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
