Hi folks,
After struggling to bore a few holes to a specific depth I decided I needed a carriage DRO and a leadscrew handwheel, and came up with this:


I've seen various similar mods on the internet, though often people make the "screen" of the modified digital calipers the static bit, and make the scale slide back and forth, resulting in the weird scenario that the scale slides off beyond the end of the lathe. I have clamped the scale and attached the "screen" to the carriage.
Various tests with DTIs indicate that it works perfectly in one direction, however, I have 0.05mm of backlash when changing directions. A range of tests with DTI's confirms that the "screen" on the calipers is not moving initially, which I believe is because it's rotating instead...
I heard a rumour that these calipers all have a thread on the rear for attaching things to, which is usually covered up with a conversion chart sticker. Because my linkage operates below the axis of motion of the thing, I think it's rotating it back and forth, so will look into moving the linkage to attach to this thread, if it exists!
Also made this quick-remove chip guard thing, need to make another to protect the DRO too:

Cheers,
Rich