On Sunday 24 November 2019 20:54:11 Stuart Stevenson wrote: > I have used bidirectional compensation on several machines. The latest > on a cinci just like the blue one at MPM. It has a Cin950 control. I > collected data using a CMM connected to the X table. I put the data in > the file, restarted the machine and the machine had twice the error as > when I started. I reversed the data in the compensation table and > voila the machine looked pretty good. Repeated for Y and Z. > Collecting data for 3 dimensional correction may be problematic in > some cases. > Nearly impossible in the case of a lathe, which generally has no facility other that the stops of a QCTP to set tool height. Which is exactly why I treated the sheldons bed wear which has the effect of both tilting the carriage and allowing it to sink, as x errors only. And it seems to have worked fairly well.
But I'm thinking in terms 3 axis for my G0704 and its crooked post. Its either a lot of time scraping, or a 3D COMP but how does one actually go about measuring it. Lumberyard squares which everybody has a dozen of will never give accurate enough results. likely aren't going to be that true to each other. > thanks > Stuart > > On Sun, Nov 24, 2019 at 7:26 PM Gene Heskett <ghesk...@shentel.net> wrote: > > On Sunday 24 November 2019 19:47:33 Stuart Stevenson wrote: > > > A two (or three) dimension comp file could work wonders to > > > straighten the motion. To be able to correct Y and Z motion per X > > > motion at the same discreet points chosen for the bidirectional > > > compensation would be a very good thing. Correcting X and Z for Y > > > motion and correcting X and Y for Z motion would complete the > > > package. > > > The interpolation for the correction values would make a machine > > > motion much straighter. > > > > > > This would not perfect the machine as lead screw lost motion and > > > gib/linear (guide ways) slop would still be present until > > > mechanically corrected. > > > > > > A slight warp in the bed of a lathe would be easily corrected. > > > > Ok, but lets pull this magic rabbit back out of the weeds. Where > > might I find a good tut on actually putting it to work? > > > > Thanks Stuart, Gene. > > > > 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) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > Emc-developers mailing list > > Emc-developers@lists.sourceforge.net > > 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
