2013/12/11 Dave Cole <linuxcncro...@gmail.com> > If it meets your needs then you have succeeded. :-) > > I have put AC servos on Induction Hardening machines before. The > machine you are using may be similar to the one I automated. The > shaft/camshaft moves vertically through an energized induction coil and > is sprayed with water to create harden the surface. I put a high dollar > Parker servo on one years ago and the drive went crazy when the > induction coils were energized. We tried everything and ended up > putting in a much cheaper AC servo drive and the problems went away. > :-) The induction coils induce voltage into everything that is near > the them, including cables, motors, etc. The machine frame "ground" > varies in potential along the machine frame. > > Well in this machine the camshaft is stationary and turns on its own center to get a homogeneous heating. The coil and the shower move all the way to make the treatment. The carriage is heavy and also it's suspended because the ways are on one side, so this is what makes this mechanism more noisy and rough. I mean it's not a bad machine, but it's heavy and bulky for the job. I hope I don't have that problem of the induced voltage on the VFD, we'll see that in a few days when we turn on the heater.
> If you have a similar machine, then .3-.4 mm of error is quite acceptable. > Yes indeed, I'm more than happy with this because I was affraid that tuning this could consume a lot of time but I can start to work now and improve the tuning everytime the machine is not working. The most important things are to reduce the vibration when the carriage moves up, and also find a way to reduce my following error when the joint accelerates because that's when I got the most critical following error, so If I set low values I got the problem, but if I set it high the machine works fine and I got those .3 or .4 mm of error wich is quite good. Remember that this machine worked with switches like limit switches and it had a big plate with the wedges (I don't know if wedges is ok). Anyway this was ok for the time but now I need to change the programs often and it's an obsolet sytem. Also, if you see the original motors for the positioning system you'll be crazy. The machine had a DC motor with a reductor for the precise movements when the part was being heated. And that motor also was feeded by a DC generator that was powered by another AC motor. This is only for the precise movements. When the part was finished, the coil returned to the home position by means of an AC motor. The machine switched between the DC motor and the AC motor using a electromagnetic clutch. That was a hell of KW wasted for a simple process, even for that year (1975) they could have used DC servos. Anyway, that's all gone now and I'm glad LinuxCNC is again making me happy with its result :). -- *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
