Molten Hot End Heater
I'm a novice 3D printer owner. About a month after finishing assembly of my i3 MK3S+ I'd been through several projects as I was learning how to use the printer, which was working really well. Then during a print the printer stopped with "M112 Called. Emergency Stop" on the display. I started a chat with tech support and they had me restart the printer and start a preheat. After a couple minutes the nozzle fell out of the hot end in a pool of molten metal.
I've been corresponding with tech support on this for the past two weeks and they appear to be stumped. To make things more frustrating they're dragging their feet sending replacement parts.
Any ideas what could have caused this?
RE: Molten Hot End Heater
Uh... Never heard or seen anything like this!
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Molten Hot End Heater
The melting point of aluminum is 660.3* C.
Pretty scary to think the heater could have reached that point, never mind before a shutdown. Assuming that’s what we’re looking at...
Thank your lucky stars this didn’t end way worse. If I were Prusa I’d want that machine back to examine it for root causes and I’d be sending you a factory built replacement and a bunch of other goodies for your troubles. Just sayin’.
Good luck!
RE: Molten Hot End Heater
I'll just leave this here https://themelt.zone/2021/11/05/thingiverse-data-breach-molten-prusa-heaterblock/
RE: Molten Hot End Heater
Seriously? can't imagine that tiny heater cartridge could possibly get that hot or even close.
RE: Molten Hot End Heater
There's no damage at all to the heater wiring, and the plastic parts right next to the heater showed very minimal damage -- just a bit of discoloration and minor indications of surface melting, so there's no way it got anywhere close to 600+C. So it's safe to say the core of this heater is not aluminum. It looks like melted solder so I'm thinking maybe a high tin content. During the preheat cycle when it melted, the displayed temperature was maxing out at 230, which is coincidentally right around the melting point of tin. On the other hand, even the minor damage to the plastic parts seems to indicate the temperature had to be higher than 230, although after cooling the printer and turning it back on, the hot end temperature still pretty accurately displayed room temperature, so the temperature sensor seemed to be working in that temperature range.
RE: Molten Hot End Heater
I think it got too hot!
RE: Molten Hot End Heater
I notified support and will look into the case further and get action taken on it @wreinhold
Shane (AKA FromPrusa)
RE: Molten Hot End Heater
I don't know how this happened, but I'm buying my next printer from Randym9, I love his warranty coverage policies.
😉 👍
Swiss_Cheese
The Filament Whisperer
RE: Molten Hot End Heater
I certainly agree about Randym9's warranty coverage policy. I figured Prusa would tell me to unplug it and don't touch anything, they'd send a new printer and I should pack mine in the packaging from the new one in exactly the configuration in which it failed. When they didn't, I questioned whether they really wanted me to disassemble anything -- disassembling could destroy clues or even the cause of the failure. But they weren't interested.
I've been really disappointed with Prusa's service. They kept passing me from person to person, and with each new person they became less and less familiar with what had happened. They kept changing what they asked me for, between pictures they wanted and what parts to return. They routinely ignored questions I was asking to help me decide if I wanted to return the printer or repair it (this happened well inside the 60 day return window).
I've read a lot about Prusa's spectacular customer support (part of the reason I bought this printer) but I sure didn't experience it. I did receive notification today that they finally shipped replacement parts. I hope I made the right decision not to return it.
RE: Molten Hot End Heater
Sorry to disappoint Mr. Swiss but I’m not an authorized Prusa Distributor...
But I believe my clients in the industries I do serve would tell you that I take their satisfaction with my project deliverables very seriously!
🤨 👍🏻
RE: Molten Hot End Heater
It looks like melted solder so I'm thinking maybe a high tin content
The melting point of tin is 230C so I think I'm safe in saying, no way.
I the block has got up to 600c then it would certainly have destroyed both heater, thermistor and fan duct. Seems more likely that nozzle was only on half a thread and was "blown" of when filament pressure increased.
During the preheat cycle when it melted, the displayed temperature was maxing out at 230,
As the default temp for Prusament PETG is 250 ........
I'm buying my next printer from Randym9, I love his warranty coverage policies.
+1
RE: Molten Hot End Heater
If we accept the weird idea that this heat block was made from a solder alloy (melting temps. ranging from 180 to 220C ), we should assume that somebody at Prusa felt entitled to try a new and smashing joke. Or maybe a competitor brand managed to infiltrate a sabotaging agent in the assembly room, with the purpose to erode Prusa’s reputation. But then, why only one fake heatblock ?. AFAIK no more melting cases have been reported.
Another thing, if the heat from the cartridge distroyed that solder-alloy heat block, first it would melted the metal directly in contact with the cartridge, which would have been left dangling from the wires. We see in the photo that the cartridge is still in place, held by a non molten part of the block.
If you know my opinion, and no offence meant to anybody, this thread started eighteen days late.
RE: Molten Hot End Heater
You may be on to something...
The lack of obvious damage to the wiring and surrounding plastic is suspect.
I’m no photoshop expert but...
RE: Molten Hot End Heater
If we accept the weird idea that this heat block was made from a solder alloy (melting temps. ranging from 180 to 220C ), we should assume that somebody at Prusa felt entitled to try a new and smashing joke. Or maybe a competitor brand managed to infiltrate a sabotaging agent in the assembly room, with the purpose to erode Prusa’s reputation. But then, why only one fake heatblock ?. AFAIK no more melting cases have been reported.
Another thing, if the heat from the cartridge distroyed that solder-alloy heat block, first it would melted the metal directly in contact with the cartridge, which would have been left dangling from the wires. We see in the photo that the cartridge is still in place, held by a non molten part of the block.
If you know my opinion, and no offence meant to anybody, this thread started eighteen days late.
I for one would rather be known as the perpetrator of a clever and elaborate (albeit 18 day late) April Fool's hoax rather than a guy with a few week's 3D printing experience looking for help with what is apparently an exceptionally unlikely failure. But unfortunately I'm the latter (and BTW you'll have to work harder than that to offend me). Does the podcast @neophyl linked add some credibility? The part discussing the molten heater is at about the 30-minute point.
RE: Molten Hot End Heater
Apologies, not looking to offend. I’m the first to say that it’s scary as all get out.
But you have to admit, it is a very unlikely occurrence that will surely evoke skepticism.
I am very curious as to what has happened with your printer. I can’t imagine tin being used in any part of the hot end and I can't imagine the heater reaching the point where it would melt aluminum. Curious minds and all that...
Interested to hear how this plays out. Please keep us posted.
RE: Molten Hot End Heater
The podcast that Neophyl referenced is 6 months old. Hard to believe that Prusa havn't issued a statement.
RE: Molten Hot End Heater
Seriously, no offense taken, I understand the skepticism. My immediate struggle is the decision whether to keep the printer or return it and I'm looking for help, preferably in the form of some sort of explanation leading to confidence this won't happen again. Right now if I keep it I'll be worrying it's going to catch fire anytime I use it.
I don't believe the heater is made of tin, but I also can't imagine it got hot enough to melt aluminum. But maybe it did. If the heater actually has the capability to produce that much heat, then it would require both a failure of the control loop and failure of the fault detection mechanisms in the firmware. As far as I can tell, other than fuses there is no hardware fault protection.
Prusa appears to be focusing on the Einsy board as the cause. They had me take a lot of pictures before sending it back, and I got word from them yesterday that my new printer had "quite an old version" of the board. They won't tell me anything more despite numerous questions. How could an old board (or any board) cause this after the printer had worked fine for the first few weeks and probably 20+ hours of printing?
RE: Molten Hot End Heater
My suspicion is that there is not a single cause, but that multiple things happened/failed. Similar to how a plan crash is rarely ever due to a single cause. Any one failure may have been caught or handled, whereas multiple failures may not be.
And since a computer is involved, don't discount cosmic rays flipping bit. It's rare, but the probability is not zero.
RE: Molten Hot End Heater
I stand by my original post above. It’s clear that some rare combination of failures occurred causing a catastrophic ‘meltdown.’
If I’m Prusa, I want that machine back so I can have my Engineering Team do a thorough failure analysis.
Good luck.