Does anyone know what technology is used on the DRO's used on metalworking machine tools? The ones I had used what they called "glass slides", one for each axis. I never took one apart to look closely, but I have searched for this and come up short. I would think this would make an interesting PIC project for all of us with home workshops.... Chris -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu