Ender 3 Klipper Conversion – Stage 7 – Filament Runout Sensor

Basic filament sensor made from a micro switch.

Get a micro switch and solder wires to its two ends. In a more technical expression:

Common terminal – Normally Closed terminal.

Print a housing for the micro switch:

Install the micro switch:

Connect the switch wires to the BTT SKR mini E3 v3.0

Find the E0-STOP connector then locate the PC15 pin and GND next to it.

Add runout sensor lines to printer.cfg file

[filament_switch_sensor filament_sensor]
pause_on_runout: True
switch_pin: PC15

If everything was done correctly then a Filament Sensor line is now visible under the Miscellaneous section within the Dashboard.

It shows empty when no filament is running through:

It shows detected when filament is going through: