Filament sensor
thingiverse
Simple filament sensor, for tiny microswitches you get for next to nothing at places like dx.com or banggood.com. Can easily be connected to octoprint on raspberry pi. Made specifically for these: http://www.dx.com/p/diy-0-5a-125v-250v-micro-switch-black-10-piece-pack-120309
Download Model from thingiverse
With this file you will be able to print Filament sensor with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Filament sensor.