I3Mk3S + MMu2s does want to change Filament at print even right after power on
Hi,
Sorry for the bit bumpy title but I did not know how to express this any better. Let me explain the issue.
I am running this set up off printer and MMU for 1 1/2 years now successfully without any major issues
Recently I am experiencing a significant increase of the following behaviour, which I thought I would have an answer for it already, but now I must admit, the printer sometimes does some irreproducible things at print start.
The the set up respectively the situation:
NO Colour change is sliced, I simply use one spoon of filament e.g. sitting on extruder number 3.
I switch on printer and MMU.
i manually make sure, the MMU knows that the filament is loaded into MMU, by positioning the extruder via the MMU buttons and as well load the filament ( Just MMU, NOT to NOZZLE) using the centre button on the MMU.
I then start the print from the SD.
printer starts calibration, returns to the home position, and then moves the print head to the right with Y-axias position close to 0 and starts the reverse retract at the print head. NOTE: No Filament has been loadad to the nozzle so far. It still only is in MMUS Bondtech gears and SFINDA LED is red => no Filement in Selector Head.
LDC Dialog the says kind of: "Press button to unload old filament and to load new filament" ( which - see above - in that moment is nonsense).
As a result, the film and then is loaded from you, through Bowden into the print head without the MMU selector has changed its position.
Next is, that some filament is extruded down to the print bed and the LCD presents the question, if this is now the correct filament and asks for pressing okay button so to say.
Pressing okay does make the extruder to spill out another portion of filament and then to move to the home position and start the calibration again - which is super senseless, as it already has happened and the filament does reside in the bondtech gears and the nozzle already.
In the meantime the text appears in the display, that MMU requires attention and then changes to resuming and nothing needs to be done.
After calibration, the printhead again moves to the home position and wants to again load filament ( which it didi before and which now resides in the nozzle) and therefore some awful scratching noises do come both from the printhead and the MMU.
==> minimum issue ( if not more ) is that the printer "forgets" that is was loading the filement right before the second go of calibration.
The gcode does NOT show another "T" command - and as I did power on the printer just before that, the printer or MMU should not think it needs to change filemanet.
The same sometomes happens when reprinting the same model with the same filament.
Any ideas what this is ? Any fixes?
For a while I thought it might happen when re-using 3MF files, but thisoccurs as well sometimes ( irreproducible ) even when creating a fresh 3mf and ensuring to only use ORIGINAL configurations.
help is appreciated ... and .. yes it is the most recent FW, which was valid till some days ago and fw 3.11 DOES NOT TELL the'd have fixed an issue comparable to what i experience.
A few seconds later this stops, and the print starts.
RE: I3Mk3S + MMu2s does want to change Filament at print even right after power on
LDC Dialog the says kind of: "Press button to unload old filament and to load new filament" ( which - see above - in that moment is nonsense).
As a result, the film and then is loaded from you, through Bowden into the print head without the MMU selector has changed its position.Next is, that some filament is extruded down to the print bed and the LCD presents the question, if this is now the correct filament and asks for pressing okay button so to say.
Pressing okay does make the extruder to spill out another portion of filament and then to move to the home position and start the calibration again - which is super senseless, as it already has happened and the filament does reside in the bondtech gears and the nozzle already.
In the meantime the text appears in the display, that MMU requires attention and then changes to resuming and nothing needs to be done.
Hello,
I recently had a similar problem with intermittent message like this one. The MMU2S believed it ran out of filament. I had to remove the FINDA sensor and the ball and then remove (blow out) some bits of filament. Then put the ball back in, recalibrate the FINDA sensor by sticking filament in and out : https://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250.
Once I made sure the FINDA was reliable, the MMU2S stopped thinking it ran out of filament.