On Sun, 27 Jan 2013, Marshland Engineering wrote: > Date: Sun, 27 Jan 2013 22:24:03 +1300 > From: Marshland Engineering <marshl...@marshland.co.nz> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: emc-users@lists.sourceforge.net > Subject: [Emc-users] Servo tuning MESA 7i48 cards > > I'm running Colpey servo drives but I cannot get them tuned in with > LinuxCNC. > > 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.
This sounds like torque mode > > The manual for the drive says to supply a stepped input to it and tune the > feedback pot till the motor steps nicely without overshoot. Done this with a > 1 HZ signal generator. This is really hard to understand if the drive is really in torque mode. This behaviour sounds a little like a velocity mode servo that has no tachometer feedback That is, in torque mode, all the you can step is the motor current (and torque is proportional to motor current) so unless you are plotting acceleration, linuxCNC will not see anything like a step. With steps in acceleration you should see a roughly parabolic position, and a linearly increasing velocity. > > Now when I'm runing it with LinucCNC, I get a lot of overshoot and > eventually, if the step is big enougth, a following error. A couple of things: If you have any significant I term, a step input will cause 'integral windup' and overshoot. For this reason once you close the loop in LinuxCNC you should not make step movements (or leave I at 0 until basic tuning is OK) > > I've tried P, I and D values varying from .05 to 5 and output voltages from > 1-10 and none seem to make any real improvement. > > I'm stuck. > > Thanks Wallace > > > ------------------------------------------------------------------------------ > 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 > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ 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
