Best posts made by wouldstain

@deckingman

Possible solve...
I may be speaking too early on this but it's looking promising.

I've been super focused on what could cause the filament to start a phase transition
in the wrong location and I THINK I've got it.

The short of it is that the PTFE tube connecting the extruder to the hotend may have been a hair or two short of seating solidly against the heatbreak.

Long version...
The way this probably came about is, because the PTFE collet on the bottom of the extruder is not visible from above (I have a Railcore 300ZLT so it's pretty tall and sits on the floor), I'd gotten in the habit of leaving the collet on the extruder and removing the one on the heatsink coupler and just pulling the extruder and tube out in a single step. When reassembling the extruder after cleaning it, I probably seated the tubing as far into the extruder as I could, leaving a small gap between the heat break and PTFE tube. Clearly I must have cut the tube a bit short.

This was literally the only thing I could of, so I tried re-seating the tube all the way down inside the heatsink, reassembling everything, and I'm suddenly able to complete a test cube out of PLA.

Going to run a few more tests before I call this one resolved but this sort of fits what I've been seeing and is consistent with your advice about what could cause this.

Found good info on troubleshooting E3D v6 problems here.

@t3p3tony It's looking like the PTFE tube was in fact the issue. I've successfully printed out a few items in PLA now with zero stops. I've also dialed back the MFM parameters so it's no longer wide open and still no problems.

I have to pull the tube out and measure it to see just how short it was (build docs call for 91mm) but the only things I can attribute this to is my being a creature of habit. I've pulled that tube many times while yanking the extruder for cleaning and repeated the same error by installing it in the extruder first.

I'd say mark this one as resolved but I'm going to run some longer prints in PLA just to be 100% as there was an element of randomness to it.

Props to @deckingman for getting me focused on the right thing and thanks to everyone who responded!

@t3p3tony

MegaBot_Sitting_Body_Upper.gcode

@fcwilt Ive tried several brands of PLA, all with the same result.

@dc42 attached as requested.

config.g

@fcwilt had same issue w/ 3.3

@t3p3tony
Console output:

1635171097795-mfm-test-1:
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 131 agc 75, measured sensitivity 25.89mm/rev, min 99% max 103% over 48.1mm

1635171097802-mfm-test-2:
Duet3D rotating magnet filament monitor v3 on pin e0stop, enabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 132 agc 77, measured sensitivity 26.00mm/rev, min 95% max 102% over 99.6mm

1635171097805-mfm-test-3:
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 132 agc 75, measured sensitivity 25.87mm/rev, min 98% max 102% over 49.0mm

1635173702760-mfm-test-4:
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 132 agc 75, measured sensitivity 26.09mm/rev, min 97% max 102% over 39.1mm

1635178672431-mfm-test-5
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 131 agc 75, measured sensitivity 25.88mm/rev, min 98% max 102% over 99.3mm

1635178672433-mfm-test-6
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 131 agc 75, measured sensitivity 25.99mm/rev, min 97% max 104% over 99.4mm

1635178672436-mfm-test-7
Duet3D rotating magnet filament monitor v3 on pin e0stop, disabled, sensitivity 26.50mm/rev, allow 1% to 200%, check every 3.0mm, version 3, mag 131 agc 75, measured sensitivity 25.79mm/rev, min 98% max 101% over 45.4mm