"Filament stuck" errors every 15 seconds.
I recenlty assembled an MK4S kit. I printed several prints, including some big ones with no issues. I'd say about 20 or 25 prints over 3 or 4 weeks. I've printed in PETg, PLA and PLA+. I'm using the MMU3, but the kit came with the CHT nozzle altough it's not recommended. However, chat support told me the only difference is I should increase the wipe tower when printing in multimaterial.
However, a few days ago I started a print (single color), checked that first leyer was ok, and then left, when I came back the printer had only printed a few layers and was waiting on the "filament seems to be stuck" error screen. It was exactly the same gcode I have printed a few times already with absolutely no issues.
I did the unloading/loading routine and it resumed the print, but same thing happened again after a few minutes. Since then I've tried over 15 prints, and I've only been able to finish one, which I had to babysit through ~30 "filament stuck" errors. Every time the filament unloads and reloads with absolutely no problems, and print resumes for a while. Sometimes a few minutes, sometimes barely 5 seconds, before triggering the error again.
If I turn off the stuck detection, it's evident that it is not a false positive, as the filament eventually does get stuck and stops flowing altogether. However, if the detection is on, the uloading/loading occurs with no incidents every single time, and the purging always flows freely.
It USUALLY goes through the first solid layers, and the problem starts once it starts with the infill, altough it did get stuck once or twice on the first layer.
So far I've tried, with aboslutely no success:
-Loosening the idler tension screws
-Tightening the idler tension screws
-Loosening/tightening the MMU3 cover tension screws (although once the nextruder is engaged, the MMU3 sits idle)
-Switching to PETg, PLA, PLA+, trying different spools, including freshly opened ones.
-Cleaning the nozzle in place, using the needle that came with the kit, and also with another nozzle cleaning set.
-Taking the nozzle out and thoroughly cleaning it with the needle by heating it with a heat gun and also on the stove.
-Reslicing the piece with different profiles, both for the (CHT) high flow nozzle and the regular one. Also tried profiles for the MK4S without MMU3 (but then again, the only difference should be in the first loading part, since the print is in single material and the MMU3 sits idly).
-Different prints of various sizes and shapes.
-Increasing the nozzle temperature. The PLA+ I'm using is advertised to print in the 180-250 range, before this problem started I was printing at 215, I've now tried everything from 215 to 250). This seems to be the only thing to have a slight impact on performance, as it appears the problem is slighlty less frequent at higher temps).
-The "cold pullout" routine several times.
-"Manually" (settings/move extruder) extruding lots of filament, changing colors to check that no specks of previous color ever came out).
-Reducing (80%) and increasing (110%) the printing speed.
I'm about to order a new nozzle to be 100% that there's nothing stuck inside this one, but that will take a few days to arrive, and I don't have much hopes anyway, as purging works, first layers work, etc. so flow inside the nozzle really seems normal.
One thing that may be worth mentioning is that for that print that I did manage to finish after many many errors, the dimensional accuracy was hideous. The print surface quality is spotless (because the printer actually pauses on every error, and resumes flawlessly), but outside corners seems to "blob out", so a square looks more like if a castle had circular towers on each corner. This only happens on outside corners (presumably in insides corners it's hidden inside the piece). It gives the impression that some filament built-up pressure is releasing on sharp turns and it overextrudes. Again, I printed the same thing a few times before and it was a perfect square.
I'm absolutely at a loss. The printer is unusuable, every single print fails. I don't know what else to try. Any help is GREATLY appreciated.
RE: "Filament stuck" errors every 15 seconds.
Hello,
I have exactly the same problem and have already done these steps (except for the nozzle). I have also printed 3-4kg of filament without any problems. And now I can't do a single print without this error.
RE: "Filament stuck" errors every 15 seconds.
What I also noticed: In the hardware settings in Prusa-Connect, high-flow was set to "off". But the MK4S has high-flow nozzles. I set it to 100% when setting it up. Maybe it went off after the firmware update? I set it back to ON, and it's been printing for an hour now. I hope it stays that way.
RE: "Filament stuck" errors every 15 seconds.
The thing is that is the firmware thinks you don't have a HF nozzle but you actually do, it shouldn't clog, but the opposite!
I mean, if the printers try to extrude high volumes thinking you have a HF nozzle and you don't, it's reasonable that it gets stuck, but not the other way around. In any case, I've tried slicing the models for woth HF nozzle and regular nozzle (I only have a HF nozzle, I ordered a regular one along with the replacment of the HF one), and it gets stuck all the same.
Yesterday I managed to finish 2 small 3-color prints with no errors, but trying it for the third time (exact same file) gave me 4 o 5 errors one right after the other, all while printing the wipe tower, then finished the print.
Even more, I had printed that same model a couple of weeks ago before this issue started, and then surface finish quality was WAY better. I did reslice since (unfortunately I deleted the old bgcode file), but haven't changed any settings except the model position. Now it seems that the surface is all bumpy where the colors meet, like it is overextruding the infill over the permiters. I tried lowering the flow multiplier from 100% to 95%, and the surface finish got a bit better but not much.
I'm now really starting to think this has something to do with a config file update. There were no firmware no slicer updates recently, but I'm quite positive I got the profile config update messages when starting Slicer recently.
I'll check the "high-flow" setting.
RE: "Filament stuck" errors every 15 seconds.
Well, I didn't have a high-flow nozzle installed, even though it said so on the box. So I suspect that the slicer settings were set to HF, but I don't have an HF nozzle, and that was feeding way too much filament that didn't fit through the nozzle. I've now changed the whole nozzle anyway, because swirls kept forming when I "flushed". I just started a print that kept giving errors. I'll report back. I'm pretty sure now that it was the nozzle.
RE: "Filament stuck" errors every 15 seconds.
Hopefully that was the case and it will be fixed for you. Still doesn't explain how you printed 4kg of PLA without any issues before, in the same way as I did print probably over 3kg of both PETg and PLA. I still think this is software or firmware related, altought it might be something involving a mismatch between hardware and software that got changed somehow at some point.
In my case I do have the CHT nozzle (I took it out ans checked), so until the new nozzles arrive there's not much else I can do.
RE: "Filament stuck" errors every 15 seconds.
Since I replaced the nozzle yesterday, the printer has been printing without interference until now. About 12h. So it must have been the nozzle, although nothing was visibly broken there.
RE: "Filament stuck" errors every 15 seconds.
Thanks for the update. I´m still waiting for min to arrive. This "swirls" you mention, happened when you purges filament? One thing I notice is that whenever the printer purges (wither when doing the automatic procedure, or when doing it manually by making th extruder motor move from the menu), the filament curls UP and sticks all around the nozzle instead of hanging down like it does on my MK2.5S. At first I thought this was caused by the payer fan, but it happenes even when it´s off. I suspect it might have something to do with static electricity building up on the silicone sock? I have yet to try without it.
I hope it´s just something broken or stuck inside the nozzle and that it will be fixed with the new one. Still, it´s very alarming that a nozzle would clog like that just from regular printing and only about a couple of kgs of filament.
RE: "Filament stuck" errors every 15 seconds.
The curling of the filament at the nozzle occurs when changing the filament and also when extruding manually. I looked at the nozzle under the microscope and you can see tiny irregularities around the exit hole. I suspect that I damaged the brass nozzle while cleaning it. This no longer occurs since replacing it with the same silicone sock. So I rule out electrostatics.
RE: "Filament stuck" errors every 15 seconds.
We seem to have experienced exactly the same type of failure. I now can't recall wheter I cleaned the nozzle at all BEFORE this issue started, most likely I got a genuine sutck filament error, the proceeded to clean the nozzle and in that process damaged somehow. It's still very odd as I only used the provided nozzle cleaning needle, and never forced anything so I don't know how I could have damaged the brass nozzle, but the symptoms are consistent with what you describe. I am now very worried about what to do if the new nozzle ever gets clogged, if using the cleaning needles (of which I ordered a few as well) produces this catastrophic results.
Is the new nozzle still working without issues? Mine is supposed to arrive on wednesday, I hope it will solve the issues.
RE: "Filament stuck" errors every 15 seconds.
Received my new nozzle today. Just installed and it purges with no curling, started a print and the first layer looks much sharper in the corners, so this is promising. Will report later!
What I did is also buy the nextruder-to-standard-e3dv6 adapter, so in case this happenes again I can swap just the nozzle itself (which I can get locally) and not the whole barrel.
RE: "Filament stuck" errors every 15 seconds.
4 prints completed (albeit rather short) with no errors and perfect quality since swapping to the new nozzle.
Examining the old one (old is a bit of a overstatement, as it didn't have more than 20-30hs of printing) I can see the hole is not round, and a bit stretched, so that was obviously the issue. I'm still absolutely lost about how it could have been damaged that bad. I'll try to drill it with a precision bit and transform it into a 0.6 nozzle.
RE: "Filament stuck" errors every 15 seconds.
just wanted to comment that I had the same issues. Had my MK4 since Feb24 and upgraded to the MK4S, I'm not advanced but not a beginner anymore.
Same as above: the MK4S upgrade with HF was going great, I had net less failed prints overall, and everything was finishing smoother.
after a couple of weeks of GREAT prints, switching between Overture PLA and Prusament PETG I started getting the stuck filament error. cold pulls, cleaning-nozzle, switching filament, drying did nothing for me. I tried using compressed air as others have suggested. Nothing worked. I bit the bullet, opened up the nextruder to clean and regrease it. I found a skinny thread of filament in there. Successfully passed re-calibrations.
It didn't work right away, took maybe two reloads of filament for the stuck-filament errors to stop. But then I noticed my prints would fail about 15 minutes in.
Switched nozzle back to a regular 0.6 (not HF) and it's working nicely again with no stuck filament or issues. I believe I had a bad clog in the nozzle from switching filaments.
Overture PLA is lower temp. I think in the future, I will only use regular nozzles with lower temps on it, and switch in the HF nozzles for specific projects.
RE: "Filament stuck" errors every 15 seconds.
Hello, I'm glad that it's working for you now too. I'll only use the normal 0.4mm nozzle from now on. I'll only use the HF nozzle on selected objects.