Filament Runout Sensor

thingiverse

I used these Momentary Roller Micro Switches. https://www.amazon.com/gp/product/B07486RHH7/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 The connector is a 2.54mm JST-XH 2 type connector. https://www.amazon.com/gp/product/B07Q86ZJ4Z/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 This is a simple two wire version (Ground & Output). You will need to set the ENDSTOPPULLUPS so the state does not float. You can use three wires on the case with the hole or widen the two connector version if you want. I would print at 100% infill and then drill the filament path to smooth it out so the filament does not catch on the layers. You can create a mount and use longer screws. If you are using the terminal connection version I would place it in the case and the quickly solder the leads to the normally open and common side of the switch. I used a solid wire to connect the NO side. You can use a hot glue gun if you want to keep it in place.