Really appreciate the thoughtful, detailed response, thank you! I've not had many issues with my various Duet products, but when I do this forum has always been incredibly helpful.

I will check the cable crimps for sure, great idea (I created the cable from the Duet wiring kit). The cable is not shielded, and it is zip-tied into the wire bundle, so your point about noise from the extruder motor cable is very plausible; I will separate it from the bundle on the next run and see if that eliminates the false alarms. Perhaps I should even try a shielded, pre-made cable to eliminate both possibilities.

Sounds like my setup is similar to yours...I created a custom mount to place the MFM just before the BMG extruder....eyeballing it it's probably ~50mm or less.

I do have a long bowden tube to get outside of a normally enclosed case, but it is almost entirely pre-extruder. Collet clips are in-place, and I did carefully cut (and re-cut, sigh) the short tubes between the MFM and extruder, and extruder to hot-end, so there is no obvious flex when the extruder is pushing. Here is my setup:

Thanks again for all the great tips, I will check all of these as well as increase the measurement distance a little further, and see if I can eliminate the false alarms.

Really appreciate the thoughtful, detailed response, thank you! I've not had many issues with my various Duet products, but when I do this forum has always been incredibly helpful.

I will check the cable crimps for sure, great idea (I created the cable from the Duet wiring kit). The cable is not shielded, and it is zip-tied into the wire bundle, so your point about noise from the extruder motor cable is very plausible; I will separate it from the bundle on the next run and see if that eliminates the false alarms. Perhaps I should even try a shielded, pre-made cable to eliminate both possibilities.

Sounds like my setup is similar to yours...I created a custom mount to place the MFM just before the BMG extruder....eyeballing it it's probably ~50mm or less.

I do have a long bowden tube to get outside of a normally enclosed case, but it is almost entirely pre-extruder. Collet clips are in-place, and I did carefully cut (and re-cut, sigh) the short tubes between the MFM and extruder, and extruder to hot-end, so there is no obvious flex when the extruder is pushing. Here is my setup:

Thanks again for all the great tips, I will check all of these as well as increase the measurement distance a little further, and see if I can eliminate the false alarms.

Good morning Duet collective,

I have read the other threads and have seen similar issues, but nothing that has resulted in consistency with the monitor.

I am having some calibration issues for the rotating magnetic sensor. My setup: New-ish Railcore printer, BMG extruder, v1.7a magnetic sensor board mounted right before it, black FDM self-printed case sanded down to achieve AGC of ~80-81. There is an approx 1m cable from the sensor back to a Duet Wifi v1.02 board, running firmware 2.05.1 per a previous recommendation.

My issue is inconsistent triggering of the stop actions.

I started with this somewhat generic but tuned config:

M591 D0
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 25.20mm/rev, allow 70% to 130%, check every 3.0mm, version 3, mag 130 agc 81, measured sensitivity 25.10mm/rev, min 96% max 105% over 446.9mm

In this configuration I get no more than 20-30 minutes of runtime before it bombs out with "Too little extrusion", "Too much extrusion", or "Sensor not reporting"...? When extruder gears are turning, the status light is almost solid green. I've tried a variety of PLA filaments from light to dark, same result. I hit "Resume" and the print keeps going fine.

The prints themselves comes out nearly flawless, like most things printed on the Railcore. I've tested with and without the sensor enabled on smaller items....they look identical coming off the plate, so I do not think the filament is under/overflowing at any time during the print, at least to my eye.

Based on suggestions in other threads, I changed slightly to this new configuration:

M591 D0
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 25.10mm/rev, allow 50% to 150%, check every 5.0mm, version 3, mag 130 agc 80, measured sensitivity 25.10mm/rev, min 91% max 107% over 22108.7mm

This went better, and on a 32 hour (scheduled) print it only stopped three times...but one was overnight so I lost several hours in standby until I could hit "Resume", which is a bummer.

Last night I hit "M591 D0 P0" during a long print to disable the sensor overnight, then re-enabled it in the morning and it ran fine (one more stop) before finishing a few minutes ago....but disabling it kinda defeats the purpose.

Just curious if this is more of a configuration / tuning issue, or is there something maybe with the wiring (too long?) that could cause an intermittent bad signal? Is the error calculation somehow cumulative, so eventually the small errors build up into a larger one that hits the threshold?

Overall happy with the unit and it seems like it's doing it's job very well....I just need to dial it in to avoid these false alarms on long, overnight prints.

Thanks!
Chris

Good morning Duet collective,

I too am having some calibration issues for the rotating magnetic sensor. My setup: New-ish Railcore printer, BMG extruder, v1.7a magnetic sensor board mounted just before it, black FDM self-printed case sanded down to achieve AGC of ~80-81. There is an approx 1m wire from the sensor back to a Duet Wifi v1.02 board, running firmware 2.05.1 per a previous recommendation.

My issue is inconsistent triggering of the stop actions.

I started with this somewhat generic but tuned config:

M591 D0
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 25.20mm/rev, allow 70% to 130%, check every 3.0mm, version 3, mag 130 agc 81, measured sensitivity 25.10mm/rev, min 96% max 105% over 446.9mm

In this configuration I get no more than 20-30 minutes of runtime before it bombs out with "Too little extrusion", "Too much extrusion", or "Sensor not reporting"...? When extruder gears are turning, the status light is almost solid green. I've tried a variety of PLA filaments from light to dark, same deal. I hit "Resume" and the print keeps going.

The print itself comes almost nearly flawless, like most things printed on the Railcore. I've tested with and without the sensor enabled on small items....they look identical coming off the plate, so I do not think the filament is under/overflowing at any time during the print, at least to my eye.

Based on some ideas in this thread (thank you), I changed slightly to this configuration:

M591 D0
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 25.10mm/rev, allow 50% to 150%, check every 5.0mm, version 3, mag 130 agc 80, measured sensitivity 25.10mm/rev, min 91% max 107% over 22108.7mm

This went better, and on a 32 hour (scheduled) print it only stopped three times...but one was overnight so I lost several hours in standby until I could hit "Resume", which is a bummer.

Last night I hit "M591 D0 P0" during a long print to disable the sensor overnight, then re-enabled it in the morning and it ran fine (one more stop) before finishing a few minutes ago....but disabling it kinda defeats the purpose.

Just curious if you think this is more of a configuration / tuning issue, or is there something maybe with the wiring (too long?) that could cause an intermittent bad signal? Is the error calculation somehow cumulative, so eventually the small errors build up into a larger one that hits the threshold?

Overall happy with the unit and it seems like it's doing it's job very well....I just need to dial it in to avoid these false alarms on long, overnight prints.

Thanks!
Chris

@toddwagner That worked great; I know I tried that setting at least 3-4 other times during my hours of debugging, but I suspect the bed height was too far off combined with the H offset being wrong, so it either turned up short or smashed into the bed. The combination of getting those two close plus the inversion of the sensor worked well. Now it homes like a champ. THANK YOU.

Might I trouble you for some hints on how you solved this? I underwent a Rostock Max V3 conversion Friday night from stock, to DuetWifi / PanelDue 7i / Ultibots FSR + JohnSL / TrickLaser bed. Stock firmware 1.21 (2018-03-21). Since late Friday night I have been chasing this exact problem with little success or change in behavior. Prior to the conversion the Rostock Max V3 was working pretty much as expected, with some expected variance in the calibration from the HE280 accelerometer (which lead me to the FSRs).

Duet install went fine, (nearly) all seems to be working as expected. FSR install went smoothly, and both the three pads and the base triggers with a light touch, and the E0 LED on the Duet blinks as well as the Z probe value changes in the web UI. I installed the rostockmax3 settings zipfile I found online, and the values for the machine (delta radius, rod length, etc) look about right. G32 lowers the head then circles the bed without probing. If I increase the machine height, it digs into the bed and drags the nozzle until I kill it. If I do the auto mesh compensation in the web UI the head lowers towards X at a rapid pace then smashes into the bed until I kill it.

I do notice this in the logs on occasion:

Error: Z probe already triggered at start of probing move

I've read the forum here, as well as the tuning blog posts from Sublime Layers and dc42, and am still struggling. I generated a custom bed probe from the Escher website.

I feel like a n00b again, and I know the answer is staring me in the face and I am just too far into the weeds to see it after 40 hours.

Thanks for any tips you can provide!