Products Dro-350 Images Dro4
Kit for reading digital scales usually found on eBay (and later for use with a mill)…

The DRO-350 is a three-axis digital read-out (DRO) for import Chinese scales and most quadrature encoders that is designed to be as capable as commercial DROs but be a low cost alternative for the metal-working hobbyist. The DRO-350 is a do-it-yourself (DIY) project, not a complete, commercially manufactured product. All of the components necessary to build it are commonly available at Digikey, Mouser, or other electronics distributors. The printed circuit board (PCB) is specifically designed to use only DIP devices to make it easier for a hobbyist to assemble. The custom components needed to build the DRO-350, the bare PCB and the silk-screened overlay, are available to order on this site. The construction process is shown in step-by-step detail on the construction page and it is easy enough for somebody with basic electronics experience to build.

DRO-350 – Link.