I’m trying to print petg, and I’m finding that the batch (3 different colors) that I have seem to be making crumbs of filament (see first pic to see what I mean), and forming a buildup of filament around the sides of the nozzle (second pic is the blob I pulled off the nozzle halfway through when I paused printing.) The print came out decently good. I was using a temp of 230, textured PEI plate set at 70, and I calibrated flow using OrcaStudio 1.5 (all of this PETG seems to under-extrude according to the calibration.)
I’ve been printing for a few years with a Prusa, and then with a Bambu since December, and I’ve never seen anything like this. Any suggestions? could it be wet filament? Over-extruded? fan setting wrong?
Crumbs, after I removed the print. These were basically spread out around the build plate like this.
Whenever I get a really weird things happening with a filament, especially when it breaks or snaps, my 1st go to is to dry it per the manufacturer’s suggested time and temp.
About 90% of the time that fixes it.
PETG in particular is very hydroscopic (loves water). Some are so hydroscopic they’ll take up enough water during a very long print to cause failure or major change in surface!
AMS owners - don’t forget that it takes some hours or overnight for the AMS to dry down after you’ve changed filaments, very easy to forget. Yes, it’s a ‘dry box’ but it’s only a little desiccant, not a heated dryer.
Most filaments don’t care but there are some that are ‘tetchy’ (touchy) to use a American deep south slang, like Nylon blends can get ‘wet’ in 2 hours!
EDIT: Meant to include this - a nice article on moisture and the different filament types susceptibility.
I think the filament was either Overture or Polymaker PETG, but I’m not certain. I did try putting it in my filament dryer (Sunlu brand) and I’m drying it again now. I also added 3 extra dry boxes to my AMS, and the hygrometer in the AMS (in one of those dry boxes) reports < 20% humidity.
I’m going to try to some experiments at higher temps to see if that helps.
Damp filament is such a PITA. There’s so many slicer profiles and settings, temps, beds, on and on that the simple thought that the plastic must be OK rarely is considered until like the 20th post …!
I’m lucky I have a high accuracy drier that is run in a dehumidified room and am fanatical about putting away my reels in dried storage.
Then I only have to worry about those 300 other factors.
I’m having a similar issue with the default settings for PETG at 0.12mm layer height. The default 0.2mm layer height settings have always seemed to work fine. This is the first time trying the finer layer height. I didn’t do anything special, just selected the different layer height preset, sliced it, and let it go.
My print had little plastic crumbs all over the bed at the end of the print. I was able to see the crumbs forming at the nozzle as it was printing. They would form just beside the nozzle tip, break off, and another would begin forming. At the end of the print, there is a blob of material on the nozzle.
I can provide photos if I figure out how. The forum says I cannot embed media files here… Perhaps because my account is too new.
I’m having the exact same issue. I’m using Overture’s Marble PETG.
It was so bad I couldn’t get a print out of it, but I turned the fan off, raised the temps to 250 and I can get a pretty good print.
Sadly though, the “dust” and buildup on the nozzle continues.
Sometimes it’ll form a ball and just roll it around for a while.
Hi nickt. I have a new P1S and am having the same issues with bambulab PETG. Can you please give me an update on how you solved the issue? Thanks, Albert
like Nylon blends can get ‘wet’ in 2 hours!
