I’ve got an AMS on a P1s that started having issues feeding filaments. It makes it to the extruder than fails to load and backs up. So, first thought was bad extruder, so I replaced the extruder. No joy, next thought bad Filament Buffer, so I replaced the it. No Joy. I noticed the PTFE tube from the AMS to the Filament Buffer was a bit wonky looking, so I replaced it. No joy. By working backwards from the toolhead I’ve become pretty confident the issue is inside the AMS itself. My question is, what’s my next step? Should I try the mainboard, the internal hub? The PTFE tubes inside the AMS unit all appear fine so I’m thinking they’re not the issue. I should also point out, it’s happening from all 4 slots, so I’m pretty confident it’s not the feeders, unless all 4 went bad at exactly the same time.
Did you try taking the PTFE out of the toolhead and running a print? Keep your finger on the on/off switch because if the problem is in the toolhead it’s going to keep feeding and make a mess. If it keeps feeding it might be the filament sensor in the toolhead.
Also check the firmware version on just the AMS and see if it’s the latest.
I switched the AMS onto a different printer, the printer it was previously on worked just fine with the other AMS, the 2nd printer which had previously been working fine had the exact same issue with this AMS installed. I’ve opened a ticket, but we know how long that takes, if anyone has any suggestions I’d really appreciate it!
Isn’t the filament sensor on the toolhead? If so, that would be ruled out when I switched the unit to a different machine and it didn’t work and the “broken” machine worked fine with a different AMS on it. Or is there another sensor somewhere in the AMS?
I get the thinking, but the filament is really stopping before the extruder. If the extruder is the culprit then it would have a small piece stuck or a jam there from heat creep. Taking it apart and looking would be the first step. You replaced it so let’s move on…
Hardly ever the issue. Worst case the spring has gotten something in it. Nice thought though.
Could be, but maybe not how you think. The PTFE tubes are considered consumables. When the inner diameter get’s worn it causes pull back issues as well as other anomalies. Before tearing it down look at the run coming out of the AMS. Is the ID worn? if so you’ll see it, and if you see it you need to replace all PTFE. This will mean you have to take the AMS apart as well as replacing the run. If that PTFE isn’t worn, and it’s as old as the AMS, then move on.
Here would be where I’d look at the filament sensor. It’s on top of the extruder, it’s the part you push down on to remove the PTFE tube from the extruder. I would bet that’s the problem, especially after seeing you’ve looked at the PTFE in the AMS and it’s happening on all 4.
EDIT: I don’t buy that it’s not the filament sensor, even though you tried it on another printer. I have my reasons.
There is only one thing in the AMS that would affect all 4 feeders and that’s the hub inside the AMS. If the gear has lost teeth. The other thing would be all the tubes cut too long or worn, but you said you checked those. The motor being bad would not send any filament at all down to the head.
Since I have gone this far, you can look at the extruder wheel in the AMS for debris.
Internal hub got here, got it installed, and it appears to be working again. Going to run a few more tests with lots of filament changes just to make sure, but looks like the internal hub was the issue.