The SONY website show some of their scales with coeff of expansion = steel and apparently others that match who knows what! MMS a couple of months ago show an approach where there was a shop made gage that ran alongside the long work pieces and was probed before each job to determine expansion corrections. Not the easiest thing and pretty expensive for a one-off but for long term production it will work.
Good luck. Dave On Jan 21, 2008, at 11:51 AM, Jon Elson wrote: > Stuart Stevenson wrote: >> >> The scales are SONY scales with an MD10A interpolator on them. >> The >> interpolator gives a max resolution of .5 UM. .5 micrometers is >> 0.00002 inch. I don't know what the interpolator is configured >> for. It >> can be configured for .5, 1, 2, 2.5, 4, 5, 10 UM. >> >> > OK, then, that solves THAT problem. At .5 um you get 50800 > counts/inch, which should be good enough for nice smooth movement. >> >> I have DAC output from the ppmc boards to the A/B ac servo >> amps. I >> don't have motion yet. I am a lot closer. We will try to determine >> why >> the amps don't output later today. > Unless the ballscrews have a lot of slop, you should be able to > make it run just on the linear scale. Maybe much over 2 > thousandths of an inch would get to a lot of rattling or > excessive use of deadband. I assume these amps have tach feedback? > > Jon > > ---------------------------------------------------------------------- > --- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
