Indirect Filament Sensor using Duet3D Laser Filament Monitor:

The Duet3D Laser Filament Monitor is a neat little gizmo, but it cannot handle change in filament type/color/etc. well. This could lead to false positive under extrusion reports

https://duet3d.dozuki.com/Wiki/Duet3dFilamentMonitor_LaserVersion#Section_Housing_variations

This remix of Fractalengineer design for Pulse Generator filament sensor tries to solve the problem by placing a rotating disc in from of the laser sensor. The disc the rotated by filament movement, and thus we take out the filament type/color variation out of the picture.

I was able to get consistent readings using this method over a long print with no false positives. And the original design by Fractalengineer is great at tracking the filament movement, so this feels like an improvement over other indirect sensor. Also most of the parts are printed.