MMU2s does not realize it loaded successfully?!
Hi!
After jaming the extruder with PETG "fibers" my MK3s/MMU2s does not realize when the filment is successfully loaded:
It loads, leaves a big blob of molten plastic on the printbed while continuing to drive the extruder at high speed - clicking&bending the filament - and then reports a load failure.
I suspect a problem with the IR sensor at the extruder.
Any ideas how to debug this?
Any common things to check?
Thanks!
RE: MMU2s does not realize it loaded successfully?!
Fixed!
I took the time to connect the multimeter to the sensor and indeed it did not work!
The reason was that I loosened the screws while disassembling the printhead and that allowed the sensor to move a tiny bit to the left.
Since the tolerances are so minute it was enough to keep it from working.
Btw. the printer does not even recognize when the sensor is disconnected!
RE: MMU2s does not realize it loaded successfully?!
No, it doesn't check for sensors. 😉 But I used this feature to solder an indicator LED on it while having a print running...
RE: MMU2s does not realize it loaded successfully?!
I suddenly seem to be having a similar issue. MMU2S keeps advancing and withdrawing the filament after the extruder drive has already grabbed the filament and fed it into the hotend. It ends up in a tug-of-war between the extruder and the MMU2S.
Often this ends up in a pile or blob of filament under the extruder, otherwise it ends in a bunch of noise and shredded filament, before the printer pauses the process because of an MMU2 load error.
I've cleaned out the hotend, replaced the PTFE tube, checked the FINDA and adjusted the IR sensor a dozen times. No change.
Running the current (3.8.1/1.0.6) firmware.
RE: MMU2s does not realize it loaded successfully?!
Made another attempt. It appears that I am running out of adjustment for the IR sensor. I can force it over to the right just enough to get it to detect the filament, but it will be back out of adjustment by the time it needs to load filament.
I'm guessing the easiest solve is to print a new extruder door with a longer flag on it.
RE: MMU2s does not realize it loaded successfully?!
I suddenly seem to be having a similar issue. MMU2S keeps advancing and withdrawing the filament after the extruder drive has already grabbed the filament and fed it into the hotend. It ends up in a tug-of-war between the extruder and the MMU2S.
Often this ends up in a pile or blob of filament under the extruder, otherwise it ends in a bunch of noise and shredded filament, before the printer pauses the process because of an MMU2 load error.
I've cleaned out the hotend, replaced the PTFE tube, checked the FINDA and adjusted the IR sensor a dozen times. No change.
Running the current (3.8.1/1.0.6) firmware.
I am having the exact same error and it is driving me to dispair. Using the diagnostics on the readout where you can see the status of the sensors all looks okay.
Unfortunately you can onlu use the diagnostics either when printer is not in use (so check sensors by manually pushing some fillament past each sensor) or duriong a print. Would be really noce to be able to use it when pressing load filament to nozzle but you can't.
The sensors seem to work fine and really robust.
I have really carefully calibrated the sensors.
When starting a print the filament goes past the FINDA, but the diagnostics say it is a zero. However it is definitely made and so I suspect the readout only goes to a 1 when both are made for the first time as as soon as the filament IR sensor makes they both come on. After the dirst time the FINDA comes on just when the FINDA is made. Not sure what is going on there.
But the filaments only load ablut 1 in 5 times, the other times they continually load to nozzle then unload and finally faults out.
I can see absolutely nothing wrong and have spent over 8 hours on the help chat line sending photos, videos and they cannot help either.
Steve
RE: MMU2s does not realize it loaded successfully?!
@steve-t
I was finally able to figure out when I tried to do a First Layer Calibration. During the loading sequence I was able to bring up the status and see the IR sensor flicker from 0 to 1 to 0 when I could see that the filament had reached the extruder gears.
I did what was probably not advisable and adjusted the IR sensor holder during the load sequence for the calibration, and pushed it to the right (with some force it seemed) until it stayed steady.
I had to do this twice before I got the sensor far enough over to register every time it loads.
RE: MMU2s does not realize it loaded successfully?!
@steve-t
I was finally able to figure out when I tried to do a First Layer Calibration. During the loading sequence I was able to bring up the status and see the IR sensor flicker from 0 to 1 to 0 when I could see that the filament had reached the extruder gears.
I did what was probably not advisable and adjusted the IR sensor holder during the load sequence for the calibration, and pushed it to the right (with some force it seemed) until it stayed steady.
I had to do this twice before I got the sensor far enough over to register every time it loads.
@stephen-s27 I have looked and looked to see if I can see a flicker but it is rock steady. All I can think is that the panel is quite slow to update (if you watch the PINDA whilst doing the bed mesh levelling then it hardly ever goes to 1 due to speed it soes it) then maybe the IR goes off momentairily but you do not see it on the readout.
Steve
RE: MMU2s does not realize it loaded successfully?!
@steve-t
yep I am having the same problem (using the latest firmware as of 2 weeks ago)
RE: MMU2s does not realize it loaded successfully?!
i found my problem i had to ajust the filament sensor
RE: MMU2s does not realize it loaded successfully?!
I added a 5volt LED to mmy filament sensor, to make the filament status easy to see...
in the second picture, you can see the connections on a Mk3s with the cover missing, for Clarity!...
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: MMU2s does not realize it loaded successfully?!
I added a 5volt LED to mmy filament sensor, to make the filament status easy to see...
in the second picture, you can see the connections on a Mk3s with the cover missing, for Clarity!...
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: MMU2s does not realize it loaded successfully?!
@joantabb
Hi, Yes I too added a sm led similar to yours. THis also shows the filament is loaded absolutely fine but it gets rejected and retracts and tries to reload up to 3 times I think then fails.
RE: MMU2s does not realize it loaded successfully?!
@hkmortensen
Cheers but done all that and with my LED I know the filament has loaded and the sensor has seen it and does not flicker once loaded.