There are a few main reasons why this might happen:
Your optics may need cleaning. This is the simplest scenario, so it’s worth doing a proper cleaning. Check number 17 (17: What maintenance or cleaning does my Glowforge require?) for a link to the official cleaning instructions. Once you’re all clean, test the cut performance to ensure that the issue is resolved.
The material is warped, so the laser beam is out of focus across part of it. Ensure that your material is held flat. Most people use pins to secure their material.
The crumb tray is not properly installed or has debris under the feet, so the laser beam is out of focus across part of it. Check to be sure your crumb tray is seated correctly with no obstruction.
Your material is not consistent across the sheet, so it is more difficult to cut through part of. This applies mostly to non-proofgrade materials: carefully inspect your material, test your cut settings and adjust them if necessary.
Your laser has an alignment problem, so less of the beam hits the window on the laser head as it moves from left to right. Contact support for more assistance.
Your gantry may be off track and one side may be higher than the other. Check your wheels and rails for damage or misalignment. Contact support for more assistance.
Your laser isn’t on a flat — not level which is also good, but flat — surface. This can cause the Glowforge frame to twist. A hint that this could be the issue is if your lid doesn’t close smoothly. Place on a flat surface or shim the glowforge’s feet to straighten the frame.
A couple of other possibilities, at least theoretically:
Your laser isn’t on a flat (I didn’t say “level,” I said “FLAT.” They’re not the same!) surface, so the frame is torqued a little bit (a hint that this could be the issue is if your lid doesn’t close smoothly)
One of your lid hinges is letting go and your lid is out of alignment when it is closed.
90+% of the time If the left cuts and the right doesnt it is crud on the left window under the side that some do not know is there,and most of the rest I have seen are machines that shipping screwed up the alignment. Using magnets or similar fan/air issues can mess up anywhere. I have had the right side go light and even though the window looked good I still cleaned is and saw a slight bit of brown and it worked perfectly after that.
I guess this is the misleading part. In every case where I had cutting issues on the right side of any material, it was because it had been a while since I had cleaned the window on the left side of the gantry, and the left side of the head itself. It doesn’t take much. This is more important than the lens itself for me.
I wish the exhaust fan was on the opposite side, because all the vaporized material is drawn right over this side of the machine. If it was drawn away, it would probably rarely need cleaning.
I leave this here just for historical purposes, but all of my theorizing may not hold up. Read further in the thread to see the replies that changed my opinion.
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To me the misleading part is the idea that dirty optics on the left window can cause diminished laser performance primarily on the right side of the bed. The idea would be that the laser is being scattered and so it doesn’t hit the laserhead correctly. That’s simply not going to happen because the laser light is already collimated when it comes to that window.
It’s possible that there’s some sort of diffraction effect happening, but that seems pretty unlikely because of the way diffraction works. You would need something on the scale of a diffraction grating, and simply won’t give you that. Physics, man.
If anything dirty optics on that window should cause diminished total laser power, which would lead the poor performance across the entire machine, not just on the right.
So, if my theory is correct here then what’s happening is that the overall laser power gets diminished and a pre-existing right to left laser performance gradient transitions from being enough to cut through on the right to not quite enough to cut through. So clean optics would incidentally resolve the problem but not solve the root cause which is probably one of the other items on the list.
Anyway, it’s all theoretical, and just to be safe it’s a good idea to clear your optics because maybe that will solve your problem. Hence it’s in the number one spot and also hence it’s not listed as the most likely root cause.
Oh and also… If having a dirty left laser window would be a root cause for poor performance on the right side of the bed then you would expect one of the first symptoms of needing your optics to be cleaned would be incomplete cuts on the right, and that isn’t the case. Right side cut failure is a fairly rare problem, if that were the primary cause of it then you would expect this to happen a lot more often.
I’m open to countertheories. This sort of thing is difficult to measure and confirm.
That has been the case for me, every single time. I accept my experience may be an anomaly, but that has been my experience.
I use a wide range of materials and the moment I get any cut issues using saved or PG settings, it starts on the right, and a quick wipe of only those two windows has cured it.
That applied in the years I owned my first GF, and also now with the 2nd. It did take some time for me to figure out that was the issue with the first one.
I very rarely clean the lens or mirror. In a year now, I think I’ve only cleaned the lens once (and never the mirror) on this machine. The two windows I mention, however, I wiper frequently. Especially before a job when I don’t want to risk cuts not completing cleanly.
Yes, for me. I can’t think of any time I have cut had issues using proven settings, it didn’t start on the right. Perhaps in the very early days but it’s long been my basic practice to just wipe those windows periodically.
Obviously there are material variables when I used to use weird stuff, there was a brand of ply that was just horrible, but I simply don’t buy that now. I also use cheap store-bought MDF and even picket fence boards for certain things, but I use “overkill” settings to work around expected variances.
Llikewise for me, even when the crud was so light I could not see it. I wiped, it was barely detectable, but solved the issue.
There might well be other issues, but logically the only change from the left to the right side is the distance to the gantry window. Only if the laser is badly aimed or even slightly blurred can that be a cause.
I now keep a wipe in a little airtight baggie so I’m not “wasting” one every time. Those two windows, and the lid camera. Just a simple preventative step I do every week or two. I also use a lint-free paper towel to wipe off the “lid” of the head, which keeps the alignment between power cycles pretty much dead-on.
… and letting the screaming exhaust fan run in addition to my external duct fan, which keeps the whole inside so much cleaner.
They have those little lens wipes for cameras that are a nickel each. I use them on the lenses and then on the lid with added hand sanitizer, first using a paper towel to get the majority.
With only the 4" Vivo fan, it is not enough to succeed anyway, but really helps move the air out with the noisy internal fan. I have come to think that 800CFM would not be too much if it were available. The Blu-Dry just filters the room and both it and the Vivo run 24/7 so even if there was smoke leaking from the GF you would not know.
