I am printing PETG (Bambu and another company) at 255.
My problem aren’t the prints but the purge spaghetti When I print PLA, the purge temps go up to 250 and I get nicely melted balls of poop in the waste bucket. It goes to 280 for when I am printing ABS.
For PETG, it seems to want to drop the temp to 220 and that makes these long strands of spaghetti poop that don’t have the weight to fall out and end up staying stuck to the nozzle and pulled out onto the print bed, triggering the spaghetti detection. It isn’t making any sense. The worst of the two filaments in the Bambu PETG White, but I had similar behavior with the Bambu Purple PETG. PETG is the only material I’ve printed which has behaved this way.
I also noted that for PETG, it seems to do multiple purges for the same filament change, blue to white or white to blue, even though I have the numbers at 200 for each color. It doesn’t do this for ABS or PLA, so I figured it had to be somewhere in the Bambu Studio filament-specific settings.
I bumped up the minimum on one of the PETG to be 230, but it keep dropping to 220 to purge. I can’t seem to locate where else to adjust this for when it is doing filament changes. It seems counter-intuitive to drop the temp below the printing temp to purge the material versus increasing it.
What am I missing here?
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ive been battling this problem relentlessly with zero fixes. i get more errors stating that the chute is clogged than anything else. Heck, ive even had a couple of purges come out the chute as an insanely long strand…
I’ve tried everything i can think of. Checking flushing volumes, temp towers, filament calibrations, verifying that the filament is dry… nothing seems to help
At first I was going to suggest you that you check to see what your Max “Recommended nozzle temperature” is set to. This is what normally controls the flush temperature.
BUT then I checked the machine gcode and found this nugget.
Seems the flush temperature for PETG is hard coded in??? Very odd but changing this value should solve your issue.
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Wow! 
Shows how little I know about the printer and Bambu Studio! I didn’t even know they had that level of detail for the Printer/Nozzle hidden away like that.
Wonder why they would have hard-set something like that for PETG. Would seem odd to go that low when that is toward the low end for PETG, but they go to max temp on ABS, PLA, and TPU.
Thanks!
That fixed it. Bumped it to 240 and getting tight wads of poop instead of stringing.
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the hero we needed and the hero we deserved. next time i print with petg i am doing this. thanks for having the sense to check that.
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this seems like something Bambu should fix in the build. I’ve been using Bambu branded PETG and even at 240 it’s still producing spaghetti that clogs the purge chute. Will try pushing it higher or just removing that conditional next time I do a PETG print.
To circle back on this, the latest version of Bambu Studio has fixed this.
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I checked when I updated and they did fix it. It is now 260 by default.
