Problems with Filament Load
I am wondering if someone can provide any assistance or has come across this problem.
I normally do not have any problems with my MMU2, however in the last 2 months I have had several prints fail a different points. The problem is caused when part way through a print the printer moves the print head to the front right corner of the print bed and then the screen asks to remove the old filament and insert new filament. All I do at this step is press the Orange button and the MMU loads the filament and it starts to come out of the nozzle. After some has extruded the screen asks if the colour has changed. When you select Yes it then returns to the pruge block, but it lays down a very thick first line which causes the print head to hit this line on the next pass and register that it has a collision. When resuming from the collision the print is offset by 1-2mm and the print is destroyed.
I can concerned why the print is asking for a filament change. This process is almost identical to running a M600 gcode, however no such thing exists in the gcode file.
Has anyone had this problem or know of any fixes?
This just started happening to me too.
For large single-color prints, I now turn off the Filament Sensor to avoid this.
A couple months ago, I printed 6 dryboxes (~30hrs each) without issues. Since the firmware update, I couldn't print 1 without this failure unless I turn off the sensor. I'm using the same black PLA+.
I think (touch wood) that I have solved the problem. It appears my Filament sensor on the MMU2 was a little too high. I had recently disassembled it and when I put it back together I seated the FINDA against some filament and then moved it up 2 clicks. This was apparently too high and the MMU was thinking the filament had run out.
To fix it I put some filament in the MMU and lowered the FINDA and ball until it was touching (lightly) and then tightened everything in place. I just finished a 26 hour print with 940 tool changes and it only had 2 problems which were unloads but did not do the problem before where is asked to change filament. Perhaps try moving the FINDA position? (i didn't adjust the IR sensor as that did not appear to be causing any problems. Then again this might have just been lucky and the problem might return again!