Square corners not square!

We’ve had our GF for about a week and a half, and as we’ve been experimenting with designs and materials, we have discovered that it doesn’t cut square corners. I tried to make a simple box last week and couldn’t assemble it correctly because the corners weren’t square. I chalked that up to my own error, but I was going to do double-sided engraving on a piece this morning but I can’t flip it over because the outer square that I cut isn’t actually square.

To test it I drew a perfect 3.5 inch square in Illustrator and uploaded it as an SVG. Below is the shape that got cut. If it were perfectly square you could flip it over or turn it 90º and it would still fit in the hole, but it isn’t, so it doesn’t. As near as I can measure using my digital protractor, the corners are, clockwise from the top left, 88.35º, 91.05º, 89.25º and 90.55º. I can flip it from top to bottom in the hole, but not from left to right.

I thought maybe somehow it had something to do with the camera fisheye problem, but I get the same results whether I cut the shape off to the side or right in the center of a piece of proofgrade draftboard. I get the same problem in proofgrade acrylic. And the non-square box I couldn’t assemble was cut from proofgrade plywood.

Below are some photos. Any ideas?



I believe someone else had that problem recently as well. It required a replacement.

Your square should be square regardless of where you place it - it may end up slightly offer to one side or another as a whole object depending on where you place it but it should cut dead square. I’d suspect the gantries aren’t square or staying square.


Did you check to make sure the tray is seated properly in the dimples? Is the gantry seated properly on the tracks and perpendicular?

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The crumb tray and printer head are properly seated. I don’t know what to tell you about the gantries.

I noticed the same behavior with mine. I took a machinist square and with the Glowforge powered off very carefully adjusted one side of the gantry to square it to the side rails. It has been working well so far, but I have noticed that it does not cut perfectly square all the time.
I am working with support on another similar problem though so mine may not be a good example of what should be happening.

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Thank you very much for that. I am not going to attempt to adjust the gantries until I get very specific instructions from tech support, since I don’t want to violate the “don’t attempt to service it yourself” warning in the manual.


I wonder if there is another issue with the alignment procedures after boot. After it locates the head, it moves the head assembly to the far left and takes images of the drag chain cover (the black powder coated metal cover over that’s over the flex connector) and adjusts the Y1 and Y2 steppers. Then homes out to the upper left.

This is one of those things where lid camera alignment (pitch and yaw) and how well the lid seated can affect those types of calibrations.

Hopefully, support/engineering can solve this soon.


I have observed that a regular array of 36 squares engraved with slightly skewed motor coordinates but the lines themselves were still perfectly horizontal and vertical. I.e. not a faithful representation of the design file under a translate / rotate / scale transform. In fact, not an affine transformation of the SVG file.

Just adding a reply to keep this thread alive in the hope that someone from tech support will see it and give me some tech support. I’m sure you’re all very busy and I don’t mean to be too impatient, but my colleagues keep asking me for updates so I need to have something to tell them.

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Might be worth tagging someone from support. I had to tag dan and rita twice before I got a response on my topic.

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4th day, so I expect you will hear from support soon - @Rita? I know they are very busy, and I’m sure they appreciate your patience.
Your post prompted me to check mine, it’s good.

Just noticed mine doing the same thing. Tried to flip over a rectangular cut piece and it wouldn’t go in the hole once flipped. Took it to a square and 2 angles are over 90 and 2 are just under. Harrumph.

I’m sorry for the late reply, @leman. Thank you for letting us know about this. There are a few troubleshooting steps I’d like you to try.

Could you please do the following?

  1. Turn off your Glowforge (this is important to avoid damage to your unit)

  2. Open the lid

  3. Using both hands, gently roll the laser arm to the center of the bed, and then back and forth about 3 inches in each direction.

  4. Check the rails for any dirt or obstructions

  5. Continuing to use both hands, gently move the laser arm to underneath the lid camera

  6. Gently move the head under the lid camera

  7. Turn your Glowforge back on

  8. Print the Founder’s Ruler on the piece of Draftboard we included in your Proofgrade shipment for troubleshooting and record a video of the print

  9. Let me know the date and time of the print. The video can be sent to support@glowforge.com

Thank you in advance!

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Hi Vee. Thanks so much for getting back to me.

I performed the steps you outlined and the resulting video is now uploading to you. The results were encouraging!


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Thanks for taking the time to do that. Based on the video, it looks like you should have luck with your square designs now. Could you please try printing one and letting me know how things work out?

Thanks once again!

Good morning, Vee.

I just printed the same test square that I originally posted about (at about 9:43 am PST). The results are marginally better: I could force fit the piece into the hole when turning it 90 degrees or flipping it over, but it sill isn’t perfectly square.

Did you do something from your side to make any kind of adjustment to our machine? Or was it simply the act of rolling the laser arm back and forth a few times that led to the success of the founder’s ruler experiment?


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Hi again, Vee.

Just as a follow-up, I just tried printing a file at about 12:05pm PST that included a 6.75 inch square and it did not cut square. I cannot fit the piece into the hole when I turn it 90 degrees or flip it over. It seems to be about as off as the piece I first posted about.


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Thanks so much for printing those tests and providing that information.

Unfortunately, your unit has a problem we can’t fix remotely. I recommend we replace the unit and will be in touch via email to sort out the details.

I’m so sorry for the bad news.