I had a spool of Bambu orange filament snag in the AMS. Later I printed white PETG and had to abort because it was full of black specks.
I tore down my extruder and cleaned all the black debris out of the yellow gear and blew the whole thing with a high powered electric blower.
I did a cold pull to make sure nothing was in the nozzle and it came out perfectly white.
Then I tried printing white again and got this. What else do I need to do?
I had some stuff that the same problem and spent about 10 seconds thinking about it then forgot and moved on, so Im interested in this also, I wonder if the ptfe tubes may have some debris floating around in them. I also saw in another thread where there was lots of stuff in the AMS hub.
When the orange filament retracted it was covered in black specks all along the length that was in the system.
That sort of contamination is not typical of a fouled extruder but rather a nozzle that has accumulated other filament. I used to see this much more frequently when mixing filaments of widely different temperatures. So as an example, if I ran PETG at 250 C that was black and then tried to run PLA that was white at 210 C, the residue from the PETG did not always purge.
There are several methods one can use, the simplest is to run the nozzle at a temp 10C higher than your previous hottest filament. Then pass through a length of the filament you intend to use until it runs clean. Think of it as a super-purge.
You can also try a cleaning filament although the one I used is still half unused because to be honest, I could not see a difference when I used it compared to the method I mentioned above.
Personally I found very little value in these products but they may be worth a try.
https://www.amazon.com/s?k=3d+cleaning+filament
This was the material I purchased in 2023. It was ineffective. It has since been taken down by Amazon:
Bambu gave me samples of that with my printers but I never used it.
I printed a 50x50 cube in white PETG. It started out with black specks then cleaned up.
I’ve never printed black PETG so I don’t know what the particles were. I’ve printed several white parts today with no problem.
When this happened on my A1 it turned out to be the silicone sock deteriorating. But I checked my P1S sock and there’s no issue.
3 things:
exterior nozzle/sock - use a brass brush and brushy the hot nozzle every now and then, gets everything off real well, won’t burn yourself
ptfe line - Sometimes the AMS motor gear will chew a piece of filament when you get a stuck nozzle, and that chew confetti stays in your PTFE till you clean it out. disconnect + air, possibly disassembly to deep clean the ams hub
interior - Cold pull IMO
I’ve found certain rolls leave burnt crud in the nozzle, caked onto the walls, that really only cold pull reliably gets out. Elegoo PLA+ White and Pink tend to do it to me. Among others.
Disconnect the PTFE tube at the hotend and use your electric blower to blow out the tube, you could easily have little bits of darker material in the tube that the filament is picking up as it travels down the tube.
Will do! Any reason to use that mini-vac / blower. I cleaned out the extruder but didn’t consider the area above it.
