Inaccurate Cuts

I’m cutting simple vector shapes for a box/tray. For some reason, there are inaccuracies that I can’t explain. Sometimes the cuts overlap a nearby shape or a hole in cutting within a shape is off-center so nothing lines up when it comes time to assemble the box.

Is there a way I can fix this? My files are clean… there’s just no explanation as to why the laser sometimes has terrible accuracy.

Cutting on PG Draftboard and Medium maple ply.

You may want to upload the file so that we can take a look at it. It could be something simple along the path to you may have two overlapping paths. I have had that issue before. Also, what design program are you using.

Can you post a copy of the file? My first thought is you need to Unite or Merge in Illustrator.

I typically just copy/paste straight out of Illustrator, but here’s an example.sample

See the top left shape? The two small holes in the bottom left of it? This is how it was cut…

They’re off by a good 1/8”. I finally got it to cut right, but it was my third try and with minimal shapes on the cutting area.

It seems the more I have it cut, the less accurate it becomes. But it’s unacceptable to do a dozen small cuts… and it used to work fine where I could cut an entire sheet FILLED with shapes and have no problems.

I’ll also add that sometimes it doesn’t even complete the cut!

Is this because I copy/paste rather than upload an SVG/EPS? I don’t think it is… mainly because my Cthulhu Dice Tower is an SVG I have uploaded, but these inaccuracies made me burn through SEVERAL sheets of Maple Ply before it got it right. Had to save money ($16/sheet) by Frankensteining scraps to get all the small pieces done. ಠ_ಠ

Before you upload the file do you group(Inkscape)/merge them?

Well in Illustrator, I don’t group them, but I make sure they’re all boolean merged/subtracted correctly so they’re clean vector paths.

It might very well be something with the Copy/Paste workflow you’re using. Mine come across 100% accurate, but I save them as SVG first. (Truth in advertising, that is mainly because my older version of AI doesn’t have the copy/paste ability, so I can’t use it, but they still come across accurately every time.)

I would try using SVGs to bring them across, because that’s the only thing I can think of that might cause those holes to shift. Vectors saved as SVG are treated as a Group for moving purposes in the GFUI if they are enclosed in a closed shape…I’m not sure the rule is the same for copying directly into the interface though. They might have shifted when you moved the shapes around for placement.

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I’ll give it a shot with the next batch, but I don’t believe that’s the issue. My Cthulhu Dice towers file is an SVG and I had the same problem…

Well, you might want to check the file too…if it’s just happening on one, it’s likely the file.

But that’s just it, nothing’s wrong with the file… When the problem occurs, I scrap the parts that messed up, remove the good ones, throw in some salvaged scrapwood onto the bed, reposition the parts that didn’t cut right in the GUI and cut. Then they work. Most of the time. The more shapes I take out, the less likely it is for screw ups to happen. =P


@Jules I took the file as you did and saved it as a plain SVG, grouped the file in Inkscape and it came out accurate.

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Don’t know what it is yet, these are just ideas to try to track it down. :slightly_smiling_face:

Yeah, I had it and only 2 other shapes… and it cut fine. Same shape that’s been screwing up when with a whole mess of others. =P

Make sure you never manually move or bump the head while the Glowforge is turned on. To me it looks like it got bumped at some point. Is there a chance the air assist below the head is bumping something within the bed? Like a magnet or something?

Ever since my Glowforge has no problem with booting up, I’ve not touched the head (when on it off). No magnets being used for these cuts either since the sheet of draft board lays flat. But even then, how would I fix that? I originally thought it was a calibration issue, but it calibrates every time I turn it on, heh.

Even if the draftboard is flat (or maybe especially) I think it’s worth holding down with pegs or magnets. I use those to hold down pretty much everything, unless there’s not enough room on the crumb tray. At best, it will work, at worst it will remove one more possibility.

Well even so, the wood lays flat and it’s clear that’s not the issue as it pertains to these inaccurate cuts. =(

Is it possibly location/bed area induced? Is it ghd same part/area of try he bed that always/most often messes up? Don’t know why that would happen but maybe?


Hmmm, nothing I’ve noticed. The overlap has happened in the middle and the left… the altogether shifting has also happened middle/right and far left/top. Nothing really pointing to any kind of pattern…