The problem with the short travel on the machine is that, it's fine for making the camshafts, but as the wheel get's smaller because of the dressing passes I need to move the X axis closer to the workpiece.
Anyway I don't see too much room for a linear motor since the machine now has a piston, I don't know if there is in existance a linear servo motor with the shape of a piston, all circular or something like that, they must exist anyway. If that exists then it could be installed, if not the best way is the ballscrew. 2013/5/29 Dave <e...@dc9.tzo.com> > I've done a machine with linear servos and they would be perfect for > what you want to do if you can get them with a high enough force rating, > but they are very expensive in longer travels. > Since you have a very short movement range you may want to check on some > pricing. > > Dave Cole > > On 5/29/2013 12:54 PM, Leonardo Marsaglia wrote: > > The maximum lift we are machining is about 12 mm and maximum diameter is > > about 45mm . And may be some eccentrics on some camshafts but nothing too > > big. > > > > The subject I am worried about the most is the one about how to generate > > the g-code, because if I want the X axis to follow the profile on the cam > > but with acceleration and velocity values, like the diagrams of a real > cam > > (lobe), then it's a little tricky. For that I would need to make some > > programming on hal because that would be handled directly from the PID > > loop. Also I need to capture the exact shape of the cam, that's not that > > tricky. > > > > About the roughing pass, that would be much more easy since I can > generate > > the profile in a cam software and compensate the radius of the circular > > mill to make the shape. > > > > About the hydraulics, yes, I think using a servo motor would be the best. > > Mordern landis machines use powerful linear servo motors but I think > that a > > ballscrew that has one or two cents of a milimeter will do just fine for > > the job. > > > > > > > > > > 2013/5/29 Dave<e...@dc9.tzo.com> > > > > > >> Doing that with hydraulics would be very, very expensive compared to an > >> electric servo. You would need a constant pressure pump, accumulator, > >> and a very expensive servo valve to get that > >> kind of speed. Big $. > >> > >> Dave Cole > >> > >> On 5/29/2013 12:18 PM, Leonardo Marsaglia wrote: > >> > >>> Yes, thinking it fast I assume that a 4 kw servo motor and ballscrew > will > >>> do it. Also there's the possibility of using the same hydraulic piston > >>> > >> that > >> > >>> the machine has but with a servo valve and a linear way. I've seen > that a > >>> guy here on the list did that to a intetrior grinding machine and It > >>> > >> worked > >> > >>> pretty well, but this is not the same kind of movement, he only used > the > >>> > >> Z > >> > >>> axis to make the plunge. > >>> > >>> > >>> 2013/5/29 Les Newell<les.new...@fastmail.co.uk> > >>> > >>> > >>> > >>>> I don't see any problems with that sort of spindle speed. The normal > PID > >>>> loops will maintain pretty good tolerance. If your X axis is heavy you > >>>> will need a reasonably powerful motor to provide the acceleration. > >>>> > >>>> Les > >>>> > >>>> On 29/05/2013 13:36, Leonardo Marsaglia wrote: > >>>> > >>>> > >>>>> About 120 RPM for the first tenths of milimeter, and then 50 rpm for > >>>>> > >> the > >> > >>>>> last turns to finish it. This machine has no VFD, it uses a two speed > >>>>> electric motor and I use it as it was originally. I can make it go > >>>>> > >>>>> > >>>> faster, > >>>> > >>>> > >>>>> but approximately that's the velocity I use to make them based on the > >>>>> diameters I use. > >>>>> > >>>>> > >>>>> > >>>> > >>>> > >>>> > >> > ------------------------------------------------------------------------------ > >> > >>>> Introducing AppDynamics Lite, a free troubleshooting tool for > Java/.NET > >>>> Get 100% visibility into your production application - at no cost. > >>>> Code-level diagnostics for performance bottlenecks with<2% overhead > >>>> Download for free and get started troubleshooting in minutes. > >>>> http://p.sf.net/sfu/appdyn_d2d_ap1 > >>>> _______________________________________________ > >>>> Emc-users mailing list > >>>> Emc-users@lists.sourceforge.net > >>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>> > >>>> > >>>> > >>> > >>> > >>> > >> > >> > >> > ------------------------------------------------------------------------------ > >> Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET > >> Get 100% visibility into your production application - at no cost. > >> Code-level diagnostics for performance bottlenecks with<2% overhead > >> Download for free and get started troubleshooting in minutes. > >> http://p.sf.net/sfu/appdyn_d2d_ap1 > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > >> > > > > > > > > > > ------------------------------------------------------------------------------ > Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET > Get 100% visibility into your production application - at no cost. > Code-level diagnostics for performance bottlenecks with <2% overhead > Download for free and get started troubleshooting in minutes. > http://p.sf.net/sfu/appdyn_d2d_ap1 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- *Leonardo Marsaglia*. ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
