Optical Filament Sensor - for 1.75mm filament

Made my own filament sensor using an optical endstop, for pausing the print when filament runs out, or extruder is clogged.

I am using it on my custom made 3D printer (400mm cube print area) with a Duet WiFi board.

I uploaded the SketchUp 2017 file, if you want to make modifications.

Things you need:
1 x Optical Endstop
1 x Teflon tube about 10 cm long (or more). Cut a V shape (see pictures) in the middle of the tube. If you put a filament through the tube, the filament should be expo