On Saturday 21 March 2020 16:11:44 andy pugh wrote: > On Sat, 21 Mar 2020 at 17:44, Leonardo Marsaglia <ldmarsag...@gmail.com> wrote: > > I intend to turn automotive camshafts, that is with a minimum of > > 180ยบ of base circle (sometimes called heel I think), and a maximum > > lift of about 8 mm > > In that case the high resolution encoder might be good. I doubt that > you will me machining camshafts at 20,000 rpm. > (Especially not if the cutter needs to dive in and out) > > For grinding you need to consider how the contact point rolls above > and below the centre line. I did do the maths, when I did the > crank-grinding mock-up. But only for a circular but eccentric result.
Another thought or 2 here. The weight of the grinder you'll have sitting on the crossfeed will effect your usable spindle rpms by slowing down the maximum attainable accel's. My nema 24, x on the sheldon, geared 2/1 has a 3o ipm max limit, so that motor will need a serious boost in top speed to even try doing that at 200 rpm. If room for its diameter, the use of a flat faced CBN wheel would eliminate some of the math by eliminating the calculation of the wheels up and down due to the curvature of the wheel face but I think whats available is way too big for this. The use of CBN should however lengthen the cutting life of the wheel compared to the alox versions, particularly if running wet as I have seen it done in some of the you tube videos. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
