Designs for a tool post indicator holder. I made one in steel, and the clamp in brass to use on my metal shaper to indicate the vise in and to get it square along with any other metal I want to get square. It can also easily be used with a lantern tool post in a lathe to indicate in work quite easily.

I just printed the layout out, glued it on some 1/2" steel bar, and cut around it with an angle grinder, then machined it to dimensions on the shaper.