SummaryYou will need a couple of 3 x 20 mm adjustment screws to complete. I drilled a mounting hold in my existing Z endstop to allow it to be mounted on the stepper motor plate. I had to file a square area for the limit switch since it had to go on the other side. I suggest using PLA as it is harder and more stable than ABS. For the arrow component, make sure you start the threads so the screw goes in straight. I did this while still on the bed. Then when you thread it onto the adjustment screw, allow the screw to protrude about a quarter inch past the disc so that only the screw engages the limit switch. If you insert an M600 command at layer height Z=2.2, you can change filament colors to have a contrasting color for the arrow.How I Designed ThisI printed this at .2mm using Black and Yellow PLA. I inserted an M600 command at layer height 2.2mm to pause the print and change filament.