PETG bought at Prusa
Hi I recently bought this PETG roll of filament, I have printed loads of PETG before just started out on this new roll. I usually use the Prusament PETG profile for printing PETG and it works fine for every other random roll of PETG. However this seems like it might not like the 230 degrees temperature. It almost looks burnt. It does say 220-240 degrees on the roll. Not really sure if I should go higher or lower.
Have anybody seen this before?
Best Answer by Tinkerwest:
I have seen something like this on my printer you might want to check. My nozzle was not properly installed and it would randomly drip filament out the side between the heat block and nozzle. This would leave burnt spots similar to what your seeing and was most visible light color filament. I found cleaning the nozzle hot with a Q-tip before printing each time help before I was ready to do a full tear down and fix the problem. Hope this helps and good luck.
RE: PETG bought at Prusa
I assume those burned blobs build up on the nozzle because of a slight over extrusion.
RE: PETG bought at Prusa
@lichtjaeger
Interesting, but I am running standard settings, and I've just changed to another spool, which so far is printing beautifully, with the same gcode. But let's see if it finish the print.
I believe there might be something wrong with the spool, maybe impurities in the filament.
RE: PETG bought at Prusa
If the filament diameter on this spool is oversized, you will get the mentioned over extrusion.
RE: PETG bought at Prusa
@monotovarisj
"maybe impurities in the filament" could high moisture content cause this?
RE: PETG bought at Prusa
I have seen something like this on my printer you might want to check. My nozzle was not properly installed and it would randomly drip filament out the side between the heat block and nozzle. This would leave burnt spots similar to what your seeing and was most visible light color filament. I found cleaning the nozzle hot with a Q-tip before printing each time help before I was ready to do a full tear down and fix the problem. Hope this helps and good luck.
RE: PETG bought at Prusa
@john-k7
Ah john, this was exactly it, I noticed melted filament coming out of the side of the hotend, i just had it completely disassembled to clear a clock in the small threaded pipi between the cooling block and the heatblock. Something must not be alligned right.
I better take it apart and reassemble. Is there a prusa guide for correct assembling the hotend assembly?
RE: PETG bought at Prusa
@monotovarisj
There is several helpful guides for this, one thing to remember is that when you assemble the hotend, the nozzle once properly screwed in must have a gap between the top of the nozzle and the heaterblock (see picture in first link below).
So when nozzle is fully screwed it it must not stop against the heater block, it must stop inside the heater block against the heatbreak so you don't get any leaks (nozzle and heatbreak touching each other inside the heater block)
This is why the guide asks you to when assembling it for the first time (when heatbreak is not yet in the heater block) to screw in nozzle the unscrew it a bit.
some links:
https://help.prusa3d.com/en/article/changing-or-replacing-the-nozzle_2069#how-to-change-or-replace-the-nozzle
and this one:
https://help.prusa3d.com/en/article/hotend-disassembly-heatbreak-stuck-in-the-heatsink_112677
First link to e3d is helpfull too
RE: PETG bought at Prusa
@torbjorn-j3
Yes this was probably my mistake, couldn't find a guide when I did it, so relied on a mk3 youtube video, that doesn't explain it well.
Proper guide has been found now.