Simple question. If you bored, say, a 1" diameter into a part mounted on your lathe, and then wanted to do an accurate chamfer, how would you go about measuring it. Say you want to chamfer out at 10° and the resulting slope is to extend 1/4" into the bore. I know how to set up the tooling, BUT, how do I precisely measure the 1/4" "daylight point". Alternatively, I could simply figure the increase in diameter at the working end. (tan 10°x0.25)x2. Okay, so now I know that the new diameter should be

1.088". How do I measure that. Seems like measuring this larger diameter would end up to be an 'eyeball' job. My eyes are old.Ideas with how to proceed would be greatly appreciated.

Thanks,

Ivan Vegvary