Been using prusaslicers default PLA profile with issues and this is my first roll of PETG, so I just selected the corresponding profile for that.
It seems so be super stringy whenever there’s movement and when printing the bunny (in vase mode) there’s lots of holes in the model.
I’m not sure if this is an issue with calibration (didn’t do anything when switching from PLA) or if the filament is wet.
Check for a partial clog. 80% of the time i get that consistency with petg, its because the nozzle is partially clogged. The other 20% is the ptfe tubing is shot. Usually it partially melts and causes underextrusion.
Wet filament could be an issue too, but this is pretty extreme for wet filament.
I found petg to be a lot more challenging to print with than pla, but there’s a lot of really cool benefits to using petg like it’s more permanent and more flexible.
I think the first thing to look at would be raising the temperature of your extruder. Seems like it isn’t really flowing a lot.
Do a temp tower. Find one hottest to coolest (260 to 220) and see where the sweet spot is. Going coolest to hottest could cause clogging.
And when in doubt make sure you PETG is dry. Likes to pull in the moisture. Tell-a-tale is popping and hissing.
Others: correct if I’m wrong but black PETG tends to be on the warmer side then other colours?
In my experience, moisture will cause excessive stringing in PETG long before it is saturated enough for popping/hissing.
I did two temp towers: 260-225
And
280-235
Although my printer didn’t want to go above 260, so the first layers are all 260.Yikes! Are you sure you sliced the temp tower for PETG profile? (as others have inquired)
I selected PETG filament profile in prusaslicer.
I wrote the custom layer change temp code to switch temps and checked in prusaslicer that temp changes occur the right places. (Using the color preview thing)
While printing I also saw that the temp did change where it should.
I think I’ll do a calibration of the feeding, or whatever you call it, where you measure how much filament is extruded. During some of the bridging, it looked like nothing got extruded.
It almost looks like 260 is the best temp. While extruding at this temp, I did heat lots of popping noise, which makes me believe the filament is wet. The noise did not occur at lower temps.
Kinda annoying when it’s a brand new roll.
You sure you are using the PETG preset? The only time my PETG prints have looked like that is if I accidentally use the PLA preset and it under-extrudes because the temperatures aren’t high enough.
Yup, looks like way too low temps for me as well.
That’s literally the first thing I thought of as well. A few times that I’ve mistakenly tried printing with a PLA profile while PETG was in the printer. Doesn’t get hot enough and really struggles to push the material through (for obvious reasons).
My vote is a combo but it includes being wet, is this a new roll or if not how did you have it stored? I have found PETG to be much more finicky with moisture than PLA overall so if you have a way to dry it definitely try that and see what happens before trying to calibrate it.
Brand new roll. I unfortunately don’t have any way to dry it :(
You can use your heated bed, just set a temp and cover the roll with a box.
https://3dprinterly.com/how-to-dry-filament-like-a-pro-pla-abs-petg-nylon-tpu/ Scroll down to the heated bed portion
I would try what that other person said, that’s a great idea!
Anecdotally, I actually just got through half of a brand new roll today that I opened two days ago and it has been printing from a dry box and it started spattering from trapped moisture (you will find little chunks of plastic on your bed in past experience) so it’s in the dryer now haha.
Hope it works out!
ETA: I live in CO, USA and the humidity in the room where the printer is currently reads 70.4F/50% and the dry box reads 12% for reference, not much for it to soak up from the air.
Double-check the print temperature, PETG should be about 240-ish. Also the spiral vase mode may be the issue if your model isn’t designed for it. Also check your z offset, the first layer should be almost a flawless sheet… if not, stop the print and try again while live adjusting the z until it’s correct. Typically PETG doesn’t like to be squished down as much as PLA.
