Just messing around today, in case I need to do this someday.

I ground up a single point tool from an old endmill. I haven't found any dimensions for this type of tool. I used a surface grinder so I know the top is right on the center line, and has a zero rake on the top face. Ground the lead angle with the grinder also. Back side I had to do by hand. Since PathPilot graphics seem to show cutting with the lead angle, a little off shouldn't be a problem.

Considering how long it took I probably should have just turned a piece of O1 and heat treated it.

Just found a video by NYCNC that explained why I was undersize, (sharp point tool vs the proper radius for the root.) Do I lie in the tool table about the cutter diameter to compensate or enter a larger outside thread diameter in the to compensate?

Is my Z zero point the sharp edge or would it be the bottom of the tool. I had set it by eyeball to the sharp edge but it did not mill as deep as I thought it would. If I had set from the bottom of the tool it would have been off even more. I am not clear how to predict how deep in Z the end of the pass will be. With either a flat bottom or a short tool this could be a problem,

Dave