@oliof That noctua has been there for almost half a year and there were no issues with it.

@infiniteloop So...today I got back to troubleshooting after leaving my printer alone for a few days so that my frustration would go away somewhat. I also picked up the phaetus dragonfly bms hotend today and put it in my printer.

I set it up and everything, bought a new generic ptfe tube (no fancy capricorn stuff) and after I put everything together I started the print...and yet again...the issue was the same...I couldn't believe my eyes...I was in utter disbelief...how, what, why...I have changed everything, there can't be any issues...I even pulled the ptfe tube out and put the filament in directly to check if there was any clogging, but there wasn't. And then...when I clicked on extrude on the duet surface, I heard the extruder stepper moving, but the gear didn't turn...then it hit me: I have upgraded the extruder part with a metal kit, which included a new gear for the extruder, but instead of the factory pressure fitted one I now had one with two miniature screws...which I didn't tighten strong enough, which (sometimes!!) led to the gear slipping...not always, just randomly.

So, turns out that I have been very negligent when putting the printer together the last time, it could've been one mistake or multiple failures at once which caused the print failures.

At long last, I can finally present a fully printed test cube! I really hope that this is where this story ends and that – at least for a while – I can print my creations in peace again.

Thank you @infiniteloop ,@oliof , @Exerqtor ,@jay_s_uk and @deckingman for the help and keeping the spirits up!

@infiniteloop I'm back after some rest and I can gladly say that this saga ends here.

I realized that wiring it straight up to the board fan wasn't a great idea, so I configured two separate fans: one of them is the part cooling fan and one of them is the hotend+board fan. The latter turns on when the hotend reaches 30°C, which means both the hotend and the board gets cooling whenever there's job to be done. The part cooling fan works as intended, I just separated it from the hotend fan.

I dare to post these results after 4 test prints, all of which were successful with no issues whatsoever.

I thank all of you, especially @infiniteloop and @oliof. Because of you guys I now have an insight which I didn't before and now can troubleshoot much more stuff on my printer as before. There's always something new under the sun I guess.

@infiniteloop
Okay, so... I have made so many amateur errors that I can't even comprehend how I made these mistakes.

First thing is, that during the reassembly I forgot to tie the hotend down properly and it was wobbling like crazy (I have no idea how I didn't notice that before...), no wonder I had layers shifting all over the place

Second thing was that during reassembly I probably pulled a bit on the ptfe tube, which pulled it back like half a centimeter, which caused heat creep and got the filament stuck all the time.

I took the whole hotend apart and thats how I discovered the issue.

Moral of the story: after a major rebuild ALWAYS double, triple, quadruple check everything. Luckily I had a new ptfe tube which I could replace and nothing clogged/broke/strained to the point where its unusable. I'm printing a calibration cube just to be sure everything is in order.

@infiniteloop @jay_s_uk Thank you both for the help! After some troubleshooting I found out that the top two rollers in fact DO have some dimples on them, so I ordered new ones from aliexpress. Also I made sure to balance the bed as well as I can. I hear a bit strange sound sometimes during printing, like someone was pounding on the table very slightly, but I couldn't identify the source.

Anyways, now the printer works well enough, of course because of the rollers there are imperfections, but I hope those will go away as soon as I install the new ones.

Thank you once again!

@infiniteloop I'm back after some rest and I can gladly say that this saga ends here.

I realized that wiring it straight up to the board fan wasn't a great idea, so I configured two separate fans: one of them is the part cooling fan and one of them is the hotend+board fan. The latter turns on when the hotend reaches 30°C, which means both the hotend and the board gets cooling whenever there's job to be done. The part cooling fan works as intended, I just separated it from the hotend fan.

I dare to post these results after 4 test prints, all of which were successful with no issues whatsoever.

I thank all of you, especially @infiniteloop and @oliof. Because of you guys I now have an insight which I didn't before and now can troubleshoot much more stuff on my printer as before. There's always something new under the sun I guess.

@infiniteloop I've wired the hotend fan to the board fan, which also turns on at 45°C.

Seems like the biggest failure in this rebuild was me. Never mind, at least now I'm (almost) completely aware of how and why my 3D printer functions and hopefully I can troubleshoot almost anything that happens which is extrusion related. Thanks again!

@infiniteloop Yet again, I must say that I did something really stupid, which I just came to realize....

So...the thing is, that to make my life easier during wiring, I put the part cooling fans and the hotend fans on the same step down module...which means that unless I manually turn the part cooling fans on, the hotend fan won't be on until like the second-third layer or so...which I guess is plenty enough time for a clogging to happen, but correct me if I'm wrong.

But anyway, yes. Extruder stepper motor is working, motor gear fixed in place, marked with a sharpie to know if its slipping. Ptfe tube check, hotend is good, coupling is good. I've tried different PLA-s, Gembird, 3D Jake eco PLA and filamentum. Hotend was set to 220°C with the filamentum one and 210 with the gembird and 3DJake.

@infiniteloop I cheered too soon...

Now that I started printing a part that I made, I started having problems.

It seems like I've got some heat creep going on, however, I can't reproduce the issue manually. I already set like 0,5mm retraction, I have the same result.

I tried pushing the ptfe tube as far as I can down the hotend but it won't go any further...

@oliof That noctua has been there for almost half a year and there were no issues with it.

@infiniteloop So...today I got back to troubleshooting after leaving my printer alone for a few days so that my frustration would go away somewhat. I also picked up the phaetus dragonfly bms hotend today and put it in my printer.

I set it up and everything, bought a new generic ptfe tube (no fancy capricorn stuff) and after I put everything together I started the print...and yet again...the issue was the same...I couldn't believe my eyes...I was in utter disbelief...how, what, why...I have changed everything, there can't be any issues...I even pulled the ptfe tube out and put the filament in directly to check if there was any clogging, but there wasn't. And then...when I clicked on extrude on the duet surface, I heard the extruder stepper moving, but the gear didn't turn...then it hit me: I have upgraded the extruder part with a metal kit, which included a new gear for the extruder, but instead of the factory pressure fitted one I now had one with two miniature screws...which I didn't tighten strong enough, which (sometimes!!) led to the gear slipping...not always, just randomly.

So, turns out that I have been very negligent when putting the printer together the last time, it could've been one mistake or multiple failures at once which caused the print failures.

At long last, I can finally present a fully printed test cube! I really hope that this is where this story ends and that – at least for a while – I can print my creations in peace again.

Thank you @infiniteloop ,@oliof , @Exerqtor ,@jay_s_uk and @deckingman for the help and keeping the spirits up!

@re_tour said in My printer stops extruding randomly, what am I missing?:

@infiniteloop I will look into the issue a bit further during this week, I have ordered the dragonfly, but that will only arrive on the next week. Until then, who knows, maybe I find the offending factor and can eliminate it. I will be back with updates and hopefully with a complete benchy!

After two failed attempts I let the hotend cool to see why the filament gets stuck and guess what! The ptfe tube has no molten pla in it. So whatever happens, it happens below the ptfe tube. Since the thermistor and the heater are working fine, I can only guess theres clogging...which is just not possible, I already changed the nozzle and saw no sign of residual pla in the entire hotend which could cause clogging.

If the issue will be the same with the dragonfly there may be some petrol and cigarette lighter involved in the following troubleshooting step.

@infiniteloop I will look into the issue a bit further during this week, I have ordered the dragonfly, but that will only arrive on the next week. Until then, who knows, maybe I find the offending factor and can eliminate it. I will be back with updates and hopefully with a complete benchy!

@infiniteloop Alas, failiure. Around layer 40 it yet again got stuck inside the tube and couldn't move further down the hotend. I've had enough with this hotend, as @oliof said I'll try the dragonfly and see if this keeps occuring with that hotend also.

Deep breaths.

@oliof To be honest the tube came with the machine, I just dug it out of the box and changed the old one. I had my suspicions tho that it may be a crappier replacement, since the one which was fitted to the hotend looked different.

I bought a new coupler as @infiniteloop pointed out that it may be shot(which it absolutely was) and now I'm printing a calibration cube. I don't want to jynx it, but so far its seems to function normally again.

The cooling fan is a noctua 10x10 fan with a step down converter, which I don't think is an issue(but I've been wrong before sooo...)

I may buy a dragonfly if I have this issue again though since the coupling cost me 5€ and the dragonfly is around 40€ but would eliminate this kind of problem altogether.

Thank you for the tips!

@infiniteloop Seesh the coupling is done for. I can just pull the tube out with no resistance at all. I'll be ordering one asap, will post results when that arrives.

Thank you for the help, I'll update as soon as I can!