If you don't fancy modding a digital caliper, (They really are HARD steel) you can buy DROs with horizontal scales for tailstocks, saddles etc, or vertical for Z axis on vertical mills)
My Tailstock DRO now won't switch off, (Battery removed for the present, dared not say "currently" ) so the next job on the Round Tuit is to remove, strip and clean the circuit board, and hope that it will be cured.
Howard
Edited to remove unwanted emoji!
Edited By Howard Lewis on 11/06/2018 22:28:27