I have "played" with the Arduino micro processor for a few years and never had a "real" use application for one until Chuck Fellows rotary table to dividing head. I have used his idea to make many timing pulleys for a 4 axis CNC table top I made from stuff from under the work bench. No plans. It is running GRBL through an Arduino. Next I put together a DRO using igaging scales and an Android tablet running through an Arduino chip also. TouchDRO info and downloads are available for all on line. See a theme yet? What other uses for the Arduino are there for use in the shop?