If I’m holding an unmarked V-bid in my hand, my untrained eye has difficulty distinguishing between 90° and 60°. I have a few improperly cut inlays (scraps) as a result of this error.
When I’m in Carbide Motion and I position the bit 6mm above the Z origin I never have a quick and easy way to measure that 6 mm.
The ugly little “tool” pictured below solves both of these problems for me…
Put one side the cutter on the inside flat bottom of the protractor. Move the arm against the other side of the cutter and read the angle. It’s not going to be super accurate but how many 64.1º cutters do you have? It’s a quick cheap way to determine the angle of a standard cutter most people use.