Ender 3 Filament Runout Sensor

I loved the idea of reusing the Z-Stop I had available after installing the BL-Touch. However, I didn't really like having the sensor just hanging off the filament. I remodeled the parent design from @The_Goss to mount securely to the Z-Stepper mount.

All the instructions and examples from his model still apply, then just slide this into place over the Z-axis roller spindle.

v2 - Complete mount
v1.3 - Sensor tray only for remixing into other mounts/parts

***Updated 2/7/19***
1. Added v2 STL and F3D files with integrated Z-Stepper mount

***Updated 2/6/19***
1. Fixed screw hole alignment
2. Thickened backplate to better align switch/connection
3. Fillet all the things!
4. Center and deepen connector notch

***Updated 2/6/19***
1. Loosened tolerance on PTFE cutouts
2. Added cutout for wiring connector on bottom face
3. Increased front wall thickness on tube enclosure
4. Enlarged cutout for sensor arm