Yellow window has a burnt spot on it

Hello, I just received my glowforge on Wednesday and did a few cuts. When I went to do a cut on Friday it was all over the place with the laser printer head going crazy and trying to go off the side when it can’t. I took it apart to clean the lense on the bottom but notice that the yellow window on the side has a burnt part on it.
What can I do for this?

Trying to go past its limits could just be from the head getting bumped or moved while the machine is on – make sure you never move it manually without turning it off first.

The damage to the window looks like the laser beam went out of line for some reason. Had you cleaned the optics prior to this? Could the mirror be seated wrong in the top of the head? I’d check that before doing any more cuts.

If nothing is out of line, I’d contact support before trying any more cuts. If you find the mirror was crooked, you could re-seat it and try another (small) cut to see if the problem is fixed. Either way you’ll need a replacement window, but if things are still wonky you shouldn’t use it until support can troubleshoot, since you don’t want to risk further damage to the head.

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Actually I don’t think a crooked mirror would cause this, since the mirror is after this window in the laser path. I think your safest bet is to just shut it down and contact support.


I foresee a warranty replacement in your future :frowning:


It looks to me like the laser head wasn’t seated properly when the machine fired up. It has to sit firmly down on the magnets.


Seeing that the burn is at the bottom I would agree with this as it is far more usual for misalignment to mark it side to side and primarily when the head is at the far right but working when the head was near the left. The burn is at a single point that indicates it did not burn differently from left to right. As it is at the extreme bottom, the area it normally fires through looks fine though it needs cleaning.

Replacing that lens may be tricky as one of the fasteners looks to be where the laser hit.

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You don’t replace the glass, but the metal ring the glass is seated on. It should unscrew from the print head with no trouble.

Maybe not so fast as that is where the laser hit? I can’t see really well but if the area of the red arrow is melted that could be a problem, the green arrow area is definitely melted.

This window definitely needs cleaning but shows the area of greatest laser power going through that window (purple arrow) which is well away from the damage in the other image where the orange arrow is what it is supposed to be like…

A Glowforge can’t cut metal. The threads on the back of this metal ring are going to be untouched.

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That’s not melted. It’s one of the little indents where they glue the lens in.


Thank you everyone for your tips, I have tried them all and it still isn’t working and still waiting for customer service to contact me. Have this nice machine and can’t do anything on it now.

How long does it usually take for them to contact you back? Does anyone know, because it has been since Friday when I first contacted them.
Thank you.

As they will not be available on weekends and have a backup on Monday I would guess it will be by Wednesday but it is hard to predict.

I don’t think they officially work on weekends, but there are some overachievers who still respond at times, so don’t give up hope. :wink:


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