Printer randomly extruding blobs of burnt filament
I have recently upgraded my mk2 to mk2.5s. Prints over the first few weeks were fine, but recently almost all prints are failing because the extruder randomly extrudes blobs of filament that looks burnt. In some cases, the print will complete, but with visible burnt spots, but in most cases, the extruder will crash into the extruded blob and cause the belt to skip.
I used the PTFE tube that came with the mk2.5s upgrade kit.
The nozzle is a E3D V6 0.4mm, also purchased from Prusa. I've checked that it is properly tightened.
Any ideas for what could be wrong and how to troubleshoot? Picture of a recent print attached.
RE: Printer randomly extruding blobs of burnt filament
I forgot to mention that I am printing with Prusa PETG, standard settings in Prusa Slicer. The model in the picture has 90 % infill, but it happens for other infill settings too.
RE: Printer randomly extruding blobs of burnt filament
I'm still guessing that the nozzle is leaking. The material flows down on the outside of the nozzle slowly, burns and after some time is wiped of to the printing surface. Observe the nozzle while printing or make a photo of the nozzle, or just check that material is on the outside of the nozzle.
RE: Printer randomly extruding blobs of burnt filament
Hi,
If it is the same problem which i had a few months ago. There were some blobs all over the nozzle. They fell down on my printing area.
Look on the video
RE: Printer randomly extruding blobs of burnt filament
I have this exact problem on my XL, but that uses the long nextruder nozzles, they should not leak, right?
RE: Printer randomly extruding blobs of burnt filament
Is filament building up around the tip of the nozzle?
this may indicate over extrusion.
if so, try reducing the flow rate a little during 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
Pay particular attention to the diagrams at the bottom of this page:
https://help.prusa3d.com/article/changing-or-replacing-the-nozzle-mk2-5-s-mk3-s-mk3-5-s_2069
Cheerio,