medveybo

I'm pretty sure the problem is not the bowden plug. I have written it before, but I can get the extrusion back on track simply by pulling out the filament and trimming the deformed hot end. After that, when I push it back extrusion is suddenly good again. If it was a bowden plug I suppose it would need a bigger effort to fix. I sometimes do this even during print, because if I notice the problem right away, then I can do the correction before it finishes the layer and it doesn't make much difference. But of course I cannot sit and watch over the printer every time... Anyways this problem has been quite unpredictable so far, and yesterday we did a 4 hour print, which was almost "perfect" but once again the top layers weren't printed because of extrusion failure.

Okay, so extrusion stopped much faster on the second run. I tried lowering the temperature to 190: extrusion was very diverse, sometimes normal sometimes really low without me touching it. It never fully stopped though as before, but I eventually aborted the print, because it would've been useless. I'm getting really tired of having a problem, reading the forum and feeling like 'oh now I understand what is happening', I go and fix it and the same thing happens again and I have to face it, that I DON'T understand what is happening. Does anyone have any idea of why extrusion might be failing like this? Or even what symptoms I should look for to get closer to identifying the problem?

Thanks for the tips, I could clean the heated tip with a really thin wire. So the total blockage has been solved. I almost had my first print without a problem, but extrusion stopped again on the last 10 layers. After unsuccessfully trying to print again, some extrusion by hand and trimming the hot end of the material extrusion was normal again. I just started the project again, we will see what happens. I'm beginning to suspect, that it is actually the heat creeping up the bowden tube, melting the material which in turn gets thicker and thicker at the end, and eventually the extruder motor cannot cope with the situation. This sounds reasonable, because the problem is usually solved by trimming the hot end of the material. Although should this happen with 220 degrees and one hour long prints? I would've guessed this problem occurs at higher temperatures and longer prints.

Hi guys, I have been reading the forums for answers for a week now. We assembled our Ultimaker machine last week and I have been trying to find the right configuration for black PLA, but I haven´t been able to produce one decent print. The problem usually was that extraction stopped during prints. I tried everything I could find on the forums concerning this matter (including changing the pressure at material feed end, finding the right temperature and today I had my first plug that I removed after dismounting hot end). So far I could solve most of these problems with the help of the forum, but the mysterious change of extraction rates didn´t stop and is still without any explanation. Today I almost had a perfect print, but just before reaching the last 5-10 layers the printer stopped extruding again. Right after the print I tried extruding by hand, which seemed to work - for a short while. After that it stopped and has never restarted since. Practically nothing comes out of the nozzle, even after dismounting, cleaning every piece and assembling again. With unused PLA there seems to be no friction in the bowden tube, so I assume the source of the problem is not there. I even tried heating up the nozzle without the PEEK on, but nothing came out of the nozzle. I made an attempt to clean it from the other end and letting it drip out that way, but that didn´t help either. Although one curious thing happened: melted PLA was coming up from between the heater and the brass tube. (see picture) Anyone experienced this before? I´m starting to think that the nozzle got blocked from the inside. What can I do? I would be grateful for any suggestions as to the next steps as well as for the reason of the previous extrusion stops.