Laser arm going crooked/loud sound when powered on/homing

My Glowforge Pro was working fine last night, but today it will not function. I did not have any problem with my last cut. When turned on and attempts to home, it is much louder than normal & the left side of the arm seems to be moving faster than the right side causing the x axis to go crooked/near derailing.
For trouble shooting, I have already checked for any debris in the belts (or anywhere), cleaned dust/soot off the tracks, used a 12" rafter square to square up the laser arm, sprayed compressed air into the belts/left side of laser to dislodge any potential debris issues, checked for loose belt screws, nothing is visually off. The laser arm is moving freely while the unit is turned off, but the arm still makes a louder not-normal sound and goes crooked on the rails after turning it on. The picture attached is how it is returning/finishing homing.

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Have you checked your wheels for any cracks/breaks?


All the wheels & teeth look normal. Also just did protocol for belt tension and those are even.

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It’s really rare for a stepper motor to malfunction, but possible. My first guess would be an obstruction, but you said it rolls smooth when off. Next, I would inspect for a wire snagging on the right side. A cracked wheel might do that I suppose.
Anytime I have seen this it has been material obstructing the gantry or a hose or wire catching somewhere.


Remove the honeycomb tray and open the front door so you can look underneath the laser arm as you move it forward and back. There is probably something snagging.



heres a video of the hoses/ wires. is that red one supposed to be dragging the way it is?


this is the video that resulted in the picture above, you can see how hard it jerks at the end that throws the whole arm crooked. Thank you all so tremendously much for any thoughts you may have!


No. That wire dragging is not right, it will eventually wear through. I would inspect the red insulation for wear, take a zip tie, and position that wire so it doesn’t rub, This problem is unassociated with the gantry skew on the right side. BTW, good job on the videos! You should send those to support.
I couldn’t tell from the video, but you shouldn’t physically move the gantry or the head when the machine is on.


I have the same issue only my machine is brand new haven’t been able to make a single cut

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Note: This is only an issue with the Pro machines, due to the heat sink at the back on the left.

It can be caused by a cable with too much slack in it under the gantry getting hung up on the fins of the heat sink when it homes.

To check for it, you need to turn the machine off, drop the front door, grab a flashlight and get down so that you can see underneath the gantry on the left side. There is a red cable that runs the length of the gantry, you can see it through the tube if it’s clean…locate that cable, keep your eyes on and slowly push the gantry back to the rear. If you see the cable catch on the fins of the heat sink or feel any resistance, stop.

Instructions to fix it:

jaz Staff
(edited slightly for clarity)

Aug '18

Thanks for posting. I’m sorry about the trouble here.

I have a fix you can try that should stop the tube from getting caught.

  1. Unplug the machine. Using two hands, gently roll the laser arm to the front of the bed
  2. Look under the right end of the laser arm to locate the red wire cable.
  3. Slide the wire gently towards the right and back of the unit to shift more of it from the left side of the laser arm to the right side. (You can straighten it out and feed from the left side as well. Do not pull hard on it.)
  1. Plug the machine back in, return the head to the Home position, (upper left corner of grid). Turn on the machine, and let it run through the Startup Calibration sequence.

Once you’ve finished, the wire should stay in place. If that doesn’t work or if you encounter any issues contact Support and tell them what you did.


I don’t have any helpful solutions as I am relatively new as well and just wanted to say that I empathize!

Thought I would share the resolution of my issue, since other related posts didn’t have the follow up- maybe being aware of the full process can be of use to others in the community.

I tried every possible trouble shooting route on my own, including:

  • checking heat sink/all wires from catching

  • a really deep clean for search & rescue of ANY mysterious debris lodged anywhere

  • protocols for checking all belts, wheels, and tracks of any cracks or obstructions

  • squaring up with a rafter square

  • general crying, screaming, bargaining with the laser gods, gnashing of teeth

For my support ticket, they asked me back & forth a couple things to check (all of which i had already done, except a test cut). The test cut was painful to watch, I’ll include a photo. I eventually got the “it’s unrepairable remotely.” response. I expected to send it in for repair (seemed like a $500ish bill from what other people had said) but I was told my only option was to pay $1,125 to have a refurbished printer sent to me, and I send my original printer back (permanently) in the refurbished box. It ended up being $1205.44 after tax.

I paid the invoice right away to prevent additional downtime & recieved the refurbed machine only 2 days later, so that’s something less soul crushing to celebrate in this whole disappointing affair.

My Pro is only 18 months old with very light use (only daily around christmas, the rest of the year like once a week). I have taken meticulous care of it, read every resource/post possible to prevent damage and now I have a machine that God only knows its level of used/abused/aged/traveled.

I have only ever cut basic ornament shapes out of baltic birch wood (under 2000 hours, with no other material or engraving at all except a few tests, so i find it ludicrous that it had a total failure only 6 months out of warranty.

The thing I find most frustrating (besides the $1,205) is that i’ll never know what happened to my printer. Why was it perfectly fine when I went to bed & never functioned again the following morning? Was there something I could have prevented, even thought there was no event/broke while off? Was it just a total hardware fluke and if so, why are machines priced this high having massive malfunctions with only a measly 12 month warranty? it just really sucks, and it made me do a LOT of thinking about my future investments into the glowforge brand.

I have been waiting to really ramp up my business until I was ready/sure I wanted to get a second Pro, because I didn’t want to be reliant on only one machine when I had a ton of open orders at the mercy of multi-day waits for any support. I saved up & was ready to buy my second one the same week my Pro had a total death, so I guess that’s a sign to reconsider lol.

If you would like to speed up your support tickets for the same issue, maybe you can load this information into your opening support request (to prevent some of the back and forth for days- I responded within minutes of every email, but it took 24 hours to get a reply each time):

  • serial number on back right of machine

  • turn off your Glowforge, remove the crumb tray and take photos of the laser arm wheels on both sides (4)

  • a video of the problem (make sure if using google drive that you grant access to each video before sending)

  • “is the problem limited to certain times of the day? Is it in any direct sun?”

  • main request: “could you run a test print for me? The design we use has some known dimensions built into it and it will help me extract logs afterward to take a closer look. Here are the steps for the test:

  • Print the Gift of Good Measure on Proofgrade Material, using Proofgrade settings.

  • When the print finishes, leave the lid closed and wait until the fans stop and the picture updates.

  • If the Gift of Good Measure fails to print as expected, take a photo of the front and back of the print and attach these photos to your reply.

Hope this info helps future forgers searching for info to help themselves! Cheers.


After only having my GF since February I started having the same issue this weekend, I detached both belt and the laser arm runs unimpeded in both directions. I inspected both belts and the stepper motor sprockets all are in serviceable condition, Since it seemed to cock in the same position as shown above I swapped belts just to make sure that it wasn’t a belt. With both belts removed I made a paint stripe on both stepper motor spools. Videoing each side as the machine went through a power up the spool on the right the paint mark did not move which tells me that the gear in the spool is stripped or the stepper motor is not operating properly. The spool on the other side ran just fine as you could see the paint mark going around in circles. Th pic is my machine after a power up, The two videos show the stepper motor sprockets as I can a power up. I left the right-hand belt off and the machine powered up flawlessly.

After reading all the comments on the dismal customer support I am having buyer remorse issues. There is nothing more irritating than spending over 6K for a machine only to hear from owners that support is pretty nonexistent. So I will try to find the parts and fix the machine myself.

Watch both videos you will see that the right front stepper motor sprocket is not turning.

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