Lightweight Filament Runout Sensor With Instructions for Octoprint

After having a long print failure i thought it was time to finally get a runout switch. I didnt find anything I really liked that worked with the limit switched I had. 

-Assembly-

Just print both halves as oriented in the files (support may be needed depending on your bridging capabilities) and screw together with M2.5 screws and nuts.

-Wiring to Raspberry Pi-

Be careful not to wire to 5v or 3.3v. That can cause the GPIO Pinout of the pi to die. Only wire to a GPIO pin and ground!

On the limit switch connect NO (Center Pin) to GPIO and C (Pin farthest from the roller) to ground. I connected them to physical board pins number 18 (GPIO) and 20 (Ground). 

These are the limit switches I used, model KW12-3 available on amazon for $6 for 10 of them.

-Plugin Setup-

I used Filament Sensor Simplified which you can install through the octoprint plugin manager. Once installed You will want to set it up like this assuming you have it set up the same as I mentioned above. 

Board Mode - Physical/Board mode

Pin Number - 18

Sensor is connected to - Ground

Switch Type - Triggered when open

For the filament run out action I have it send the M600 gcode command. 

Make sure to click “Test sensor” after installation. If everything if good it will say “Sensor triggered!" when the sensor is ready to detect filament in this configuration and ”Sensor detected filament!" when the filament is detected in the sensor. 

Afterwards do a test print and have it run out of filament and it would work like a charm. Depending on how tight you screwed together the halves you may have trouble when it unloads but since it just sits next to the extruder it wont matter if it gets caught going back up.