My laser cutter will not stop flaming

Hi I’m at my wit’s end with this…
I’ve cleaned my glowforge, try to make sure to focus on the little fan behind the laser, and still this freaking keeps happening.

Not only does it not cut all the way through but a flame starts to pop up as though the fan is not doing its job in keeping it contained.
I have tried taking off the paper and that has worked but then I can’t see anything on the computer when I am cutting. Also I’m using a proofgrade cut and proof grade material from glowforge itself.

Please help especially somebody from glowforge. I’ve had this machine for less than a year and this is making me nuts

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There are two fans on the head assembly. The tiny one on the head itself, and the air assist fan that sticks down on the back of the assembly. That second one doesn’t seem to be working well on your machine, and is the one you need to focus on.


Beat me to it! I was just going to say it looks like your air-assist fan is not functioning properly.

Do you mean this one?

This is literally the one I’ve been focused on during my cleaning… Maybe I’m doing it wrong?
How do you guys clean it?

Yup that is the most likely culprit causing the flame up on the machine. I would suspect it is either dirty or possibly faulty in some way. I’m not sure if there is feedback from that fan or not but it might help support mention the date approximate time of your last problematic print so they can look into the logs. Maybe post some pics of your fan and gantry plate as well. I have only cleaned my air assist fan once in the year and a bit I have owned it. When I did wiped it down with water and then alcohol.

Do you take the backing off or just somehow clean from the front?

Sorry I guess it’s not as clean as I thought it was… This is the first time I took the belt off and I’m really nervous about putting it back on

Wow… the wheels on that carriage plate look pretty dirty as well. You might want to give the machine a pretty thorough (but careful) cleaning.

Its not that big of a deal, I made a video on how to get it to roll back on. I disassembled and disconnected the fan to make it easier to clean, but can’t recommended doing that unless the support staff tell you. Good first step tho is to blow it out with compressed air or something like that then go in with cotton swabs and gently and thoroughly clean all the blades.

Video re seating the belt.

Also here are the instructions for cleaning the fan off the support page.


I left mine on the plate, but (outside of the machine) drenched it with isopropyl alcohol and scrubbed it out with Q-tips and an old toothbrush, then left it to dry.

The next time I started up the machine, the fan was frozen – I guess some of the dissolved goop had collected in the spindle and dried. Once I broke it loose, it worked just fine. :slight_smile:


I’m sorry you’ve run into some troubles printing.

Could you follow these instructions to clean your air assist fan and let me know if the prints improve?

They have thank you!

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Could you have inadvertently place the fan on backwards after cleaning? I did this once and realized it after getting flame ups when cutting acrylic.

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The fan is installed the same as the one shown in the pics on the page for cleaning it.

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I had a lot of problems with that fan and discovered that magnets I was using had their fields interfering with the fan and causing the fan to fill up with crud.

With the Glowforge off I got the shopvac+c-pap hose to cover the exit shroud of the fan. By running the vacuum pulling air through, if the fan is not jammed it will spin up. then I poured Purell through the fan washing away all the crud into the vacuum. Then by letting the vacuum run another half hour or so it would dry completely

This cleaned the fan very effectively, and without removing the carriage.

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!