Printer Head bottom cover started melting


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.

Replacement nozzles? Printing with abrasive filament
How to disassembly the 3d print head? - solved

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:


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.


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.


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.


After four months of printing and most of the print temperature is at 195C, the calibration is faulty all the times. When I tried to clean a nozzle and saw the cover was melted but no melted filament filled inside. I submit a ticket for replacement tool head.


Me too. Once they get the store fully running I hope this is one of the consumable parts for sale.


Here are the reference images of 4 months old (my tool head), that is failed on calibration, and new printing tool head, which is provided form Jim, Flux engineer.


Nozzle appears to be recessed a lot more. That is what my stock tool head looks like.


My stock printhead also has this more recessed nozzle. No signs of melting or deformation so far…


The other day I started smelling a burn smell. I looked underneath, and saw the same thing that you have a photo of. The plastic bottom started to bubble. I took it off and the bottom of the case was melted. I heated the extruder head, and cleaned off all of the burnt plastic, I also changed the nozzle to a new nozzle. I have not tried to print anything else as of yet, I will hopefully tonight.


A heat element (aluminum block) of my tool head which was loosen from heat sink that was pushed nozzle down further. I think while I was opened the adapter, which hold PTFE tube, the parts also lose at the same time.


When I took the cover off, everything was tight. the extruder block was shifted not in the center, so I moved it so that it was center. I printed last night, and so far no issues. I do not know if the issue was because the heater/nozzle were shifted out of center or not. Time will tell.


You are exactly correct from my experience Jim. I had one replaced by FLUX and completely disassembled it. Sometimes (due to overtightening) the top silver bolt where the white tube feeds into the hot-end gets over-turned. This causes 2 bad things tend to happen. 1. A tiny gap in the threads between the heater core and bowden tube causing plastic leaks, or worse… 2. The hot-end starts to creep closer to the black hard outer shell causing the bottom shell to melt.

When that happens, open a window quick. That plastic stinks real bad.