Hi guys. Please check my previous post for any background questions, I don’t have it in me to go over everything again.
Long story short, I was having issues with clogging that were being caused by my hotend not reaching the reported temp. After a few days of troubleshooting and diagnosing the motherboard and Klipper settings, I gave up and decided the motherboard was faulty (even though I could not perform any tests to determine in) and bought an SKR mini. I got that all set up, and the printer has been working flawlessly since then.
Until now.
Same exact problem; one print goes perfectly fine, next print, failing to extrude by the 4th layer. I removed the clog, restarted the print, now can’t even extrude the priming line. Fearing the worst, I disassemble the hotend, try hand feeding filament, and once again I am unable to push more than a few centimeters through before it gets clogged up. A probe thermometer reads ~160C while Klipper reports 200C.
What could possibly be happening here? The board is an aftermarket replacement from a completely different company, so I doubt it’s a recurring manufacturer defect, but I have no idea what else can be causing this.
At this point I’ve spent so much time and money trying to fix this printer that I could almost buy a new one, but at this point I’m not convinced even that would solve the problem.
It might be an issue with concentricity. If the nozzle is not perfectly centered it creates a step that the filament can snag on. It can then cause the already softened filament to bunch up during deretraction forming a plug in the heat break. I had this issue with cheap nozzles. Everything starts fine and after a few layers it all stops for apparently no reason. Cranking up the heat makes it better for a bit, before making it worse
Filament is not melting when held to the outside of the heat block. It is 100% an issue with the nozzle not reaching target temp.
Hrm, I had similar issues on my Artillery X2 before.
Here’s what I went through:
- Replaced the nozzle
- Replaced the thermistor
- Replaced the heating block
- Replaced the main PCB
- Replaced the heatbreak
Finally, I gave up, and took out the thermistor again thinking maybe I broke it. There’s a small PCB connected to it, that sits on the side of the hot end assembly. I contacted Artillery about a potentially faulty hot end PCB, they sent me a replacement. It did not help. Desperate, I also replaced the thermistor with the replacement one that was part of their repair kit. And that worked. I think the faulty PCB broke the first replacement thermistor or something…
Maybe I missed a paragraph but did you try a new temperature sensor?
That would seem like a logical error source for me when the reported temperature does not match the actual result. Or maybe there is an issue with the thermistor calibration? Is the thermistor type set correctly in your klipper config file?
Yup, went over those a few times throughout the posts, multiple thermistors, multiple ports on the board, several configs in Klipper. All of them identical behavior.
Small anecdote, but I was getting print failures a few layers in with thermal runaway as the error code (with tiny oscillations of temperature fluctuating at the target temp seen on octoprint) after replacing the hotend for all metal (bimetal heat break, CR-10 copper block, screw in NTC 3950 thermistor) on an Elegoo Neptune 3 Pro. Turns out that the little silicon cover for the block was missing, and replacing it completely solved the issue.
I skimmed the posts, but couldn’t quite locate if the issue persists if you leave the printer alone for a few hours/days and then come back to it later. (As in would it be able to complete a print before exhibiting this issue again) Seeing how it worked fine before and doesn’t anymore, especially if in a consistent matter, irregardless of settings, might be a chance you blew a capacitor and it’s trying its best to cope with that situation. Unfortunately without replacing the board with a confirmed working one it’s hard to tell if that’s the case… plus depending on the level of damage it might appear as intermittent problems that sometimes manifest without rhyme or reason on 2 potentially identical prints.
