> > I don't think that there is much benefit in servo-ing this element of > the machine. > I would suggest that a simple (long) flag on the bull gear could be > used to determine if the machine is on the cut or return stroke, with > feed-hold asserted during the cut stroke. Otherwise you might as well > retain the original motor. > > A rotary axis to mount on the table might be useful, though. As might > a second one on the ram, for use in gear-shaping operations. >
The primary reason for servo control of the ram is to enable it to stop motion while fully retracted. This could be achieved by VFD I suppose. Alternately the operator could just turn the bull gear by hand as is done presently. You're right, a flag or encoder could also be used with the standard (single phase) motor. Is it possible to simply assert feed-hold during cut? I assume that the feed rate would be equal to the commanded feed rate whenever feed-hold is not asserted? The rotaries on the ram and table are definitely useful, but a bit more than I'd like to bite off initially. And not necessary for the production use case. On Thu, Jan 26, 2023 at 12:25 PM andy pugh <bodge...@gmail.com> wrote: > On Thu, 26 Jan 2023 at 15:26, Matthew Herd <herd.m...@gmail.com> wrote: > > > The general concept is to put an encoder on the bull gear (which has > fixed > > timing with respect to the stroke of the ram), use a large servo as the > > drive motor (although a VFD & 3 phase motor would also work, but this > > allows easy positioning of the ram and I already have a servo with ample > > power and torque). > > I don't think that there is much benefit in servo-ing this element of > the machine. > I would suggest that a simple (long) flag on the bull gear could be > used to determine if the machine is on the cut or return stroke, with > feed-hold asserted during the cut stroke. Otherwise you might as well > retain the original motor. > > A rotary axis to mount on the table might be useful, though. As might > a second one on the ram, for use in gear-shaping operations. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1912 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Matthew Herd Email: herd.m...@gmail.com Cell: 610-608-8930 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
