On Sun, 27 Jan 2013, Jon Elson wrote: > Date: Sun, 27 Jan 2013 11:59:22 -0600 > From: Jon Elson <el...@pico-systems.com> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] Servo tuning MESA 7i48 cards > > Anders Wallin wrote: >> The servo is a current drive with a +- 10 volt input. >> > ^^^^^^^^^^^^^ >>> As there is not much load on the drive so a +-0.4 volt will swing the motor >>> at full speed. >>> >>> >> >> Tuning with no load at all might be hard or impossible. Do you have the >> motors attached to the ballscrew/machine? >> Full speed at 0.4V command would mean you throw away a factor 20 of dynamic >> range. >> I'd suggest you do something to get full speed at closer to 8 or 9 V >> command - maybe lower the supply voltage to the drives, adjust the max >> current, or something. >> > No, he says he's running in torque mode, so this is probably right, for > that setup. > I'd suggest adding a tach and going to velocity mode, but if that is > hard, then you > have to tune it for torque mode. You might contact Igor Chudov, who is > using > Copley amps in torque mode with my (Pico Systems) analog interface. He > may have some suggestions. > > Jon > > ------------------------------------------------------------------------------ > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft > MVPs and experts. ON SALE this month only -- learn more at: > http://p.sf.net/sfu/learnnow-d2d > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > If the drives are indeed in torque mode (which is hard to reconcile with tuning the drives step response via a potentiometer), It may be very hard to tune a bare unloaded motor at a linuxCNC 1 KHz sample rate (~300 hz bandwidth)
Peter Wallace Mesa Electronics ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
