (but of course need to be able to cut approximately a zillion things between now and Black Friday.)


Before staff gets here, there is one of two things most likely going on. One, and most likly, you have a weird little problem with the file. You can check this simply by printing something you have printed sucsesfuly before.
Second posibility is you have had a belt slip, if it is just a bit lose and there is no damage staff should be able to tell you how to tighten it up and all will be well.


Thanks for the suggestion, I did a test cut of a small thing I have cut a large number of times; the top is what it should look like, the bottom is what just happened.


Yeah, that looks like something mechanical. You need to inspect the belts, the wheels, and the tracks closely. Make sure there is no debris on any of it, and that the belts are fairly snug and clean. (Resin buildup on the beds and wheels can cause that to happen - the belts will start to slip.)

If you need to clean the belts and wheels, you can read through this post to someone with a similar issue:


Many thanks, Jules. I’ll give that a try after I stick some food in my gullet, and report back with results or questions.

If you don’t hear from me, I assume it will mean I’ve gotten trapped inside the machine itself, a la Tron…


Okay, the good news is that it is your X drive belt that is slipping, it is the easy one to get to and there is only one, there are two Y belts making things more complex.

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It’s behaving again! Thank you both so much for your help.


Good deal but if it starts acting up again look at the X belt and drive. That is the one that attaches to the head.


I’m so sorry your print didn’t come out beautifully.

Can you try the following test for me:

  1. Turn off your Glowforge.

  2. Wait 30 seconds.

  3. Turn your Glowforge back on.

  4. Print the Gift of Good Measure using the default settings.

  5. Place the design it as far to the right as possible

  6. When the print finishes, leave the lid closed and wait until the fans stop and the picture updates. Without moving your artwork or your material, take a screenshot of the Workspace to show us the difference between the artwork placement and the actual print placement. Make sure to include the rulers in your screenshot and show as much of the bed as possible.

  • Mac: Press Shift-Command-4 and click and drag a box around your image. You’ll find the screenshot file saved on your desktop.
  • Windows: Click on the Start Menu and type “snipping tool”. Open the Snipping Tool > New then click and drag a box around your image. Click the Save icon and name and save your file.
  1. Send us the screenshot along with the date and time of the print, and we’ll investigate.

I’m going to throw out a third option (because I’ve had this happen): You had the board either way forward (next to the front) or way to the right. In either case, the head bumped the wall and caused the shift.

I have tape on my crumb tray marking 1.25" from the front and 1" from the right. Those are head-bump zones – avoid them.

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Hi Pip, thanks, and also thanks to dr.krawetz, markevans36301, and especially to Jules. Pip, everything is working fine now, so I’m going to forego your suggested steps for now.

Mark, you were correct that the X drive belt was the problem. I cleaned it following the instructions Jules linked to. Of course, I misread the instructions and also ended up partially detaching the right Y belt…

I’ve done several cuts and engraves since putting everything back together, and they’re coming out beautifully.


I’m glad you resolved it! I’m going to close this thread. If you run into any other trouble, please start a new topic, or email us at We’re here to help!