Anet A8 X Axis Optical Endstop

Video

Disclaimer:
If you're looking at this thing, be aware that this mod will require a light hardware mod, potential soldering, and a firmware tweak. Must be running Marlin Firmware!

I got mine from Aliexpress, but you can get them anywhere really.

Optical Pros & Cons:
This optical endstop uses an optocoupler, which serves as a non-contact endstop. This means that there is no concern for mechanical wear, as there is with limit switches. Another benefit is that the noise is reduced as you don't hear that thud or clicking noise when the axis reaches the endstop.

The technology of course is not without flaws. It suffers from the same conditions that a BJT will suffer from. Variance in temperature and humidity will affect the repeatability; however, it is not impactful, and we are not seeking micron accuracy as we do on the Z axis because we just want to roughly know the edge of our bed.

Modifications:
Before installing the print, I modified my left idler with a dremel