Proofgrade cut failed after engrave

Full sheet of proof grade thick acrylic failed. Cut a bunch of panels fine then failed on this. Only dif was this had an engrave pass prior to the cut. Running it again with 2 pass cut this time.


Ouch. That’s not fun. Somewhere along the line I think @takitus noted some issues with cuts that didn’t go through after a long engrave, but that was with his pre-release.

Were the cuts that didn’t go through the final cuts, as the last thing before the print was done?

Wonder if this is a heat issue.

Could this be the result of slight variations in the thickness?

It failed the cut pretty badly. Other than the center right portion it only penetrated the board about 2mm. I busted out the center panel with a screwdriver and it wasn’t even close to going all the way through. Strange thing was that it cut another panel perfectly just minutes before. I’m wondering if heat in the tube from the engraving had something to do with it. I cut all the other panels we needed manual with 2 passes just to make sure we’d have enough material to get it all done.


Quite likely the tube heating up. They used to do cuts before engraves to work around that problem.

Have you got a pro or a basic?

How warm is the room?

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The earlier issues were described by Glowforge as an issue with a batch of defective tubes. Claimed that was fixed long ago. Would have to do a controlled test to see if it was repeatable.


So I tried cutting some thick proofgrade acrylic last night using proofgrade settings and it just caught fire. Poor penetration. Every thing else cuts fine.

You should post this as a new “Problems and Support” topic, since GF staff will generally only address the original post in a topic.


Oh no! I’m so sorry that happened. If you know, please provide the date and time of the print this happened during. If you have any photos, please include them as well.

or not.


Sunday Nov 19 around 9 or 10pm pst I think. Ran it twice and had to abort shortly after I started each cut due to fire. Third time I switched to manual cut and did 2 pass at 170 speed full power, checked it and ran a third pass to get through. I cut some thick acrylic today at 150 speed full power and that got through in 2 passes with no fire. Lost 1 and 1/4 sheets of the thick proofgrade because it either didn’t cut or caught fire. I was able to salvage most of the second sheet. I’ll post a picture of the burned cut asap.

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So, does Glowforge refund the cost of ruined Proofgrade, or replace the material, or give a store credit when this sort of thing happens?


I’m guessing that would depend on the investigation. Nothing to do with this topic, just a general observation… Most of the problem reports I have seen, folks are adamant that the problem is with the machine, or automatic settings or material. Might be. But I usually roll my eyes when someone claims the problem is definitely not the operator.

And yeah, usually when I say something like that folks start getting defensive and double down.


When problems arise, look to the last human who touched it :wink:

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Sure, but every cut I’ve done on clear proofgrade acrylic with default settings in the last 3-4 days has failed or caught fire. The earlier thick sheets cut fine and no other materials have failed or had problems. It’s been a delight to use the proofgrade material and I’ve adjusted the thick acrylic settings to work, I’m just bit bugged to lose a full sheet and I don’t want myself or someone else to burn down the house.

That’s a Support issue for sure. Wonder if they got something mislabeled in PG land? Perhaps it’s a bad batch of acrylic too. Did you check the material thickness with calipers and then check what the GFUI used for the settings? It may be thinking it’s some thick stuff that needs double the power.

And again, “Nothing to do with this topic” or your post. More responding to Ian’s post about whether the PG would be replaced. Probably a hundred posts about the machine or S/W ruining precious PG. Not going to estimate the percentage of those P&S topics where further investigation turned out to be operator errors. But sure seems to be very, very high. Still, Support will have to decide whether replacement without cause is a better option than determining whether the company was responsible.

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Thanks for the details. I apologize for our slow reply. Unfortunately, after research, I’m going to recommend that we replace your unit. I’ll email you in a moment.

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