MFM recurring error

infiniteloop

@wouldstain said in MFM recurring error:

I think an injection molded case would remove any uncertainty around it but I'm not certain that would resolve this issue.

My MFM works reliably, the electronics are pretty well engineered. The - self-printed - case needed heavy postprocessing, I had to file, drill, cut and sand a lot. Especially the filament path and the idler are problematic, the often mentioned distance between magnet and sensor is no theme anymore since introduction of the 2 mm magnet in v2. So yes, an injection molded case would be helpful.

Given the high precision of detected filament movement, a direct coupling with the extruder - or better, an integrated design - is still on my wish list …

But, again: if the magnet rotates as intended, PCB and I2C transmission work flawlessly. @dc42 has made a remarkable job to ensure reliability of the data, so, as long as we get our cables right, we won't run into problems on this side. Simply put: it's the mechanics we have to take care of.

wouldstain

@infiniteloop No doubt! I'm still pretty new at this and I generally assume it's something I'm doing. Given what you're saying about post processing and my questionable print quality, I would not be surprised if there are tolerance issues with my casing.

wouldstain

@phaedrux
Finally got around to reprinting case. Used PLA this time instead of PETG.
It's alot cleaner on the outside but really no difference on the inside.
I ran a needle file through the feed path just to be certain there's no blobs or burrs

Initial reading (before printing first time). As you can see, AGC has gone up quite a bit.

Duet3D rotating magnet filament monitor v3 on pin e0stop, enabled, sensitivity 28.80mm/rev, allow 60% to 160%, check printing moves every 3.0mm, version 3, mag 133 agc 111, no calibration data

1st test / calibration print on 20mm calibration cube:

35% ona "too little movement error":

Duet3D rotating magnet filament monitor v3 on pin e0stop, enabled, sensitivity 28.80mm/rev, allow 60% to 160%, check printing moves every 3.0mm, version 3, mag 132 agc 109, measured sensitivity 25.84mm/rev, min 35% max 106% over 983.4mm

adjusted M591 while paused to:
M591 P3 C"e0_stop" S1 D0 L25.84 R35:130

Print completed without further error.

2nd test completed without error.

3rd test printed 2 x 20mm calibration cubes simultaneously

Stopped at 88% with the following:

M591 d0
Duet3D rotating magnet filament monitor v3 on pin e0stop, enabled, sensitivity 25.84mm/rev, allow 35% to 130%, check printing moves every 3.0mm, version 3, mag 132 agc 109, measured sensitivity 26.05mm/rev, min 0% max 109% over 2811.8mm

So... Even with the new case, it's still randomly stopping.

I'm thinking there's a problem with the MFM.

Phaedrux

Please send an email to warranty@duet3d.com and CC your reseller. Include a link to this forum thread and the details of your original purchase. You'll receive a reply with a form to fill out.

wouldstain

@phaedrux done. thank you!