On Wednesday 11 December 2013 13:50:30 Leonardo Marsaglia did opine: > Well. As you say it's not the best to use an induction AC motor for a > servo work but I managed to get 0.3 or 0.4 mm of error wich is pretty > cool for the job. > > I tried using the pid BIAS as Andy told to decrease vibration but > nothing happened. Also tried decreasing the servo thread speed as Gene > said but didn't help either. > > I think the best here is to avoid the resonance speed as Jon told, > because if I increase the rapid to 9000 mm/min (wich is a lot) I have a > lot less vibration. This happens also when I decrease it to 1500 > mm/min. > > I guess with a better tuning I can get better results but I have a lot > to learn about servos, also there's the inherent limitation of the AC > motor. But I don't have to forget that the charriot it's vertical and > weights a lot, we even tried with a person standing over it and behaves > in the same way so it will work ok with the induction transformer that > has to be on it. > > I'm happy because it's going to work really fine for the job, most of > you already know that I was automating a machine for case hardening on > camshafts. And may be in the near future I can install an AC servo > since this VFD can handle permanent magnet motors too. > > In the next few days I'll be uploading some videos to show you how it > works and how is the machine. Also I would like you to see it fully > working with the induction heater on it! > > Thanks as alway!! > It sounds like an interesting project Leonardo, so please post a link.
Question: Is this enough of a velocity variation to effect the performance of the hardening process? Or cause premature wear anyplace from the vibration, like in the cable trough feeding this carriage? Maybe this is a case where the vibration dampers on the rear end of our steppers that are often used, might be expanded into a damper big enough to absorb the majority of this "vibration'? This damper gismo isn't an area well characterized, or at least I've not found someone proposing formulas for their making on the net, so most of use make our own according to our own thinking. If the rear shaft isn't available, then a thin flywheel on the drive end, with a tubular rim filled with large ball bearing balls for rolling weight, running in heavy grease to dampen the motion of the balls relative to the rim could make a noticeable difference, but with the reduced rate of available acceleration that swinging weight would cost. Not talking my nema 23's here, where such a constuct might be the size of a roller skate weheel but something perhaps 8 to 10" in overall diameter, keeping in mind it needs to strong enough to take the rpms involved. It goes without saying that its demise at speed would of course become quite a hazard. :( Containment cages could be indicated/demanded by the safety people. Just an old fart, thinking out loud, I'll go away now. ;-) > > > 2013/12/11 Kirk Wallace <kwall...@wallacecompany.com> > > > On 12/11/2013 09:40 AM, Dave Cole wrote: > > ... snip > > > > > Siemens had hybrid motors that were not > > > standard induction motors at the time that could do better > > > positioning but they were as expensive ore more expensive than > > > other companies servo drive systems and were generally only used > > > for very large HP/torque applications that required some level of > > > positioning at high power levels. Think big $$. > > > > > > Dave > > > > Speaking of getting creative with induction motors, I found this > > recently. It may be of interest. > > > > http://powerelectronics.com/power-management/how-run-split-phase-induc > > tion-motor-three-phase-inverter > > > > > > -- > > Kirk Wallace > > http://www.wallacecompany.com/machine_shop/ > > http://www.wallacecompany.com/E45/ > > > > > > ---------------------------------------------------------------------- > > -------- 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.c > > lktrk _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> Another Armenia, Belgium ... the weak innocents who always seem to be located on a natural invasion route. -- Kirk, "Errand of Mercy", stardate 3198.4 A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ 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
