Extruder head issues


Hi Guys,
my flux arrived this week, I set it up on the bench and ran a couple of test prints (in white) through it. First thing i noticed was that there are burn marks (browned plastic) in the print, I’m using the supplied PLA so I’m guessing this is because of the second issue.
The second issue i discovered was that filament is building up inside the print head, not around the nozzle but actually inside. I’m guessing that something inside the print head has come apart. I’ve raised this as a support request about 3 days ago but had no response so i thought i’d ask on the forum, I’ve attached a photo of the bottom of the print head to illustrate the issue. Any ideas what i can do?


Clogged printer toolhead

Perhaps I should add, the mesh at the bottom is warped, like it’s been heat distorted in one place.


The only thing to do is try to clean it out as best you can. Do the Unload filament feature to heat up the nozzle and start cleaning it as much as you can. Then you will have to pop out the cover to get to the inside and clean there too. Check the nozzle for leakage and/or anywhere else that you might think.

I had that issue (sort of) when I didn’t tighten the connector on top of the print head where the filament enters. Slightly loose and the filament was oozing out. Luckily I caught in time and only had some slight warping to bottom.

After you clean everything out, tighten (but not too tight) everything, make sure the nozzle head is completely clean inside and out.

My only advice…


Thanks Kevin_Anthony, I’ll hold that advice in reserve until Flux reply to me, I’m not risking voiding the warranty.
Looking at the tool head it doesn’t look like the filament came from the connector, but instead has welled up from a leak between nozzle and somewhere inside the heater. I really think this is an RMA worthy claim. I’ll give it until tomorrow and then if Flux don’t respond I’ll start a DHL claim as it has arrived damaged.


Opening the print head won’t void your warranty. Only opening the printer base to get at the electronics will. I had a jam in my nozzle that was causing terrible print quality. As Kevin said, you just have to heat the head up (I used the filament change process) and then unscrew the nozzle. I ended up pulling out a chunk of filament that had become caught.


No disrepect gents but that is not what it says, it clearly states that here

So aside from cleaning excess from the outside, nozzle etc i’m not touching this until Flux tell me to


Check that the fan blowing on the heat brake is spinning. I had a problem with that and Flux sent me a new print head. They haven’t explained what was going wrong but I suspect the filament was too liquid going up into the tube.


Probably need to be more specific.

There are three fans. Two are squirrel cage fans that blow cool air on the extruded plastic filament after it leaves the nozzle. The other fan is a 30mm 5v fan like you would find on a video card cpu. This is the fan that you want to hear spinning anytime the extruder is over 100c or so.


Fair point. Although, considering the consumable nature of an extruder nozzle (it is brass after all and will wear with use), Flux better think twice over cancelling warranty for simple printer maintenance.


Darcy, I agree, the whole 180 days warranty things is pretty poor especially given the 16 month wait and the price compared to similar printers.

Tim I’ll check the print head tomorrow morning to see if all the fans are spinning. TBH I think the fan you mentioned worked fine because during both prints I’ve tried I could hear a fan spin up as the extruder came up to temperature


I’ve had the same issue with the extruder head clogging. Waiting to hear back from Flux 3D with how they would suggest proceeding. Had melted PLA come out the bottom of the head on the second print.

Hopefully we get some good news soon.



Ok so I followed the advice from @Jim that @Jimustanguitar linked above. Got the 99.9% of the filament out but there’s still a small amount smeared on the extruder head that seems burnt on. Next question is as the base plate has warped from the heat how do i go about getting this replaced?



If you make an RMA for the Flux team they will be able to send you a replacement.
The warped outer casing shouldn’t make problems for you unless it goes all the way down to the printing-plate.

My printerhead had taken dammage internally from the melted filament and we ended up getting a replacement through an RMA. Just go to https://flux3dp.zendesk.com/ and submit a request.


Mine is doing this now after they said they repaired it. What did you have to do? What did you do to make it work again?


My bottom of the extruder has melted as well, such that a big chunk of it fell off. The extruder is tight, so it is not moving around.



The print head on mine has done the same thing now. I’ve had mine since June and never had an issue, but wasn’t really printing that much. I was trying to print some small toys for my daughter for Christmas this last week and the software refused to put down substantial rafts around them. I tried to print several times and all failed. I have a feeling the run that melted my print head was due to this, one of the prints likely came loose and stuck to the end, then clogged it and then the whole head just filled up with molten PLA. Waiting on some kind of response from Flux team, but don’t expect much since I am out of warranty. Pretty frustrated with how few prints I got out of this thing, considering the price.


My printing tool head melted again…

No way…


I ended up taking the whole printer head apart, to expose the heated extruder head. I then reconnected the wire harnesses and turned the unit on. I think I used change filament mode to heat the extruder head, and remove the filament that had been deposited in the printer head. Be careful, as the extruder head gets to be about 200° F. That’s what I did, the wire harnesses are delicate. Not sure if you want to attempt this or not.


I had problems with filament leaking through after cleaning the nozzle after it had been been clogged. it appears the little double-ended screw thingy holding the radiator to the aluminium block the nozzle is on had come loose a bit, as I could see where the plastic had been oozing out of the thread on top of the block when I pulled the head completely apart. Needless to say whatever warranty the extruder head had has now be voided … as some crazy person then proceeded to use pliers on the threaded shaft to tighten things up nicely and accidentally-on-purpose roughen it up that much that it really didn’t like going back together… needless to say there’s little chance that puppy is coming loose again now… excessive force was used to reattach/re-secure! :open_mouth: :blush: :wrench:

Needless to say I’m hoping someone suggests a … more technical manner of fixing that particular issue :laughing: