Won't cut all the way through

I’ve had this issue for a while, but didn’t make a big fuss about it because I could sand down when it would happen on the draftboards. Now that I’m cutting on the plywoods, any sandind would be incredibly visible.

I only cut on the proofgrade material and I’ve had this issue with the draftboard, maple, and walnut (all on both the medium and thick sizes). I haven’t tried other proofgrades, but I’m sure it’ll cut just the same. This has happened even right after cleaning the mirrors/glasses on the printhead following the instructions and the laser tube. Here is an attached image of something I just attempted to cut. I took off the protective tape on the top and bottom of the board and still, it didn’t cut through. I’m getting really frustrated because having to try to separate the pieces is resulting in chipping and I’ve ruined quite a few of my pieces and thick plywood boards resulting in monetary loses. Can someone please help?

I have made it a point to hold the material still and check if I could lift the piece out with a piece of tape. If not I always have the option of rerunning the cut.


I had similar issues with my first Glowforge. To mitigate the issue, I started with Proofgrade settings and then switched to manual cuts and reduced the speed by 10. I also used magnets to ensure that materials were flat on the crumb tray.

In my case, the laser performance degraded over time (despite thorough cleaning of all lenses) and my machine needed to be replaced. In your case, I would start by ensuring that materials are level and slowing down the cuts a bit. Support will likely have other suggestions as well.


I’m having the same problem. Very frustrating. I’m usually rushing to cut another piece, and tend to move the plywood before trying the tape-check to make sure it cut. Of course once it’s moved I can’t do much and I’ve ruined several walnut plywood sheets thus far.

Going to try my hardest to remember to use the slower manual cut or test the cut with tape first, just wish I didn’t have to worry about it.

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Does anybody get 100% reliability with PG cuts? It seems all the experienced users slow them down a bit and / or test and run the cut twice. I.e. they don’t expect it to be 100%.

I heave seen people say laser tube output falls over time but I can’t find a graph anywhere. If the lifetime is around 2 years / 10000 hours then some people will be well into that now. Does the GF have anyway to mitigate power loss?

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I’m curious if they are tracking the time on the laser internally (hidden to the user, as we already know they don’t provide us with this information), and use that to adjust the output to the laser to compensate for tube age.

As the tubes also supposedly lose power over time just sitting there and not being used, it might be a difficult task to accurately guess how much oomph the tube has left in it.

That would make it hard to achieve the goal of automagical Proofgrade settings.


I wonder if tubes change electrically as they age. E.g. if you measure both current and voltage do you see a change in impedance? The GF can measure current but is there any feedback path from the PSU to indicate the anode voltage?

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I haven’t had any failures to cut through using PG. Non-Proofgrade is a different story.

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Have had a unit for over a year now. Now that I am anal about keeping the material flat, I never have a failed PG cut. If I get a little sloppy and say, “that’s pretty flat and probably good enough”, then all bets are off.


As a point of reference, I have not had a single proofgrade cut not work the first time. Maybe I’m lucky but between three different machines, two at work and one at home, I’ve had no problems. I sometimes make sure its flat and sometimes not and still no issues on any of the three machines.

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Interesting, are you all in dry areas? Is humidity the problem?

Of course they are, it would be rather silly of them not to track the individual sensors for each hardware device in the Glowforge. The real question is what kind of failure do these laser tubes have? Do they drop of linearly over time or do they just one day go from full voltage to no voltage like a light bulb.

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I’m east coast and the unit and materials are in my unfinished block wall basement. When it rains you can see damp marks on the inside of the block wall. Never wet to the touch, just wicking the moisture. So probably pretty humid.

I’m in Chicago. Mine is inside the house where during the winter its ranges between 20-35% humidity.

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I think they normally fall gradually over time. Googling I find people say this happens but I can’t find a graph. Since the reason is leakage of gas and chemical changes to the gas due to the electrical discharge I think they will normally fail gradually.

They can also fail catastrophically fail if you have an arcing connection to the electrode as that heats it and breaks the seal or if the cooling system fails.

One thing I’ve learned about this company is that it is never safe to assume anything about them.

If you’ve spent as much time climbing through the nether regions of this device as I have, you would no longer be surprised by the things that they “should” be doing, but are not.


I’ve worked for so many software and hardware companies in my time, that nothing surprises me anymore. The only thing that you can “trust” is the code that you can see.

I’m just beginning my journey there. We’ve only had our Glowforge for a few months. My goal is to get a local server running in the near term that I can make prints from.

This project may help you reach your goal, or, at the very least, give you some insight into what goes on behind the scenes.


It would be interesting to see what the true statistics are. When my material is flat and the optics are clean:

  • On my GF PG cuts always cut right through.
  • On my GF PG cuts do not always cut through.

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