I make the master cams (lobes) with one of my machines since it's built for the purpose too. Then I use the same masters on the other machines. The pivot lenght is practically the same, I think the worst case is 1 or 2 mm of difference between machines. Also, I use the same range in diameter for the grinding wheels in all machines, so there is no difference between the original camshaft, and the ones that we build.
If I want to digitally capture the function of the cam (lobe) I would preffer to make a little device for that purpose. One thing to study there is the way the follower in that device changes it's tangential point with the cam (lobe). This I think the most complex part in capturing the function, but with that resolved, you can capture almost any lobe. I suppose that the component to make the change in position based on acceleration would have to use certain control points and between those points fill the curve with a smooth path, so it would be a spline. That's were I don't know how to start, because it's a little advanced for me, but really interesting. Doable I think, since Linuxcnc proved to handle very well things that seem more complicated. Leonardo. 2013/5/29 jeremy youngs <jcyoung...@gmail.com> > http://www.youtube.com/watch?v=88CgdUkrk3s > > here like this . if you set ti up to use a master lobe you can machine the > lobe on a cnc mill then machine it off the master lobe and produce any cam > you want > > > On Wed, May 29, 2013 at 3:38 PM, jeremy youngs <jcyoung...@gmail.com> > wrote: > > > do you have a master cam? if so you could just build a cam duplicator > > > > > > > > On Wed, May 29, 2013 at 2:24 PM, andy pugh <bodge...@gmail.com> wrote: > > > >> On 29 May 2013 18:49, Leonardo Marsaglia <leonardomarsagli...@gmail.com > > > >> wrote: > >> > >> > 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. > >> > >> There are voice-coil servos, but I doubt they have enough force. > >> > >> I would actually be tempted to try a servo motor and crank on top of a > >> conventional X-axis. > >> In a rare move away from CNC, the crank throw would probably need to > >> be manually adjusted to suit the total cam lift. > >> > >> For a simple eccentric this would only need to rotate at constant > >> speed in exact phase with the spindle. > >> As your cam profile deviates from the simple eccentric, then the > >> relationship between the angular position of the two motors needs to > >> be modified. > >> > >> Here is a HAL component that could apply this modification: > >> http://www.linuxcnc.org/docs/devel/html/man/man9/lincurve.9.html > >> > >> It isn't ideal as it stands, it would need to be able to read cam > >> profiles in from a data file. > >> > >> I think that mechanically this is a lot less challenging for the servo > >> and controllers, the motor never changes direction, it just slows down > >> and speeds up relative to the spindle. > >> > >> -- > >> atp > >> If you can't fix it, you don't own it. > >> http://www.ifixit.com/Manifesto > >> > >> > >> > ------------------------------------------------------------------------------ > >> 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 > >> > > > > > > > > -- > > We conclude that the Second Amendment protects an individual right to > keep > > and bear arms. That right existed prior to the formation of the new > > government under the Constitution and was premised on the private use of > > arms for activities such as hunting and self-defense, the latter being > > understood as resistance to either private lawlessness or the > depredations > > of a tyrannical government." - U.S. Court of Appeals, D.C. Circuit, March > > 9, 2007 > > > > > > > > jeremy youngs > > > > > > -- > We conclude that the Second Amendment protects an individual right to keep > and bear arms. That right existed prior to the formation of the new > government under the Constitution and was premised on the private use of > arms for activities such as hunting and self-defense, the latter being > understood as resistance to either private lawlessness or the depredations > of a tyrannical government." - U.S. Court of Appeals, D.C. Circuit, March > 9, 2007 > > > > jeremy youngs > > ------------------------------------------------------------------------------ > 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
