On Tuesday 22 May 2018 08:12:51 andy pugh wrote: > On 22 May 2018 at 09:55, Gene Heskett <[email protected]> wrote: > > I don't think I've got one of those seesaws, > > Steel rule. > I still don't have one. Micrometer, dial indicator, or digital caliper do it here.
> https://www.youtube.com/watch?v=m3WWoQDGO2c Some error, the body of that chuck he has clamped the gage to, is NOT the bore holding the tap. Its motion will be the centerline of the spindle. Jaw wear may not be holding the tap dead on. Not to mention that the tip of the inverted tap he used is forged, not precision ground, and could easily be off center by more than that. I have some in my collection that are at least 20 thou off. Flea market stuff I have to sharpen everytime I use them. Theres right, good enough for the girls we go with, and wrong. His chances of being wrong are not quite zero but is good enough. My use of the g38.2 to find locations has worked well for over 15 years as long as the screws are good. So I'd have to call it good enough for the girls I've gone with. :) Its allowed me to drill halfway thru a pcb, turn the pcb over and finish the hole from the other side with no visible offsets where they meet in the middle of the boards thickness. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
