On Thursday, June 4, 2015 at 12:49:56 PM UTC-7, Lloyd E. Sponenburgh wrote:
I can roughly measure a reground 3-flute or 5-flute cutter using my lathe
as a fixture, measuring the shank, then the diff to the cutting edges.

That works. But I don't own a v-mic in order to do it right. Is there
another 'standard strategy' for measuring odd-number-flutes' diameter?

I've been going through all my old texts, and they all show a v-micrometer
as the preferred method. I was hoping for some old 'shop lore' method.

Lloyd

Step one: Don't pay any attention to Jonnie Bonkers.

Mic the shank diameter.

Place shank in V-Block, put dial indicator tip on high spot of shank (center) and zero out indicator.

Move indicator to flute, measure high spot on flute, difference between shank and flute reading is radial value that value X 2 gives you the difference in diameter.

If needs be, check each flute to see what the run out may be.