Aligning A Vise on a Mill

[Toolmaker51]

The sine bar would be an improvement. It should be placed on the movable jaw side of the vise so it doesn't add error. The labor-intensive part of this for me was setting up the "nest" to prevent the pivot pin from sliding around.

Rick

Alluded to that; a Vee block 'post' weldment with a foot-bolt-Tee nut ready to clamp down, ala table mount vise stop. A real Vee could be avoided with 2 steel balls.