Filament runout detection

thingiverse

Finally got around to build something to deal with running out of filament when printing from Octoprint (not direct from SD card) on my Ender 3 Pro. I created this bracket to use with the following switches: https://www.amazon.com/gp/product/B00MFRMFS6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I connected the two outer most connections to my raspberry pi as you can see in the pickture. The housing for the pi is: https://www.amazon.com/gp/product/B081N3V6BH/ref=ppx_yo_dt_b_asin_image_o06_s01?ie=UTF8&psc=1 Connect it to physical pins of the pi (4B) as shown in the picture. The wire guide STL is a nice to have if you want to guide the wire to the side of the frame. I use the filament sensor reloaded plugin for Octoprint and have included a screenshot for the settings for the plugin. You will also have to tell Octoprint what to do when a print is paused (for you to change filament): {% if pause_position.x is not none %} ; relative XYZE G91 M83 ; Lower extruder temp M104 180 ; retract filament, move Z slightly upwards G1 Z+5 E-5 F4500 ; absolute XYZE M82 G90 ; move to a safe rest position (use X0 and Y0 depending on your printer) G1 X220 Y220 {% endif %} And what to do when resuming a print: {% if pause_position.x is not none %} ; relative extruder M83 ; prime nozzle G1 E-5 F4500 G1 E5 F4500 G1 E5 F4500 ; absolute E M82 ; absolute XYZ G90 ; reset E G92 E{{ pause_position.e }} ; move back to pause position XYZ G1 X{{ pause_position.x }} Y{{ pause_position.y }} Z{{ pause_position.z }} F4500 ; reset to feed rate before pause if available {% if pause_position.f is not none %}G1 F{{ pause_position.f }}{% endif %} {% endif %} You configure these settings in the GCODE Scripts section of the Octoprint settings. It all works like a charm as can be seen from the example picture where I switch from black to grey filament. Seamless.