Blobs/Overextrusion with Prusament PETG
Hi all,
I've got a Mini+ which prints fine with PLA. However PETG doesn't work, I get random blobs that makes the print unusable:
My settings:
- Prusa Mini+, latest firmware (4.3.1) with approx. 50 hours of printing
- Prusa Slicer, latest version (2.3.0)
- Print settings for 0.15 mm QUALITY/Prusament PETG (see 3MF file)
- Prusament PETG
What I've tried/checked so far:
- Using filament fresh from the vacuum packaging to make sure it's not moisture
- Replacing the nozzle to make sure that it's clean
- Replacing the PTFE tube with a new one, as some report different lengths for that tube
- Checking that the extruder pulley is completely free of any debris
- Searching this forum 🙂
I do watch that some extruded filament adds up around the nozzle tip and at some point gets dropped at the print. Thats also the reason for the brown color of the blobs, as the excess filament has already been travelling around some times at the hot nozzle. I also see that when I pause the print, the PETG still keeps on extruding from the nozzle (for maybe 1 or 2 centimeter).
I would be really happy for any hint - it drives me crazy as I actually cannot print anything with PETG on my (nearly) new Mini+.
Many thanks for your support!
Julian
RE: Blobs/Overextrusion with Prusament PETG
did you re do, z calibration when changing to PETG?
If the nozzle is too low, the nozzle picks up whisps of filament, and then dumps them in the most inopportune locations.
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: Blobs/Overextrusion with Prusament PETG
Hi Joan, yes I tried a new first layer calibration (with PETG and the textured sheet). The excess filament also continuously adds up and drops (not just after the first layer), so that prints have multiple defects.
RE: Blobs/Overextrusion with Prusament PETG
Reeks like a live z issue, I agree with Joan. I suggest you use the “live z my way” method (just google it) rather than the built in approach. The other usual suspect is the nozzle not being tight to the heat break but what you described doesn’t sound like that.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blobs/Overextrusion with Prusament PETG
Reeks like a live z issue, I agree with Joan. I suggest you use the “live z my way” method (just google it) rather than the built in approach. The other usual suspect is the nozzle not being tight to the heat break but what you described doesn’t sound like that.
I'm still wondering how it could pile up multiple times, but I'll test it with Joan's files (guess that's what you meant) and report the results.
When I exchanged the nozzle, I tightened it with a torque wrench at 2.5 Nm, as Prusa's documentation says.
RE: Blobs/Overextrusion with Prusament PETG
I've printed PETG quite a lot with my Mini and I've had no issues so I can say with certainty the Mini can do it.
Are you using a known good brand of PETG? Have you checked your extrusion rates? If you're over extruding it could result in blobbing.
Regards
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE: Blobs/Overextrusion with Prusament PETG
@juls
With Live Z My Way I meant this method by Jeff Jordan: https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/, and while I haven't used Joan's files I'm sure they're fine.
With "tight to the heat break" I didn't mean to imply insufficient torque (2.5-3Nm is fine) but what the nozzle is tightened against. See https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/pla-melting-from-heat-sink-all-over-the-place/ for an illustration.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Blobs/Overextrusion with Prusament PETG
Im having the same issue now - but this is after using it for a year almost without issues, but then i took a break of a few months of printing anything and ive changed the Prusament PLA, i changed the nozzle, and changed the smooth spring sheet also - same thing keeps popping up
How did you fix this issue?
RE: Blobs/Overextrusion with Prusament PETG
When you say you changed your nozzle, did you use a real Prusa sourced nozzle? Many nozzles have the same pitch and thread of the Prusa but aren't the same length, if your nozzle isn't contacting the heat break correctly you can get blobbing like this. Have you take a good look at the nozzle change instructions, particularly how the nozzle meets the heat break and is set away from the heat block?
https://help.prusa3d.com/en/article/changing-replacing-the-nozzle-mini_134235/
Regards
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE: Blobs/Overextrusion with Prusament PETG
Yes i did. Its a prusa nozzle but this issue was the same issue ive had even before changing the nozzle also
RE: Blobs/Overextrusion with Prusament PETG
Does your nozzle look like the one on the right?
Cheers
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit
RE: Blobs/Overextrusion with Prusament PETG
Yes it does