DRcheapO

Here's an idea that's probably been done:

What about using digital calipers for a DRO? Sure, they're harder to
read, but it looks like they would do the job. Attach the fixed jaw to
the body of the machine, and attach the sliding part (with display) to
the axis, or vice versa. You would have mm/inch instantly switchable,
you could measure relative distances by zeroing, etc. If length is a
problem, MSC sells 24" calipers for US$190.

Just a thought.

Regards,
JJ

Be Kind, Be Careful, Be Yourself