Strange black blobs with an orange Filament
Hello,
since I have change the nozzle, I have strange black, or perhaps dark blu from a former filament (?), blobs in an otherwise perfect printed part. What couild be the reason?
Thanks in advance,
Volker
Best Answer by JoanTabb:
Hi Volker, you probably didn't change the nozzle properly.
when assembled, the top of the nozzle thread, should butt up firmly to the bottom of the heatbreak threaded section.
frequently people make an error when changinfnozzles and thy end up with the nozzle hexagon body tight against the heat block, and a tiny gap between the nozzle and the heatbreak, this allows molten filament to escape up the heat block threads and it leaks out over the top of the heat block, where it proceeds to fall at the most inappropriate times, and contaminate other jobs.
often causing collisions or layer shifts.
RE: Strange black blobs with an orange Filament
Hi Volker, you probably didn't change the nozzle properly.
when assembled, the top of the nozzle thread, should butt up firmly to the bottom of the heatbreak threaded section.
frequently people make an error when changinfnozzles and thy end up with the nozzle hexagon body tight against the heat block, and a tiny gap between the nozzle and the heatbreak, this allows molten filament to escape up the heat block threads and it leaks out over the top of the heat block, where it proceeds to fall at the most inappropriate times, and contaminate other jobs.
often causing collisions or layer shifts.
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
... and bear in mind that some cheap nozzles are a fraction too short in the thread. Prusa use E3d nozzles.
Cheerio,
RE: Strange black blobs with an orange Filament
I've screwed off the nozzle, cleaned the heatbreak and fixed it again. It looks quite better! Thanks a lot!
RE: Strange black blobs with an orange Filament
Excellent!
Happy Printing
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Strange black blobs with an orange Filament
Can the nozzle also get loose over time? I have a MK3 that has been printing for about two years and I've started getting these black blobs (not as severe as the ones shown in the picture - they are about 2mm across). I've never changed the nozzle. I did have a print fail a little while ago where the print came off the bed and was dragged around the bed for a short while before I stopped it, so maybe some filament got up on top of the nozzle then and is still coming down. It has been quite a few prints now and I'm still getting it.
Just asking to work out if I should persevere a bit longer to see if it clears up or if I need to disassemble and reassemble the hotend (and if it is worn, will I even be able to reassemble it properly or do I need a new hot end)?
Can the nozzle also get loose over time?
It's unusual but not unknown, commonest when the nozzle is non-standard and has a different thermal expansion curve to the heatblock.
I have a MK3 that has been printing for about two years and I've started getting these black blobs
The expected life of a standard nozzle when printing hard with non-abrasive filaments is about 6 - 9 months ...
Cheerio,