Here is a little caliper I made

I needed a thickness caliper to measure soundboards at various places. I obviously can't use a micrometer on a 14 inch wide piece of wood! I bought a digital gauge from harborfreight.com for about $30 and mounted it on some plywood scrap I had laying around.

While not as robust as I would've liked, it serves its purpose moderately well for now. I will do some reinforcing and re-engineering to make it stiffer and more reliable!