MMU3 Jamming with filament unloading
Hi,
I am recently seeing an issue where my MMU3 is unloading filament and retracting it too far.. It would normally retract just behind the steppe driven selector and sit in the PTFE tube.. It is now retracting to the feed wheel and curling up and jamming when it tries to reload the filament.. this is now happening for multiple filaments, so not just a material issue or channel issue..
Is there some new firmware bug? or a way to calibrate the MMU3 so it won't unload so far, causing these jams? To fix, I have to pull out filament from the front, cut off the curled up piece, then pull back on filament from the back and refeed it into the middle section.
RE: MMU3 Jamming with filament unloading
Tried to access FINDA calibration based on QR code from error.. but my MK4S menu does no have the menu tree shown on the website:
LCD Menu -> Support -> Sensor info -> FINDA
I could not find the FINDA calibration option.. but confirm visually that the sensor ball is definitely rising when the filament passes through the carrier unit.
RE:
Newer versions of the FINDA sensor have a LED indicator, making it quite easy. If not, you can enable sensor status in the footer of the display, which is a bit sluggish but otherwise gives the same information. Make small adjustments by rotating it in its thread after slightly loosening the screw (short of twisting the cable, of course).
Try to set it halfway between "detects filament at the lightest touch" and "stops detecting filament". Otherwise it may become vibration sensitive if set to "just work" without sufficient margins either way.
RE: MMU3 Jamming with filament unloading
I ordered a new FINDA sensor to help tune.. Can you advise if there is any calibration option in the GUI to help identify the sweet spot? or do I just have to keep trying to feed the filament and let it crash? It is cumbersome to fish the filament back from behind the idler to the selector section.
Thanks, Appreciate your help.
RE: MMU3 Jamming with filament unloading
And is it such a problem to adjust it with a piece of filament from the front without a bowdwen? First, I need to find the FINDA position when it stops responding to the inserted filament, meaning it is too high. I mark the position on the FINDA body with a thin marker. Then I look for the position when FINDA reports that the filament is inserted even though it is not there in reality, meaning it is too low. I mark the position again on the body. And the correct FINDA position is somewhere between these marks. I set it to half the distance between the marks and try inserting and removing the filament and rotating it in different ways. I can change the FINDA position in small limits until the signaling works safely and then I carefully secure FINDA with a screw. And if FINDA does not have a red LED on it (although I have not seen such a probe yet), you can set the monitoring on the bottom line of the display. A matter for 10 minutes.