Problem with calibrating magnetic filement sensor

Frankzz

Now it is printing fine. It will not tell me if it stops extruding but I can find the height and use resurrect.

But just when the print started I got this message on webinterface

Connection Lost
The connection between the browser and your machine has been interrupted.

Reason: Unknown (SyntaxError: Unexpected token , in JSON at position 845)

Please reload the web interface to proceed.

Tried to reload, restart computer and restart router. Nothing helped.
Don´t want to restart printer in mid print.
Is this a known issue?

BoA

Got similar problem. AGC - 122. I ended up sanding resin case and the magnet sensing IC. Now agc is 56 and all problems solved.

Frankzz

@BoA
I started out with AGC 114. (See previous posts)
AGC now is around 80 and that is well within specs.

It did work fine for a while and that tells me the issue is the sensor.
But If the next sensor does the same I will try to this one more to see if it helps.
Does anyone know the lower tolerence of AGC ?

Frank

Phaedrux

@Frankzz said in Problem with calibrating magnetic filement sensor:

Connection Lost
The connection between the browser and your machine has been interrupted.
Reason: Unknown (SyntaxError: Unexpected token , in JSON at position 845)
Please reload the web interface to proceed.

What version of firmware and DWC are you running? There may be a version mismatch.

Currently supported versions are FW 2.05.1 and DWC 2.0.7 and FW 3.1.1 and DWC 3.1.1

Frankzz

@Phaedrux
The web interface has worked fine for 8 weeks when I upgraded the printer to Duet.
This happened right when I resumed a print. Have a hard time believing it has something to do with versions.

I switched off and on the wifi module in Duet and for some reason it had change the address.
Used the address the came up in the display and now it works again.

cherringshaw

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

Phaedrux

@cherringshaw Please start a new thread.