As horrible is that image is- I am glad that did not take out the house. Fires, in general, is my biggest fear. Well before the Glowforge, we added mesh enabled fire/CO2 detectors. When we got the PRU, I’ve added a flame detector pointing down at it. House > Glowforge.
<-Activating CSI:Miami mode.->
Looking at the image, That’s for sure a fire that started on the left side of the machine. I bet the machine was sit cutting while the fire was going. Pretty sure the fan on the bottom of the head assembly accelerated the flames. It also looks like the fire got hot enough to melt the reservoir and the hoses for the coolant lines. Once the glass got hot enough it stress cracked. The tough part is what order all of that happen. I may or may not know that cutting cardboard at Gundam power levels starts fires pretty quickly.
<-Deactivating CSI:Miami mode.->
I hope the user is going to be okay. And the damage to the room is minimal.
You can tell this was burning for a while. The fan was pushing flame out the slot on the front, and heat circulating around the left side to the exhaust long enough to melt the entire airflow path and front panel. The “explosion” was more than likely the tempered glass blowing up once it hit temperature. Tempered glass is under a lot of pressure and doesnt fail gracefully.
I’m not sure why he wanted to post this on social media like it was the fault of the glowforge. This is almost definitely user error. He never should have left it alone
I don’t know how you would do a four hour cut that would not kick back as too complicated unless it involved a lot of engraving. I have had to make changes to get it to go at all and the longest ever was three and a half hours. I have seen smoke ignite long enough to scorch the work when the head fan was now working well enough and seen the end of a long narrow engrave turn to charcoal when the head fan was working and blowing like a torch in that one area. I have not tried to cut things like cardboard or foam core but have been surprised how hard it has been to have sustained burning.
I would agree that the glass breaking would seem like an explosion, but to get the smoke and fumes to be at the magical percentages to ignite explosively would seem unlikely, as would the smell of what was being cut, even if the exhaust was less than optimal.
To stand over a four hour engrave and do nothing else might be a lot to expect, and I cannot believe the Glowforge was not making very strange sounds before things got that bad. I cannot hear well enough to make out what folk are saying a lot of the time, but I can tell what the Glowforge is doing from the sounds it is making even from the next room and will usually look in on it at least every half hour or so if it is behaving itself.
For the fire to get that far along, and obviously melt that corner more than the rest you do not have to have been there to understand a lot of what happened, any more than you need to be there to see that the glass is broken.
As for carbon monoxide it think it unlikely to have been a serious build up enough to need a hospital. Other chemicals from the work or burning Glowforge is another matter.
I think a lot of people would love to know more but I’d be surprised if we learn more through Glowforge. They’ve always been pretty tight lipped about any information that can be tied to any particular person.
Maybe the original party will give more information at some point.
I feel for him, of course, and it really drives the “don’t leave your laser unattended” advice that they give. While I suppose it might have been the machine itself catching fire, I am much more in the “flammable materials burned in there for a while” camp.
(gallows humor follows)
Also, are we in the wrong category? Is a mixed media sculpture of metal plastic and shattered safety glass technically “made on a glowforge”?
I wonder what the Glowforge “log” looks like at their end for this operation? As stated in earlier comments - it seems like it was a fire that started (which certainly can with a laser) that went unchecked… My guess is a LOAD error “Laser Operator Attention Deficiency”.
I am pretty strict about things like this but even with me it depends on what I am turning into vapor.
I am usually within ear shot of bOb. I also look at it from time to time when in the shop with it.
Some things that will definitely burn (paper cardboard balsa etc) get an undivided attention session.
Other things like historically safe woods (at known speed/power etc) and acrylics, are a little more relaxed attention wise. Also, for items that will be done in minutes, it makes no sense for me to wander back to my desk (about 40 foot away) since I will be popping it out so soon.
With long sessions I find something to do in the shop. As much for burn hazard as the gantry going askew and other calamities that would require a fast lid lift.
If you are in the room when it goes south, you will know it.
Based on the amount of soot, the high temperatures, and the long intense burn, Im pretty sure it was some sort of plastic that caught on fire. Either acrylic or maybe something like HDPE or polycarbonate that resembles acrylic but doesnt handle lasers so well.
Yeah, it was cooking for a while. And as previously stated, the logs are time-stamped. GF knows exactly how long it took for someone to notice, and probably have a good idea of the material that was fed to the machine.
There you go @dan, documented experiment on just how long it takes for a glowforge to burn down. Nice to know.
Good evidence of containment too, for those who questioned the wisdom of a laser with a plastic case.
Earlier in the thread, I mentioned an Illustrated parts breakdown. The team builds a great machine, but there will eventually come a point when we will need access to more than lenses and windows.
I just presume that any part would be available to us by contacting support…
The “explosion” was the tempered glass. It is resistant only to 450 degrees F but it could have popped even before that point as it tried to expand against the aluminum that frames it.
Whatever burned, probably was not acrylic. Even though acrylic will readily and very easily ignite and quickly spread, it produces no heavy soot. 90% of its mass turns to gas. Photo coming for reference. (What can I say, I’m a fire bug).
Hey, not to piddle on anyone’s story, but the guy said he came into the room to discover that the machine had “exploded”. (His word.) He did not say he heard an explosion or that he was even aware of anything going on. (And apparently he was completely unaware for a long time.)
I suspect the material caught fire, he wasn’t there to do anything about it, and the fire melted the machine. That’s sure as heck what it looks like from that picture.
The case is slumped and melted, not blown out. The glass fell down into the machine, it did not go spraying outside of a very confined area. There’s very little debris on even the lamp right next to the machine…just a few speckles. I don’t see any type of fire extinguisher residue, so I also suspect the fire just burned itself out when it ran out of flammable material inside the case. It did it’s job. The scorching is limited to the machine. It didn’t even singe the safety glasses on the table.
Even very small uncontrolled fires throw a heck of a lot more smoke than that did, and you’ll have to scrub walls and replace sheet rock. That thing didn’t explode, it’s just his “interpretation” of what happened.
And if he is taking the time to take photos and tweet before going to the hospital for the “carbon monoxide” treatment, I’m not particularly worried about his health either. I suspect that statement was also for effect. (I do hope he didn’t inhale a lot of smoke though, depending on what he was burning in there, there’s some toxicity risk. I’ll bet he did give himself one hell of a headache when he entered the room.)
None of that is going to matter to detractors though, and that’s the really unfortunate aspect of this.
(I keep forgetting the point I was going to make thanks to Mike, who’s PMing me…cut that out!)
I’m definitely impressed at how controlled the situation is. There’s almost no soot on any of the surrounding areas.
I think some people won’t buy based on this, but those people probably shouldn’t have a laser to begin with. If you don’t know that this is a danger with the equipment (regardless of brand), you really shouldn’t be messing with one.
(I am posting this for absolutely no reason other than I haven’t posted a finger picture in a long time and it’s about due. Edited to add: that’s not a booger on my finger either, it’s mpipes head )
Edited to add: that’s not a booger on my finger either, it’s mpipes head 
)