I’ve had the printer for a few months, but have yet to use the right extruder. Went to use it for a multi color build, however it keeps failing to load filament to that right extruder. The AMS 2 Pro gets the filament all the way to the head and it instantly retracts it back. I can’t tell with 100% certainty, but it sure looks like the drive wheel instantly goes counter clockwise instead of clockwise to grab the filament and drive it into the hot end. It makes 3 or 4 attempts and then it errors out.
I took the unit apart and there is nothing jammed in there. And if I go into the manual control mode and tell the extruder to heat up to PLA temps, and then i use the down arrow to drive the filament through, it works just fine.
I miss some steps like verifying if the way of the filament is really free. It could be a bump somewhere in the line between the end of the ptfe and where it joints to the printhead.
Filament’s heads are clean, trimmed with scissors, not pointy or damaged by improper extraction etc
Hi, I’m replying because I know your pain. This issue happened to multiple people and there are other posts here that explain how they’ve fixed it (when you search, don’t search only for one of the extruders, it can happen to both).
The take aways are like this:
it can be the filament buffer(both if it gets stuck at the entrance of the filament buffer, or if it retracts too fast).
it can be something related to the extruder (like a clog inside the Dual Extruder Idlers and Filament Sensor or issues with the sensors)
For “easy” debug, just use the external spool to load filament on the one with problems, if it works like that then it might be an issue with the filament buffer. I’m currently experiencing the same issue and I’ve already reassembled the filament buffer multiple times. I think it’s something wrong with mine(since the first day I might add, when I kept getting errors on the same extruder for big friction whatever) and I’m waiting for its replacement, thus I cannot 100% confirm this, but others said they’ve got it fixed after replacing it.
I had a loading problem that could not figure out. It just wouldn’t load no matter what I tried. I ended up pulling the tube from the print head and forced the filament in and replaced the tube. No problems after that. I think the cut on the end of the filament wasn’t clean and it was catching inside the print head. I have taken more care to ensure the cuts on my filament are completely blunt and not pinched. No more troubles.
Hi, back with a confirmation. My ordered filament buffer arrived (it comes with cable and its board included) and after I’ve replaced it everything is perfect. The filament loads without issues and I’ve also observed that there is no more banding/visible lines over my prints in speed changes (or at least not like before).
At this point Bambu has sent a filament buffer unit, filament sensor assembly and a complete extruder drive assembly and i’m still having issues of being unable to load filament from the AMS 2 Pro units.