Please read the complete article:
I've wanted a DRO on my lathe's cross slide for a while to deal with the back lash and confusing dial markings. I bought s digital caliper to adapt to the role, like I've seen several people do before. However, I want to make sure I still had rotation of the compound slide. I ended up mounting next to the side of the cross slide, with the caliper's readout mounted stationary to the carriage via a bolt through the base of the display.
I wish I could give directions on how to do it, but individual calipers are built differently, so there's a very good chance what worked for me won't work for you. You just need to buy a caliper and fool with it until it works.
Even though this is an annoying modification, I'd highly recommend it just for the added usability.