Optical measuring experiment.

[olderdan]

For many years I had the use of a Baty Shadowgraph and wishing to replicate the ability to accurately measure form tools etc, I decided to see if a home version was possible.
A free cross-hair program can be downloaded written by Mike Lin, link https://download.cnet.com/CrossHair/...-10561218.html and is a screen overlay which works with any application either floating or fixed and as a mouse pointer if wished. NB it is always a good idea to check any downloaded programs files for malware etc before running them.
A fairly cheap Andonstar pen microscope is mounted in static position and connected to a USB port, all measurements are recorded by machine movements lining up the cross-hairs on screen, easier for those with DRO but I have used a temporary digital tyre gauge so far to keep original reference position. This also replicates a system I used at work using a VGA camera and monitor when turning complex face forms in hardened steel punches for shock absorber valve tooling.
I have tested the set up in various ways against known sized tools and have agreement in sizes. Useful to measure the flat on acme tools, and on the lathe centre line to measure O ring groove diameters and the front edge of internal taper bores etc at about a 50-1 ratio and am pleased enough with results to make some proper mountings to replace the cobbled up test ones. Obviously handy to check the true sharpness of tools and taps etc, and dare I mention splinters again.