Super. Thanks John > -----Original Message----- > From: John Figie [mailto:zephyr9...@gmail.com] > Sent: January-01-18 4:25 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] 240V single phase input vfd > > John, > > To be clear you need either closed loop servos or steppers on all of the > motion axis for CNC control. The spindle however can be open loop just as > Jon said. A spindle encoder essentially allows all other motion to be > electronically geared to the spindle motion. You can run linuxCNC without a > spindle encoder but then you cannot do ridged tapping or threading. > > > > John Figie > > On Mon, Jan 1, 2018 at 6:06 PM, Jon Elson <el...@pico-systems.com> wrote: > > > On 01/01/2018 05:59 PM, John Dammeyer wrote: > > > >> Most of those VFDs appear to be open loop. > >> > >> What's normally done with LinuxCNC for closed loop spindle control? Say > >> you want to do the equivalent of internal threading on a lathe. Is a > >> run-out area required or can LinuxCNC control the spindle speed in sync > >> with the Z axis so either a tap or cutter follows the threads? > >> > >> Is an AC Servo (with encoder) even required on a CNC system or just open > >> loop variable speed control? > >> > >> > >> I run entirely open-loop, and it works fine. You do need a spindle > > encoder for any threading operation. > > On my minimill, the spindle slows noticeably when threading, but the Z > > axis stays in synch with the spindle, > > and it works fine. You need both a "run-in" and "run-out" distance, as > > the Z axis cannot start and stop > > instantly. > > > > Jon > > > > > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ---------------------------------------------------------------------------- -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users
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