I disintegrated my lid glass with a 12 gram magnet!

I received a replacement unit yesterday and I’m up and running again. They said it would be a refurbished unit but it looks untouched so I’m very pleased. Besides sending a link to an incomplete repackaging instructions, Glowforge has been outstanding to work with and very fair. $200 for the repair an $200 for shipping seems more than fair to me. Not to mention they got the replacement unit out within a few days of the notification.

I use social media to promote companies with good customer service and to warn people about companies that aren’t good. Glowforge has been way above par in every aspect of this ordeal and I’m happy to share it.

EDIT: Turns out the problem is probably related to the ceramic magnet and not the Glowforge lid. Check out this video… https://youtu.be/QhlmKHbPFhU

Put tape around your magnets if you use them.

I accidentally dropped a 12 gram magnet from 18" above the lid and it annihilated my glass lid assembly. Just a little word of warning… don’t handle anything hard anywhere near the glass on your printer or you will have 5000 tempered glass beads for souvenirs to remember the occasion



Oh no! So sorry to hear that. Tempered glass is funny stuff; it can be incredibly strong, but just the right impact can ruin your day! Hopefully you can get a replacement lid without too much trouble.


Oh man that sucks. Google “magic rocks” sometime if you want to see how easy it can be to smash tempered glass sometime.

Service already responded via the support forum. That was fast!!

$400 which includes $200 shipping. That is less than I expected.

Thanks Glowforge for not price gouging even though I had no choice except to pay whatever it cost and for responding so quickly.



Repair or refurbed unit. Their option.

Good deal. It’s that cursed shipping that jacks the price. Really reasonable repair or refurb price for lid, camera and alignment.


Point source impact on tempered glass is the worse case scenario. Good advice. I hope they get you up and running quickly!

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Tempered glass is amazing in its strength. I had a sliding door insulated unit I needed to dispose of, so I put down a furniture pad, put the unit on it and folded the pad over it and hit it in the center with a hammer. The hammer bounced. Hit it 3 more times with increasing force. The third time the hammer bounced almost as high as I had swing it from - I was astounded!
After thinking about in disbelief for a minute, I tapped it on the edge and it exploded.
The magnet had to land exactly right/wrong. Probably would have a hard time replicating that unfortunate incident with a 12 gram weight.


My guess is that you are probably right. I’m still going to cover the replacement with an acrylic sheet attached with spots of silicone.


I don’t blame you. After a rude shock like that I wouldn’t take any chances either.

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Glowforge tragedy of epic proportions!!!

So sorry! In the future “May The Forge Be With You”!

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I worked in auto assembly for more than two decades. I have dropped windshields and had them bounce and ring like a bell, and on the other side shatter from the slightest touch when near the edge. Sometimes technology can be amazing. :sunglasses:


Tempered by definition means that the glass was heated to near sagging temps and then quickly cooled. As that outside cooled the glass on the inside gave way but as the inside cooled there was no give from the outside so the inside shrank more than the outside and set up huge forces so when hit with a hammer that is an even force as @PrintToLaser described it does not increase the forces but eases them a bit on the other side. However the slightest crack or deep scratch that unbalances those forces will cause the place adjacent to be unbalanced and give way and so forth so fast it will be like a bomb.

It was not the weight but likely a scratch that caused the break. You could drop a diamond ring on it and get the same effect.


The ceramic magnet is basically the same as hitting tempered glass with broken porcelain or spark plug insulators. It’s harder than the glass and can penetrate the surface on a microscopic scale and that’s all that’s needed to pop it, no high forces required.



I certainly learned something from this. Didn’t realize ceramic could do that. (And I think I’ll stick to the honeycomb pins.)

See above re: Magic rocks :slight_smile: (AKA Ninja rocks)

Badguys use them to break car windows to the point where cops would detain people for carrying them.

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Also popular with cyclists and motorcyclists to catch the attention of idiot drivers not paying attention to the road and causing near misses. Tossing a handful of steel ball bearings underneath a rolling vehicle makes quite a racket too.


And hopefully lands the tosser in jail.