On Wednesday 21 October 2020 00:00:07 Scott Harwell via Emc-users wrote: > The KB drives are solid. They have been around for many years and > work well. The last one I used was for an index motor on a large lathe > and it ran for years no problems. I don't think it is fast enough for > a servo. Scott H > And the one in my x1 micromill is not scr based, its a switched mode power FET version, and its for sure fast enough to run a servo. Controlled from linuxcnc by a pmdx-106 interface, its up to full speed of 2500 revs in under 50 millisecs from dead stopped. Either direction.
The reason I know is that I blew the FET, and replaced it with one from a duff pc power supply. That was 6 or 8 years ago and its still working. I am among other things, a C.E.T., so replacing the blown FET was not a problem for me. > > On Tuesday, October 20, 2020, 7:00:00 PM CDT, Dave Cole > <linuxcncro...@gmail.com> wrote: > > > I didn't think that we were talking about positioning. > I thought you were talking about a spindle drive. > I think it could be used as a low performance positioning drive. > You would need an opto coupler setup for the command obviously if > there is no isolation. > I'm not sure that the newer KB drives aren't isolated. > But I would probably pursue a real servo drive/motor if you want > anything with performance. > In the past few years I have implemented AC VFDs on some machines to > do positioning. > They use a relatively high ratio gearbox. They are usually in vector > mode. Those setups can last a very long time. But they aren't super > precise, but then they don't need to be. > A couple of the machines used shot pins to get precise final position. > > Dave > > On 10/20/2020 5:30 PM, John Dammeyer wrote: > >> From: Jon Elson [mailto:el...@pico-systems.com] > >> > >> On 10/20/2020 03:19 PM, John Dammeyer wrote: > >>> I looked at their web site. (google KB Electronic DC drive). > >>> Seems like pretty nice stuff although I wonder if they would react > >>> fast > >> > >> enough to a closed loop control. If that was even wanted. One of > >> the drives does support tachometer feedback. The KB drives are SCR > >> based, so pretty low bandwidth. > >> > >> Jon > > > > So perfect for treadmills or fans or conveyers or any sort of simple > > speed control with a knob. But not ideal for CNC based systems. > > > > John > > > > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
