Get the two marked with a sharp punch, then use a compass to scribe the
other two.
- -
Rex Burkheimer


Dave Hinz wrote:
OK, I now know several ways not to do this. Sounds simple - 4 holes,
evenly spaced, around a circle 0.600" in diameter.

The center of the circle, I can find easily (lathe & center drill). The
edges are concentric to the center, by definition, because I turned it
on that lathe.

I marked the 0.600" circle on the face of the disk by lightly touching
it with a cutting tool on the lathe & turning the work around, scribing
a circle at the right diameter.

Now, how do I get the 4 points layed out properly from there? I can use
a center finder to get two of 'em, but how do I get the other two evenly
spaced from those points? Or, worse yet, what if I wanted 3, or 5 holes
on that circle, rather than 4?

Dave Hinz