Problem with Magnetic Sensor

ciaossu

I just purchased a filament sensor from Filastruder and set it up. My mount is not ideal according to the directions because I do not want to mount the sensor on top of the bondtech extruder that is set up as a direct drive on a Railcore. This would add a lot of moving weight. So the sensor is mounted outside the printer and there is a long ptfe tube between the sensor output and the bondtech. I was able to run 3-4 12 hour prints without issue. Now though the sensor stops and says not enough movement was detected.

Is there a way to configure the sensor to simply detect any movement over x amount of time and not try to exactly sync the movements to the print? Should I be using the switch and the magnet sensor? I tried opening up the tolerance to work over a wide range but that did not help.

Settings:
Duet3D magnetic filament monitor on input 3, enabled, sensitivity 24.70mm/rev, allow 20% to 250%, check every 3.0mm, version 2, measured sensitivity 24.82mm/rev, min 91% max 105% over 160.8mm

If you need additional information please let me know.

dc42

@RandyL said in Problem with Magnetic Sensor:

I then swapped out my .04 nozzle for a .8mm nozzle with PLA+ and things went south. I'm now seeing under runs down to 10% and over runs up to 330% My last print was like so:
Duet3D rotating magnet filament monitor v2 on input 3, enabled, sensitivity 25.05mm/rev, allow 10% to 370%, check every 3.0mm, current pos 259.8, measured sensitivity 25.27mm/rev, min 94% max 179% over 9348.6mm

How close to the extruder drive inlet is the filament monitor? It needs to be very close, especially for soft filaments such as TPU. Otherwise, when the extruder retracts filament, the filament will try to bunch up in the space between the extruder inlet and the filament monitor, instead of retracting through the filament monitor.
A 0.8mm nozzle has four times the filament flow of a 0.4mm nozzle. To get comparable performance from the filament monitor, you should increase the measurement length in proportion. So try 12mm instead of 3mm.

dc42

@ciaossu said in Problem with Magnetic Sensor:

I just purchased a filament sensor from Filastruder and set it up. My mount is not ideal according to the directions because I do not want to mount the sensor on top of the bondtech extruder that is set up as a direct drive on a Railcore. This would add a lot of moving weight. So the sensor is mounted outside the printer and there is a long ptfe tube between the sensor output and the bondtech.

That is not going to work well, because filament will bunch up in the tube when retraction occurs..

Is there a way to configure the sensor to simply detect any movement over x amount of time and not try to exactly sync the movements to the print? Should I be using the switch and the magnet sensor? I tried opening up the tolerance to work over a wide range but that did not help.

You still have the measurement distance set to 3.0mm. Try a larger amount.

taglia

Hi, a quick update from me. Duet replaced my sensor (kudos to @Roland, the swap was quick and flawless, even if I live in Singapore).

I have been using the new sensor for several weeks now, and it has saved many prints, and potentially more disastrous situations. The sensor never paused the printer without a valid reason: clogged nozzle, empty spool, and once the spool even fell to the floor.

Great tool, highly recommended.

T3P3Tony

@taglia thanks for the update

RandyL

@dc42,

Thanks for the advice. I will try increasing the measurement length as you suggest. My sensor is mounted ~20mm above a direct drive extruder and was flexing around a lot. I added a brace which helped a lot but am still having issue. I will try increasing the measurement length as you suggest.