I’ve searched around and don’t see this particular behavior mentioned. From every slot, on every print, as soon as the warmup steps are done, I immediately get the error “failed to send out filament.”
What is baffling is two-fold:
It doesn’t even try. There are not even any sounds indicated an attempt to move anything. It just instantly pops up the error message.
I can load and unload filaments from the AMS as normal, including the little “test feed” that it does, which feeds filament through with no issue.
Full disclosure: I almost definitely caused this, as this began after some super-hacky experiments that broke off a piece of filament along the path more than once. BUT it sure seems like everything is clear, and now I’m at a loss for how to proceed, since the AMS doesn’t even attempt to send the filament out from any slot. This seems like a “turn it off and back on again” kinda thing, but I’ve done that more than once and it doesn’t seem to matter.
Unfortunately it means opening it up again but I had it happen when about 1cm of filament broke off down where the 4 PTFE tubes come together at the bottom of the AMS unit in the path of the filament detector. I think that’s why it just reports the error before trying anything.
I opened that 4 to 1 thing to find the filament. You may be able to just use a piece of filament to push the short bit out without opening the mechanism. I didn’t try that. Be careful of tiny parts if you open and see the bambu wiki.
Thanks for responding so quickly with a specific potential remedy!
Bambu seems to call it an Internal Hub Unit, and starting from here will provide information about how to get inside it:
Unfortunately, I did not find anything in there, and the behavior remains.
I am able to manually feed filament through all 4 paths with no issues, so I’m increasingly convinced something electronic has failed. Time to learn how to file a support ticket, I guess!
Oh, well that stinks. Don’t forget to check the extruder too. There is a sensor there as well and I think a broken piece there may do the same thing.
It’s easy to press the ring and pull the PTFE tube to look down. I had a piece there too keeping me from printing when I had brittle filament decide to do that.
Takes fine tweezers to get to it but a filament piece with something sticky would probably grab it in a pinch. It was sitting there loose in mine.
Another great thought! But I can’t find anything in there.
Upon further reflection, I think the culprit has to be in the AMS, because I am able to print just fine from an external spool. (Actually printing as I’m typing this!)
I have filed a support ticket, but please keep suggestions coming. Would love to close that!
Turns out the Filament Buffer crapped out. Tech Support sent me a new one and I seem to be back in business!
YAY!
Very good customer service, but I do have a suggestion for the printer firmware in the future: Detect this situation and report it both directly (i.e. say “no signal from filament buffer”) and immediately (not after 6 minutes of various warmup tasks).
Anyhow, time to get back to my backlog of crazy multi-color and multi-material R&D!