Hopefully this makes sense, I’ve noticed this on both my AMS and AMS 2 Pro.
When you are finishing the last of a roll of filament, and it pulls the last bit off of the roll, and past the AMS filament hub, the printer is smart enough to know that it can rewind what little is left on the roll. It proceeds to poop of the last bit of filament that is in the tubes.
Perfect.
What i’ve noticed 2 times now, is it sounds like the AMS hub in the bottom continues to spin or work, making noise. This motor shouldn’t be making noise if the filament has been pull all the way through and completed the purging of the last bit of filament.
It’s easy to replicate: have a print finish with enough filament to still be in the tubes/buffer etc, and let it purge out the last of that filament until the run out sensor in the extruder detects its the end of the filament. You’ll notice your AMS Hub motor still making some sounds.
I just experienced exactly this with my P1S + AMS. When I saw the print was going to finish with the last bit of filament between the buffer and the printer’s intake, I wondered if I was going to have to disconnect the PTFE tube and manually pull the last bit out. But the printer purged it. That’s well and good, but it wasn’t until a few minutes later I realized I was still hearing a motor running - the AMS, trying to rewind nonexistent filament.
I ended up power cycling the printer. I don’t know if the AMS would have given up eventually, or if it would have spun for hours and burned out the motor. But this seems like a firmware bug. The AMS knows when I stick a piece of filament in, so it should know when it’s run out and there’s nothing to rewind.
Just had this exact thing on my P1S. It purged the last of the filament out but the AMS hasn’t got the message. Power cycle is the only cure apparently.
i have submitted a support ticket. not much success. they tell me the AMS filament feeder may be damaged, or need cleaned. I doubt it, this happens on my NEW AMS PRO 2. it is a certain sequence that does it.
SO, here is a possible test, if you want to test this, and i may do this in some free time. RECORD the results, and send them to support
create a small test block that uses about 1 gram of filament.
cut a strand of filament of about 5 g, so it can feed into the ptfe tube, etc (simulates a roll being present, feed it into the AMS)
start the print job, and once the printer starts printing, CUT the filament at the AMS insertion point.
now the AMS will say to itself “the roll is empty”. the printer will print the test cube, then purge the remaining filament. THEN see what the motor does.
maybe we can narrow this down or get support to look at it
its like talking to the wall…. initial replies are robotic,i guess, just pick the closest thing available and spew it out to customer.
i this issue has existed for couple years. I KNOW it happened, i observed it, but then i’d just reset the machine and got the motor to turn off, but last week it bugged me enough to look on line here, found this thread, and figured i’d write to support.
SO, if they test it as i indicated above, that should reproduce it.
if I CAN FIND some time to test this, i will do so . I have a small test cube that i print, i use it to print filament, AFTER i remove the TPU that i printed, so that the tpu is cleared from nozzle.
I can use that for test, start the test, cut the filament strand that is going into the AMS, once the printing starts (the part that is then in the PTFE tube is enough to finish my test cube),and then the motr will probably continue to run. BUT THEY CAN DO THE SAME TEST !!! THEY make the machine !! you think they’d want to investigate this, especially after several users (that’s just the users who posted here) experienced this…
I did my sequence. I started my test cube, and cut the filament at the AMS inlet. so, immediately after starting, the filament feeder motor light turned to red (filament roll was “out”. the cube printed. the filament tail exited the AMS, and the motor ran - for about 15 seconds !! it then SHUT OFF !!! It made a FOOL of me. I KNOW the motor stayed on, two days ago, when the ROLL of filament got finished, before end of print project, but enough filament in the PTFE to finish project, and teh AMS motor kept running at that point, even after purging of filament form PTFE, until i turned the machine off. WHAT is the difference if i CUT the filament, to stimulate “END-OF-ROLL”, versus it running out by itself?
if anyone else can test this, and see if we can see exact sequence of what does this? is it the TAIL of filament on the roll, with the BEND in it, that causes something? I don’t think that is it, because i’ve CUT that tail end, at other times, when a project was almost done, and motor kept running….
I am at a loss !!
nOTE, here is my test cube, if anybody wants something simple to test with - uses 1 gm of filament. i have it set for PETG so that when i print tpu, and then run this through after, it is at higher temperature than teh tpu. but for purposes of this thread, it does not matter