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Prusa Mini vs Prusa PETG Jet Black  

Active Member
Prusa Mini vs Prusa PETG Jet Black


anyone else having issues with Prusa PETG Jet black clogging their extrusion motor and gears as well as the nozzle on the Mini+? I've had this one roll that keeps being a nuisance, I've upped the temperature to 260°C on the (stainless steel) nozzle and it still seems to clog both hotend and the extruder ( although one might lead to the other). All other filaments print just fine, including Prusa PETG in other colors - which surprises me, because I was under the impression that PETG Jet black and PETG Prusa Orange were the easiest to print.

I've fitted a new heat break PTFE tube to make sure that this isn't the issue, swapped the nozzle in at 290°C, cold pulled it after every clog, needled the nozzle with a variety of acupuncture needles and the problem still persists but only with Jet Black.

While I could try another roll I have, I'm rather hesitant to do so because if this keeps being a problem, I'll just sell them to someone that has a direct drive printer or something that is more willing to just push through the issue.

Posted : 31/07/2023 11:06 am
Reputable Member
RE: Prusa Mini vs Prusa PETG Jet Black

same here, pieces of the filament are to brittle (they do not bend) other pieces of the same roll are too soft (and clog). I have no issues with other brands of filament...

Mini with FW:4.4.1 + SuperPINDA + Bondtech Heatbreak + PC4-M8 couplers + 1 piece boden

Posted : 31/07/2023 2:49 pm
Famed Member

I've printed dozens of spools of jet black PETG on my minis with no issues and standard Prusament settings but I also use Bondtech extruders, which I've found to be much more reliable than the stock extruder and the only upgrade I truly recommend. 

Posted : 31/07/2023 3:18 pm
Eminent Member
RE: Prusa Mini vs Prusa PETG Jet Black

Generally reasons are:

  1. to tight extruder screw
  2. ptfe tube
  3. not tighten nozzle.
  4. broken thermistor and nozzle is not getting hot enough. (You can measure it with multimeater)
  5. broken gear in extruder (you have to put this crap apart and do visual inspection)

If any of those are matching your problem then its time to modify your printer with bondtech extruder which works flawless  comparing to prusa garbage and revo to forget about ptfe/nozzle swapping problems 😉

mini+ [bondtech dual drive, revo, reprinted with PA11-CF and ASA] lives in photo tent.
mk4 stock (with some parts reprinted) lives in prusa enclosure.

Posted : 01/08/2023 9:57 am
Active Member
Topic starter answered:

1. experimented with that, I've loosened it somewhat but that doesn't seem to be the issue as I should be having issues with other filaments with this too
2. as I said, new one swapped in, no problems with other filaments
3. Nozzle swapped in and tightened with appropriate tools
4. Nozzle is definitely hot enough, swapped thermistor, block and heater cartridge recently.
5. extruder is still working fine
although, I am seeing a lot of black dust in the extruder whenever I take it apart.

As I said, the filament seems to be an issue because its the only part here that doesn't perform, everything else works as advertised.I've gone through multiple rolls of PETG from other manufacturers and even Prusa, none of them ever jammed my extruder or clogged the nozzle.

Posted : 01/08/2023 11:44 pm
Trusted Member
RE: Prusa Mini vs Prusa PETG Jet Black

The black dust is just a result of the extruder gear eating away at the filament when it encounters the resistance from the clog.

Have you dried the filament yet? If there's moisture, it could be expanding in the heatbreak prior to actually melting, essentially acting as a cork.

Is it clogging immediately when you load the filament, or does it only start while printing? (wondering if retractions are exacerbating the issue)

Posted : 16/09/2023 8:44 am
Hoof Hearted
Eminent Member
RE: Prusa Mini vs Prusa PETG Jet Black

I was having clogging issues last week. Changing the hotend ptfe tube fixed it for me. But you say you've already tried that.

Posted : 19/09/2023 6:33 pm
Active Member
Topic starter answered:
RE: Prusa Mini vs Prusa PETG Jet Black

nah, I get black dust from every filament.
Filament is dry.
It clogs at random moments in my experience, or during bridging.

Posted : 25/09/2023 2:52 pm