Simple filament runout sensor and cable management

Remix of Daniel Relich's simple runout sensor using an ender 3 endstop and filament guide that came with a microswiss direct drive to mount together on the original extruder mount bracket for ender 3 (https://store.micro-swiss.com/products/micro-swiss-direct-drive-extruder).

I had to modify the cutout for the original runout sensor to allow for additional space for the mounting screws and the filament track position relative to the switch (moved 0.5mm closer). You may need to modify this position depending on the sensitivity of your microswitch. Original openSCAD supplied.

Please reference Daniel's original design if remixing (note Attribution non-commercial licence).

Materials
1x 5.5mm ball bearing (paint mixing ball bearing)
Ender 3 endstop microswitch
2x 6mm M3 bolts to mount microswitch 

3x 20mm M3 bolts to mount to bracket
3x M3 nuts
2x zip ties
2x PTFE restraining collets (comes with microswiss DD kit)
2x PTFE restraining clips (comes with microswiss DD kit)

Printed in PLA+ with 0.3mm nozzle, 0.2mm height, no supports
Tip: print cable guide vertically.

Installation:

1. Insert the ball bearing and mount the microswitch in the sensor and secure with 2x 6mm M3 bolts 
2. Test the microswitch by inserting some filament and making sure the switch triggers. If not you may need to adjust the track position in the SCAD provided.
3. Insert short piece of PTFE tubing, collet and fix with restraining clip so that the filament doesn't run into your z-screw (see pictures)
4. Mount cable guide and sensor to the bracket using 3x M3 screws and nuts.
5. Secure PTFE tube that runs to extruder and fix with restraining clip and collet
6. fix cable with 2x zip ties to cable guide.

firmware setup for the endstop will vary depending on your controller and firmware flavour.