Ender 3 Optical Runout Sensor

thingiverse

I swapped out the optical endstop sensor model for one that lined up better initially, but it still didn't fit quite right. To improve its alignment, I made some adjustments by slightly moving the holes and adding a small PTFE tubing on both sides of the body to enable smooth filament entry. For installation, I relied on two m3x12 cap screws and followed these steps: 1. Raise the gantry to the top to simplify removal of the original screws. 2. Remove the screws on either side of the lead screw behind the extruder. 3. Use the original screws to secure the optical sensor board into this sensor body. 4. Slide the assembled sensor down the lead screw and fasten it with cap screws. 5. Route the cable through your cable chain and into the mainboard compartment or raspberry pi. This design was remixed in OpenSCAD, so if you find that your sensor doesn't align with the holes, I'd be happy to make adjustments or supply the necessary files for you.