Calibration Grinding


I know this is a topic that’s been brought up many times before, but I’m having this issue now as well. When I turn on my Glowforge, it often starts grinding against the left instead of moving toward the center. When this happens, I can reliably turn off my Glowforge, gently move the laser to the center and turn it back on, to have it continue calibration correctly.

I’ve read that ambient light sometimes confuses the calibration, however, I’ve had this happen in a pitch black room as well as lit from above (garage fluorescent lights).

I just don’t want my beloved machine to damage itself, so if there’s something more that I can do to end this, any help would be appreciated. =)


I have seen the head tap the left side 5-6 times at startup once or twice. I usually leave it alone unless I hear an extended grinding sound and have only had to manually move the head position once so far. If you were to leave it sit for a long time with it grinding that would damage the belts and or sprockets, but what I have seen should not affect the printer. If it does, it should be warranty covered in my opinion.

I tend to load material before turning on the GF so that may have something to do with it also.


I put a little stick-um bookmark where the tube needs to be, and one for the head to center under the camera. with the machine off, I position them there before starting it. Every time. It might save a second or two also.
It didn’t happen that often, but I couldn’t tolerate that behavior. :confounded:


Mine is doing the same thing… I’ve just changed my workflow to include positioning the laser head in the bed center prior to powering up each time.


-Turn off the machine
-Slowly move the carriage so that the Glowforge logo is directly under the lid camera

  • restart the machine

If the problem persists look at the carriage bearings make sure they are not cracked

Send an email with photo or video to Glowforge support staff


I’ve been moving the head to the center prior to turning it on to bypass the problem. The issue is we shouldn’t have to.


The problem is that the Glowforge does not have mechanical end stops - everything is built into the software

  • the camera needs to see the logo as a frame of reference to make its calculations for calibration

  • until they fix it in the software and have the print head end in the middle it’s probably good idea to just move the print head directly under the camera

  • you don’t want to burnout your stepper motors with that constant grinding


I’ve had it happen a few times. I do wonder what damage it causes to the life of the mechanical components. I’m a little surprised they haven’t fixed this yet. It’s been noted for a couple of months now.


In another thread a poster said over driving stepper motors doesn’t damage them so while the noise is unpleasant it isn’t doing damage. Personally, I try to remember and move my head to the upper right either after I turn the machine off or before I start it up. Glowforge really should issue a blanket statement about this and include it somewhere in the owner’s materials.

I once worked on a product that used stepper motors as pumps and they were always over driven to the home position. They never made noise. I assumed the engineers who had been working with them for years wouldn’t do it if they were damaging the motors.


Dan confirmed that as well.

I’m with you all though - I don’t like mechanical things grinding unless they’re supposed to.


Tritto here. Which is a new word I just made up. (Like ditto, but meaning +3.) :wink:

Mine has done it a few times. It’s been a while but I believe the solution was either :turn it off, move head under camera and turn back on again; or reboot. Sorry I don’t remember which was the fix.

After doing that once though, the problem went away, so until the next blip, I don’t mess with it and just turn the machine on normally.

(Used to have a video up showing the problem but it looks like I took it down.)


You are coming up with more than your proper share of new words, you know. I love it! And, back to the main subject, Glowria did this dance yesterday morning, but it had been a long time coming. Just did the ‘maneuver’, turned it back on and all was good. I’m thinking this must happen to just about everyone, at some time.


Does that mean we have to stop when we hit 5? Quitto?


Nope, it’s ditto all the way down. Ditto doesn’t mean twice or second, it indicates repetition for as many ditto marks are used.


Shouldn’t that be “as many ditto marks are used” plus 1? Otherwise seconding would require a pair of ditto marks. Or are ditto marks not the " pair but a single '?

In translating to a word then should Jules have said “Ditto Ditto”? :smile:


Awe, man! You missed the fun…


Yes, I know. I’m a linguistic spoil sport and should just sit on my hands sometimes.:blush:


I’m trying to figure out how to work “whackadoodle” into the conversation.

Just because. :smile:


My basketball coach used to call me “Makadoodle”.


Thanks for posting about this. We don’t expect the grinding to cause damage. The best thing to do to is to continue to turn your unit off and move the head under the camera if you see this issue. I’m so sorry for the inconvenience.