Entire laser head horizontal arm is 'bucking' or skipping

I spent over an hour cleaning the machine. Trying to fix this.

The laser head is either getting stuck or skipping. but I THINK it’s just going too fast for it’s own good. The settings are at full power and 485 speed, but it’s like when the small details get too fine, it is tripping over itself. Then my 3 passes aren’t aligned and my product is ruined.

It’s almost like the left and right motors moving the arm up and down aren’t timed right. Causing binding when the arm gets tweaked a bit.

Vertical belts are not loose. Horizontal one isn’t tight but doesn’t seem overly loose. No teeth in any belt show wear or damage. With the machine powered off, I can freely move the arm and head all around. However, I can easily tweak/twist the head/horizontal arm to NOT be aligned, meaning the left and right sides can be a few teeth (on the gears) off. It realigns if I release it, but shouldn’t it NOT allow itself to do that so easily?

Is it possible my design is too detailed and the speed setting is too high? I only really notice this on higher detailed designs. I haven’t had any error messages, so not sure if that means it’s more a mechanical issue than an electronic one. When it skips or bumps itself, you can see the whole machine move a tiny bit. SOMETIMES it skips but doesn’t get misaligned, other times, it skips and then it is off. It seems to be the left belt/area as the culprit.

What are you cutting at 485 speed? (That’s pretty fast…are you working on paper or something really thin?)

Slowing it down a little might help. You’ll also want to drop the power if you do.

Might want to just run a test cut or two at slower speed on something that you can cut quickly to see how much to drop the power. (just a little rectangle or something.)

If everything checks out systems wise, you might just be going at it too aggressively. If it’s that intricate, it will never get up to that speed anyways. A speed setting of 285 will be half of 485; I’d try that and 50 power.

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cutting magnetic sheeting… and I just tightened the tension on the left and right belts using that rear wheel, pushing it rearward a hair and retightening the screw. Seems like that MAYBE helped 20% or so. But there’s still a thud or clunking sound on forward and backward movements. I dont want to bandaid fix it by dropping the speed and power. I might have to since I have orders to fulfill but this is something that is recent. Almost around the time GF upgraded the speed and power settings. I had to reconfigure some stuff.

SO is it possible that nothing is wrong with the machine but my settings are just out of it’s abilities?

Didn’t know we could cut magnetic sheeting with this.

The magnet might actually be pulling on the head and causing it to bobble at the higher speed with a sudden stop…you might want to watch one of the prints very closely, and see if you see movement on the head when it comes to a sudden stop or change of direction.

Or maybe support will have an idea for you to try.


Try a different material with same settings. If it works fine, then it’s the material your using.
If it still has the issue, the try slower speed with higher power. If it’s still and issue, then it’s the machine itself and not material or settings.
Process of elimination.


Might also want to check the tension on the belt underneath the laser arm…might as well check all 3 while you’re at it.

Yeah it’s not the material. Tried oil board for a stencil and same problem. Lower speeds still have that bucking or clunking sound and are bumping the machine enough that I can feel it. Are the two wheels on the right rails supposed to be loose? If I pick up the arm a millimeter, I can wiggle the wheels left and right about an 1/8”. Both. Left side is tight.

If anyone can open their GF and wiggle the whole arm/tube/head thing just a little bit, like you’re moving bicycle handle bars, I’d like to know if yours is loose too.

No. Mine has no play in it whatsoever, before the belts themselves move on the motors/idler.

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That’s what I was afraid of. The entire arm seems loose to me. Like bicycle handle bars that I can turn right or left just a little bit. Doesn’t take much pressure.

Maybe that is causing the whole thing to bind a little bit at a time and the whole arm twists.

When it happens, my design gets cut but with a new angle, like the image has rotated clockwise a couple degrees each time. With three passes, it’s ruined.

In my opinion, it has to be mechanical.

I have done some really intricate cuts at full speed (on paper), the machine keeps up with it just fine.

Each moving part has a plate that the wheels mount on (one on each side for the gantry, and the carriage plate for the head). Grab them securely and see if you can get any play in the belts that they are attached to. Also try moving the gantry in relation to each side plate - hold each one securely against the side rail, and try wiggling the gantry to see if there’s any play there.

I get the most play in the whole arm, it can move like bicycle handlebars turning left/right. Not much, but seems wrong. Pulleys have been removed and tightened. Belts seem fine tension wise. The two top track wheels on the right of the arm can move side to side on their bolt. Shouldn’t they be tight but free spinning?

Yes. There should be no play in any of the wheels or between them and plates they attach to, or the gantry.

Oh no! I’m so sorry you’ve hit a snag. Would it be possible to get some photos of the prints experiencing bucking or skipping you’ve described?

Additionally, I’d like you to perform a standardized print for us to review. Seeing the print results will allow us to suggest the best next steps. At your earliest convenience, please perform the following:

  • 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.

  • Send us a photo of the finished print

hey Jeremyh,
thanks! But I think I’ve figured out the issue. I know troubleshooting always starts at step one, but I’m beyond that and in a hurry. Can you tell me if the small plastic wheels attached to the arm and that run on the top of the side rails should have any play in them? The screws that hold them in are tight BUT the wheels can move in and out on the bolt/shaft that they spin on. Are there bearings in there that could go bad?

Interesting…I started having the exact same problem yesterday. Could be coincidence, but then again if the left and right belts are controlled independently, it could be software.

Myself, I was blaming the belts, but I will try to check their tension.


Check my previous post. Same problem you have???

Hi @TypicalAdamo! Thank you for the reply. My apologies about the delay in getting back to you. Typically the wheels on the laser arm are not a source of trouble unless one is cracked or visibly damaged. Based on your description, that seems unlikely to be the source of the issue here. I’ll need some more information before I can advise about the next steps.

Could you please tell me more about the trouble you’ve been experiencing? If possible, please post a short video of what you are seeing.

Could you please also let me know, have you had any prints that didn’t turn out as expected?

So can anyone with a working GF tell me if their laser head arm can wiggle on the tracks? Meaning, can the left side or right side move independently up or down the track even just a little?

I believe this might be my problem. My laser head arm has too much play, like a bicycle handlebar that turns right and left just a little bit.