Weird inconstant extrusion

[jarred 0]

Hello I have bought an Ultimaker original plus and It has been nothing but a dream. Recently I have been having an issue with extrusion, the filament is hard to push trough the nozzle as if there was a jam?. I have gone trough and cleaned the nozzle assembly and the nozzle three times. I know for sure that it is not the feeder, and when doing "cold pulls" it looks as if the heat is creeping up the heat break and the filament is expanding in the chamber.This has never been an issue and now I can no longer use the Ultimaker . The printer is stock and nothing is burnt or looks broken. I have already gone through all of the steps on ultimakers site

Edited April 27, 2019 by jarred

[geert_2 557]

I don't know the UMO, but on an UM2 there is a little fan at the back of the nozzle, cooling the seam between nozzle, teflon coupler and bowden tube. Probably there is one on the UMO too? Did you check if this little fan is running at full speed? If not running at all, or if too slow, heat would indeed creep up into the filament, melt it above the nozzle, and make feeding and printing impossible. The fan could be worn-out, or it could have sucked-up strings or hairs from prints and gotten stuck, or a cable came off?

 

[ahoeben 1,948]

The UMO does not have this fan (the UMO+ does).

[ahoeben 1,948]

It could be that the teflon (PTFE) coupler has been deformed over time. This is the white part between the PEEK part and the bowden tube. The head is fairly easy to disassemble. Take out the white part and inspect it. Use a small screwdriver to (gently) feel if the channel is still straight or if it has a bulge or severe discoloration. It may need replacement, it is a $15 - $20 part.

[jarred 0]

14 hours ago, ahoeben said:

The UMO does not have this fan (the UMO+ does).

the only thing is that the part cooling fan was damaged so i replaced it with a fan that is 10mm smaller but do you think that this is the issue? I have redone the teflon tube and checked the white rubber peice and it seems to be fine?

[jarred 0]

15 hours ago, ahoeben said:

It could be that the teflon (PTFE) coupler has been deformed over time. This is the white part between the PEEK part and the bowden tube. The head is fairly easy to disassemble. Take out the white part and inspect it. Use a small screwdriver to (gently) feel if the channel is still straight or if it has a bulge or severe discoloration. It may need replacement, it is a $15 - $20 part.

I noticed that the bracket that holds the brown piece and the white boden holder gets hot, I feel that This is a heat creep issue what can cause that? too tight when I reassembled the machine?