What the heck is this!? Happened about 1 hour into a print (the very end), picture included


What the heck is this? It ruined a bunch of work at the very end. Started getting all crazy and printing like that.

Is something broke :frowning:

Had the same thing happen to me. I was enjoying the high speed setting on my Pro. If it wasn’t the speed, (something probably well over 1,000), it could also be a loose belt. Specifically the belt under the gantry that slews the head left and right (the x-axis or “driver” belt). If the belt seems loose, read @Jules 28 Aug post here. Hope that helps!


Clearly the laser is firing fine and it’s a problem with movement in one direction. Like alan_ferrell said, check the belt. Also check for obstructions. Was it making any strange noises? Could it have been hitting something? Did you have something on the bed to hold down the board?

In all the time on the forum, I’m not sure I’ve ever seen an actual motor failure, so it seems unlikely that your machine is serious broke.


Disney C&D mid print. :rofl:


Appreciate the help, I took a look at the leading belt as described in the link, and it is pretty tight (I’ve had the Glowforge a few days, so its barely done any work. A few prints. If I move it manually from left to right it moves silky smooth. But when the Glowforge tries and move it sideways, it “chops” along.

It also produces an error, “Bumped : The laser head experienced a bump. Open the lid and check for anything in the way before printing.”

Here is a video of it bumping along. https://youtu.be/VaDzmRAsqdQ

It might just be the recording, but that sounds super rough compared to mine.

With the power off, can you gently move the head side to side? It should slide almost silently and smoothly.

When I manually move it, it seems ok but I don’t know what to compare it with. I mean it isn’t smooth like glass on glass, I can kinda feel the “grooves” in the belt when I manually slide it around, but it moves with maybe about 10% resistance. Here is a video of me manually moving the different axis

That looks normal.

What speed was that engrave running?

Whatever standard settings with proofgrade medium draft board. But mind you, the original post above was before I realized something was wrong. So the first time I noticed it, was that print messing up. However I can’t print now, it gives me the error mentioned a couple posts up, and the “vibrating / choppy” movement on the left to right axis happens after I turn it on, or when trying to print. It doesn’t get that far. It starts skipping then gives an error about the laser experiencing a bump and checking for anything blocking its movement.

The machine has no way of detecting head movement - there are no sensors to confirm that the stepper motors are doing what they are told to. This is not uncommon in consumer products with motion control, like CNC machines and of course, the GF.

What I suspect has happened is that the motor itself has failed, and that the control circuit is sensing current overload when sending signals to the motor. That’s the only “feedback” the machine has.

You could try removing the carriage plate (instructions are in the support section, here) and checking the rollers, and also carefully examining the drive belt, especially noting its path when you remove it from its drive motor and opposite pulley. Take pics of everything, as support will likely ask for them.

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Holy E Crap. That is a lot more than I’m wanting to tackle without hearing from a support person, I guess :frowning: I do appreciate your help and perhaps they will have me do the same, but I’d be nervous I’d make something worse.

This is a brand new unit. I wonder if these are common issues or if I’m simply unlucky lol

Not common at all. It’s always been a belt tension issue, at least, that’s all I remember seeing for engraves skipping like that. I’ve never seen it generate the error you’re seeing, however.

Do I email support? Or does this post suffice?

This post counts as opening a ticket, so no email required. If you emailed it would just slow things down because then that’s two tickets. Good luck! It could take a day or two for a support person to reply but they WILL get to you C:

Ok, I’ll keep checking. Sucks to get a new Christmas present and not be able to use it :frowning:

Where art though my support :frowning:

It’s a holiday today - so I assume they are off work.

I see staff posts in this forum today. So someone is working :wink:

Just sucks a family of people over not able to use the main Christmas present.

Well, your issue is most likely hardware related so I’m not sure they can quick fix anything.

I’m so sorry to hear that you’re running into trouble!

I appreciate you taking the time to include the individual videos you outlined, and for checking the tension of your belts. I’d like to take a look at the belt located underneath the laser arm. Would it be possible to take a picture similar to this:

Also, has this trouble appeared in other prints, or just this particular print?

Once we can review the image, we’ll send over the next best steps.