Indirect (bearing) laser filament monitor concept

JADoglio

@Adrian52 Thanks. You are right even on run out when S is set to 0 it will not stop the extruder. I did that experiment a few days ago and just forgot about it.

mitch

@Adrian52 what does the A parameter do? I don't see that defined on the reprap g-code wiki site.

droftarts

@mitch see https://duet3d.dozuki.com/Wiki/Gcode#Section_M591_Configure_filament_sensing

An (firmware 2.03 and later) 1 = check All extruder motion, 0 (default) = only check extruder motion of printing moves (moves with both movement and forward extrusion)

Ian

JADoglio

@droftarts Thanks

KipK

I'm waking up this topic, ( deleted mine also ).

Here is my version of indirect filament reading, inspired by your ideas here.

It uses an 5mm shaft hobbed gear from Bondtech and U shape bearing on the latch.
Tensionning can be adjusted from the latch.

I use it outside of my DD carriage, don't have any problem with retractions ( considering I have 0.6mm retracts this prollyt explains why ).

https://www.thingiverse.com/thing:4882602

I get readings from 188% to 266% , average 230%. Is it acceptable or should I try to read around the 100% ? I think I can tweak it by adjusting the printed wheel diameter.

dc42

@kipk you can adjust the calibration factor in RRF 3.2 and later using the M591 L parameter. See https://duet3d.dozuki.com/Wiki/Gcode#Section_M591_RepRapFirmware_Num_3.

KipK

@dc42 ho that's just perfect then.

Nuramori

@brunofporto just use a bondtech hobbed gear - that's what I use and it always engages with the filament to register movement.

KipK

That's what I use here, bondtech hobbed gear.

So after using the calibration factor + few change on the indirect casing, I now have this reported values :

measured min 93% avg 101% max 107% over 12365.3mm

Looks far better than what I ever achieved with direct reading.
I still have some false trigger because of the PTFE tube moving too fast with high acceleration, I will restrain it before the filament reader.