Ender 3 Filament runout sensor and guide with bearing optimized for 1.75mm

thingiverse

I used the original thing for some time, but then 2 long prints suffered from under extrusion. I figured out, that the filament got stuck between the lever of the micro switch and the wall. So i measured everything. The space for the filament to be guided through in the original design is 4 mm. The roll on my micro switch is 3 mm. Plus the lever can easily moved sideways. The combination led to the filament to be stuck sometimes. Moreover the guide was lifted from the mounting position sometimes. So i changed following: - Reduced the space for the filament from 4 mm to 2.4 mm. - Added a hole for cable-tie mount (as can be seen on the picture). The cable tie can be up to 3mm broad. Please take all the information from the original thing - it's all the same. You still need no support. Scale with 10 %. Others commented that the switch is always activated and on some remixes they adapted this. I did not as simply bending the lever a little can fix this.