Working on my tuning I find that the vibration/oscillation I have is due to torque. The charriot that the screw is moving is vertical and weights like 100 kg so there's a lot of force for the motor to do to lift the charriot. That's when I get the vibrations, on the way up. On the other side, when I move the charriot down there is no vibration and the motor runs smooth.
I know this is due to torque but I don't know how to compensate this. If I use low speed on the way up theres almost no vibration. The vfd without LinuxCNC handled well both up and down so I don't think it's too much for the VFD and motor. Any ideas? Thanks!! 2013/12/10 Leonardo Marsaglia <leonardomarsagli...@gmail.com> > Well. I have some good news at leat based on my experience tuning servos. > I mounted the motor and now is working moving the screw (this is a SAE 1045 > steel screw with a nut made out of nylon 6). Doing a quick tuning today I > got a 0.2 mm of error and the oscillation stoped when the joint reached the > position. > > The only thing is that I'm getting vibrations during the moving of the > joint. I know I need more tuning but may be there are some tips for this. > Also I'm working at 3000 mm/m wich is half the velocity I expect but I > don't have complains so far. > > Thanks as always! > > > > > 2013/12/6 Leonardo Marsaglia <leonardomarsagli...@gmail.com> > >> I will try it with load tomorrow or next monday, because I'm finishing >> with the encoder coupling for the screw. I never tried the autotunning but >> it is supposed to tune all the motor parameters to get better torque. I >> hope that helps to improve the positioning. Anyway as I told before I don't >> need centesimal accuraty, but now I need to ged rid of that oscillation >> that doesn't stop. I will try and see what happens the I'll tell you. Off >> course I'll be uploading some videos when it's working :). >> >> Thanks as always! >> >> >> 2013/12/6 Jon Elson <el...@pico-systems.com> >> >>> On 12/05/2013 09:35 PM, Leonardo Marsaglia wrote: >>> > 2013/12/5 Jon Elson <el...@pico-systems.com> >>> > >>> >> Is this a flux vector drive, or a standard VFD? A >>> >> flux-vector drive can >>> >> perform the computations to keep the rotor excited without >>> >> moving >>> >> it. A standard VFD cannot, it has to move the motor to >>> >> excite the >>> >> induced field in the rotor. So, it will keep "dancing". >>> >> >>> > It says that is a FOC (field oriented control) ac drive, so I guess >>> it's >>> > not a standard VFD. Anyway it has a lot of options even an autotunning >>> > feature so may be I'ts not well configured to get the maximum out of >>> it. >>> > Now I have set it to work only with +/- 10 volts and without any >>> > acceleration or breaking assistance, so all the acceleration a >>> deceleration >>> > it's done by the PID of LinuxCNC. >>> Ah, then do the autotune and turn off most of the PID >>> features in LinuxCNC. >>> Don't use any I, a low P value and just a little D, and no >>> FFx. Let the >>> drive do most of the hard work. You will probably need to redo >>> the autotune when the motor is connected to a load. >>> >>> Jon >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Sponsored by Intel(R) XDK >>> Develop, test and display web and hybrid apps with a single code base. >>> Download it for free now! >>> >>> http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >> >> >> >> -- >> *Leonardo Marsaglia*. >> > > > > -- > *Leonardo Marsaglia*. > -- *Leonardo Marsaglia*. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
