I may have been too quick to declare a total victory. Here's why:
I did have a good success moving UNLOADED table in all directions with relatively low (0.0002" or so) following error. That cannot be denied. No chattering, buzzing, the system calms down instantly after motion, etc. But I also noticed something that I did not quite like: If when EMC2 is in holding position, I take my hand to the pulley of the Z axis motor, I can turn it by hand against the resistance of the servo motor. If I watch the position display in AXIS, I would say I can turn it enough to make Z move by 0.002", until the servo resistance strengthens enough to stop by hand. And I am not a particularly strong person. With the old tuning, that was not the case and servos acted in many annoying ways, but always held position so that I could not perceivably turn the servo motor pulley by hand when position was held. I wanted to hear some comments on this matter. Does it mean that my P and I are not high enough? Or what? - Igor On Wed, Sep 15, 2010 at 4:38 AM, Mark Wendt <[email protected]> wrote: > Outstanding Igor! Glad to hear you got it all tweaked now and running > fine. Yup, these guys know their stuff. > > Mark > > On 09/15/2010 01:11 AM, Igor Chudov wrote: >> OK, great thanks to all. Tonight was a great evening. >> >> First I tried to change velocity control loop (tachometer mode) on the >> bothersome Y amplifier to current (torque) control . >> >> Then things went well very fast and I was able to tune the Y axis near >> perfectly with FF1 and FF2. The f-error is not within about 0.0002" or >> so. >> >> NO MORE jacking around, no more vibration, Y stops immediately without >> any buzzing, moves smoothly etc. I was able to up the max acceleration >> too. >> >> Then I went on to Z, which bothered me too as were all axes, just less >> than Y. Current mode. The trick to get Z working right was to set >> BIAS, because Z is subject to gravity. Again, under 0.0002" f-error. >> Both when steadily moving, as well as under acceleration. BIAS, FF1 >> and FF2 were my big friends. >> >> After that, X was the last sweet target. Bye bye tachometer feedback, >> welcome current loop. After just 2-3 minutes, with better FF1 and FF2 >> I get f-error under 0.0002". Also increased max acceleration, which >> will no doubt improve small work performance and truetype-tracer >> times. >> >> I now have a sweet quiet little Bridgeport Interact mill that does not >> act like it is PMSing 30 days a month. 90 IPM on X and Y (I limited >> myself to 60 IPM on Z for safety). Quick to home and quiet. >> >> That double velocity loop, ad I now realize, was not good for what I >> was trying to do. >> >> Guys, you are AWESOME! Many hugs to all of you from beautiful Lisle, IL! >> >> - Igor >> >> ------------------------------------------------------------------------------ >> Start uncovering the many advantages of virtual appliances >> and start using them to simplify application deployment and >> accelerate your shift to cloud computing. >> http://p.sf.net/sfu/novell-sfdev2dev >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > ------------------------------------------------------------------------------ > Start uncovering the many advantages of virtual appliances > and start using them to simplify application deployment and > accelerate your shift to cloud computing. > http://p.sf.net/sfu/novell-sfdev2dev > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
