oh I am all about the technical. and let me tell you that wear vs. non wear is an argument for a very long time ago. Sensors that are optical or do not touch anything will never wear or loose their adjustment on their own. The mechanical part sees wear each and every time it is operated so it will never stop changing its position because it will never stop wearing, however slow it might be under the best of circumstances. I am a mechanic and let me tell you, I have funded and entire life and raised a family off of mechanical shit wearing down. That is the downfall to all things mechanical. Optical and inductive sensors are not subject to this or any kind of wear and 1,000,000 cycles and 50 years from now they will still perform to the same spec as when they were setup if not disturbed.

And just because you saw something on youtube doesn't make it right. I can post up youtube videos that teach the earth is flat.