On Thursday 28 February 2019 21:03:49 Jon Elson wrote: > On 02/28/2019 05:04 PM, Frank Tkalcevic wrote: > > I have a cheap ebay $100 probe. I had doubts about the accuracy, so > > I perfomed a test probing a precision disc from all orientations. > > (The disc came from a 1"-2" micrometer - it is used to "zero" the > > micrometer). > > > > The results were pretty poor, with the error ranging from 0.3mm to > > 0.75mm. > > > > http://www.franksworkshop.com.au/wordpress/2019/03/01/touch-probe-ac > >curacy/# results > > > >> I have no way to measure how good MY probe is. > > Yes, what I need is a standard for an inside mike. That > would make it pretty easy to test several directions without > moving anything. I did set it up by creating a program to > measure two sides of a gauge block, and dialing in the > "fudge factor" in the program to compensate for the apparent > probe ball diameter. Since the Blum probe needs the ball > deflected a fair bit to register, the computed diameter of > the ball is quite different from the actual measured size of > the ball. But, it seems to work pretty well. > > Jon
Jon, have you considered setting a digital caliper to say .2500" and locking it, then clamping it down well enough it won't slip while you probe its gap. Maybe even mounting it on an upward faceing belt drive rotory table so all angles of the probe could be explored? Its not required that it be exactly .2500 inches, only that it was well zero'd before you started, and that you can read whatever it is once opened and locked. That would be the standard you are comparing the probe to. That ought to make us some smarter about probes. Backlash comp would need to be done first of course. > > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers 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> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
