Printer Head bottom cover started melting

I started a print late last night that was going to take about 8 hours to complete and woke up to a filament mess. I cleaned the mess thinking it was just a failed print and found this had happened.

My guess is that at some point last night the head may have pressed down on the filament or dragged it and then pressed down. Now there is a ton of filament inside with part of the plastic bubbling up from the head melting. I ended up with a bunch of this as my print model.

Was supposed to be this…

(Flux 0.2.11 x64 w/ fw b15)

Is that filament oozing out from the inside of the printing module?

If so, you’ve probably got nozzle that’s not 100% tight in the heater block, or a heater block that’s not 100% tight on the heat-break/heat-sink above it…

Curious to hear what FLUX has to say and if you get “authorization” to take it apart and investigate.


That is an interesting scenario that could have happened, would look like to see what the Flux team finds as well. My tinkering side wants to open it badly to see what may have happened, but will wait on what the Flux team will want me to do next.

1 Like

I was worried about something like this happening. If it was indeed a leak from inside the head, then I did not expect that. But if it was just a fail that led to hotted goop, then it worried me that the whole bottom was shrouded like it is. It pretty much HAS to be disassembled now, but I too wonder how the Flux guys expect us to resolve this. I don’t blame you for wanting to rip into it. I’m tempted just to learn more about it, but I don’t want to do anything to screw up any warranty claims either. I’ll certainly be keeping an eye on this for a response.

Hey @simon any updates on my request? I sent it a couple of days ago, wasn’t sure if you guys hashed out a plan to check this issue out or have seen the request yet. I know you guys are fielding a ton of inquiries, but wanted to find out if there was a status.


We got our printer 3 days ago and we are experiencing the same problem with filament melting inside the casing.

We appear to also have been experiencing filament feeding problems aswell as the flux pressing to hard on the printing plate as described in these other 2 threads.
Oil/filter for filament: Filament Oiler/Filter - #21 by Nils-Ola
Printer head pressing to hard on plate: Print Head pressing plate too hard?

I was about to try and print a filter to see if that would alleviate out problems but now I’m worried about using the printer with all that melted filament inside.

I recommend having all Flux users check their print heads to make sure they don’t have build up happening after prints. If this happened to me and Sashagg, I am certain additional Flux users are going to be experience this exact issue. I haven’t heard anything yet from the Flux team, I feel like just sacrificing it and opening the print head up to see exactly what is happening, but I want to make sure at the very least I can buy another print head.

I just replied the issue here:

Perfect, I was worried that by opening it, it would void the warranty. I’ll clean it up once I have some time and post an update. Thanks for the update on this @Jim .

As promised, here is some images of trying to clear out the filament.

Cleaned off a bit before the tare down

Huge mess inside

Melted Lower Cover

All put together…

Looks like this may need to be sent back. There is some additional filament inside the head that I’m unable to get to get too from the bottom. I can say that the nozzle is tight and not pushing filament out from its side. The more I look at it the more I think it may have been a scenario that the head was constantly smashing the plate with hot filament pushing up, this is just a theory anyways. A fail may have happened in the middle of the print head, but I assume that the middle is solid with no possible points for filament to seep through, unfortunately again I am not certain, since the top has board which looks very sensitive and I would hate to start tearing it down further without some kind of backup.

It definitely looks like the threads between the heater block and the heat-break came loose. That plastic is coming from about the highest point that gets hot enough to melt it.

auch… looks even worse inside before you got it cleaned out.

Got mine cleaned out last night, but mine wasn’t as bad off as yours.

  1. I used the feater “change filament - unload filament” to warm up the PLA and clear inside the nozzle.
  • after this i was able to get the lid off which had been stuck to the PLA.
  1. Removing solid PLA, not fun. I tried warming the PLA in hopes of removing it easier from the casing. The Nozzle was mostly untouched after the “unload filament”.
  • I tried boiling water for heating - didn’t do much
  • I tried using my hairdryer, it was slow but it did make the PLA slightly pliable so I got most of it off…
  1. Reasseambled and did a test print, first print didn’t stick on the plate so stopped it and redid the setup. Second print was Perfect though it does sound like it has a filament feeding problem(tick, tick, tick) but Now I have an filament oil filter and looking forward to trying another print with that tonight.

Glad to know when can open the casing and clean it out without voiding the warrenty :slightly_smiling:

1 Like

I had the same thing happen to me. I’m starting to disassemble it now…

My nozzle seemed tight, but I didn’t dig any deeper than that. Has anyone disassembled it further than the cover to see if there’s anything else to tighten?

My cover melted a little bit and I couldn’t get all of the PLA out from around the hot end. Hopefully it’s close enough.

I’m not exactly sure when this happened to mine, but I noticed it after a print came loose mid-print. My initial thought was that mine happened because the print didn’t stick and filament piled up by the nozzle. A heated bed sure would be nice.

Here are photos from my teardown…

Can I use your photo as a demonstration for fixing printhead PLA permeation? We are addressing this issue as well.

Yes you may.

I did a couple prints after I finished cleaning it out and it’s still not printing well. Only a little bit is coming out during the skirt and its printing unevenly after that.

One thing that would really help troubleshooting problems like this would be direct controls of the printer in Flux Studio. Being able to set the head temp and operate the extruder manually would be very nice.

1 Like

Do we know why this happens? If my printhead is going to do that, I would rather not use it/update it with the correct settings! :slight_smile:

One way to get some more filament to come out once you’ve cleaned it up is to set the print temperature to something high 220-230C, start a print (that you’re going to throw away) and after it’s heated up and going, double-push the Flux button to pause it. The print head will keep its temp, and some of that extra filament will slowly melt out over an hour or 2.

@22minnis22 - I haven’t had it happen to this degree, but when it does happen, it’s always a case of a print going wrong (due to the unpredictable nature of 3D printing) and me not monitoring the print properly.

1 Like

Just got my printer yesterday and i ran into this issue on my second print:


Ours continued to print unevenly as well.
The flux team has sent us a new printerhead and it is coming through the customs right now.