I set the default acceleration in the [TRAJ] sewction down to 1.8 . That made a big improvement. I also worked over the X axis, on the machine, checking the gib setting and ball screw setup and found there were problems there. After correction I am now down to < .002 difference between commanded position and actual position at the end of the run. I am elated. Thanks for every ones help.
Jack Ensor Gene Heskett wrote: >On Sunday 13 May 2007, Jack Ensor wrote: > > >>Thanks for the suggestion of trying 0.0 backlash. That cut the error >>down significantly. Why should that make such a difference? Backlash >>compensation error shouldn't be cumulative , should it? >>I am now getting from .0101 to .0002 variance. Still more than I would >>like to see. >> >>Jack Ensor >> >> >> >The one item that sorta jumped at me in the .ini you posted was that the >default acceleration in the [TRAJ] section was quite high. Backlash motions >are finally done under the same accel settings now whereas before they were >pumped out as fast as the generator could make them. So even at a 15 >setting, that may be too much. I'd try pulling that down to a few percent >less than the maximum of each axis just so the axis had some headroom to keep >up. > >I could also be full of it. :) > > > >>Chris Radek wrote: >> >> >>>On Sun, May 13, 2007 at 09:57:08AM -0400, Jack Ensor wrote: >>> >>> >>>>However when I run axis.ngc, the ending x and y positions are at >>>>variance from the commanded positions and each time I run the program >>>>(after first homing), I get different variances. I calculated the >>>>variances by subtracting the actual position from the commanded position >>>>and x can vary from -.148 to +.009, while y can vary from .063 to .008. >>>> >>>> >>>What version of EMC2 are you using (Help/About will tell you) >>> >>>Have you tried without backlash compensation (BACKLASH=0.0)? >>> >>>Chris >>> >>> >>------------------------------------------------------------------------- >>This SF.net email is sponsored by DB2 Express >>Download DB2 Express C - the FREE version of DB2 express and take >>control of your XML. No limits. Just data. Click to get it now. >>http://sourceforge.net/powerbar/db2/ >>_______________________________________________ >>Emc-users mailing list >>Emc-users@lists.sourceforge.net >>https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > > > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
