Robert Górski

I'm quite sure that the third fan is working. In fact, it spins so fast that its hards to see if it is rotating at all. About retraction distance - I think it's set to default value in my Cura profile. I don't know if the residues are parts of broken strings created while replacing filament to new spool - but it may be the case... I think I must see it for myself. Is there a instruction for disassembling printing block?

More info. My first printer came back from service. It works OK now. I was informed that: - nozzle was cloggead and it was cleaned - teflon coupler was quite OK, nevertheless it was replaced - there was many residues of filament in printing block (above teflon coupler) and most propably it was the major problem. The service guy told me that is a case of not-so-good quality of the filament I use. This last thing worries me much. Where the residues come from? Are they scratched pieces from the rear filament providing block and they travel via bowden tube? Should I clean the printing block myself? Can you point me to instructions how to do this?

Thank you very much for your answer. I follow your advice and I did the cold pulls (atomic method). It looks like there is not much of a burned PLA, dirt or dust or whatever there (see photo). So, I checked the diameter of the teflon coupler. After unscrewing the nozzle I tried to push the 3 mm drill from below with the blunt end, which, as I measured, has 2.9 mm diameter. And it not fit - it wont go. I cannot say how much the coupler hole was smaller, but it was not much, maybe about 0.2 mm. So I drilled it with 3 mm drill. After all of this cleaning and drilling I must say it got liitle better. It's not like new, but I can see positive difference. I read somewhere here, that even 4 mm drill can be used. I wonder if I should use 4 mm drill. The other printer (the older one) is still in service. I was told that the clogged nozzle was cleaned and the coupler was changed to new one. In few days I will get the printer back and check if it solved my problem. Anyway, again, thanks for your help.

Hello, This is my first post here, so, hello everybody! I own two Ultimaker 2+ printers and I stumbled upon the same problem on both of them. When the printer is new, it prints excellent, but after about one month of heavy using (like 6+ hours per day) it begins to underextrude. It happend to my first printer - I send it to servicing company, they lubricated it and returned with conclusion that there is not a problem with a printer. I bought another Ultimaker 2+ and the new one works better. It prints the same gcode file as old one with much better result. But after one month it started to do the same - underextrude. The lines of filament spilled from a nozzle get thinner from print to print and eventually they begin to not stick to the very next parrallel line of filament. I can see that there is a problem right away after printing starts. At the very begining of the printing process the printer spills a "noodle" of a filament in the left close corner of the printing table (before even the moving the printing head). When the printer is new, the noodle is thick, its even twice as thick as the nozzle width (in my case is 0.4 mm). Now, the noodle diameter is about nozzle diameter width. Something creates the problem and: - its not like blocked/dirty nozzle - it happens with newly replaced nozzle also. - its not a gcode file problem - when printer is new it prints the file with excellent quality. - I use the same filament from the very beginning on both printers - it is not a problem with filament quality. Can you point me to things I should check? Did you have the same problem? Regards, Robert