> > 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.
I remember the first time I took a look at your oval comp I started to calculate the radius compensation for the grinding wheel. I only did it in solidworks with lines and triangles but it worked. The good thing is that for eccentrics you only use equations but for the different lobes/cams I have I can only get the control points. I would love to have the possibility to extract the data from the lobes in the form of a function defined in parts. Now I can only rely on acquire the lift in intervals of 5 degrees and complete the spline using software. Then export that curve with the number of control points I need. But reverse engineering the equations seems to be a pain in the ass and I don't know how much of an advantage that would give me. > > El sáb., 21 mar. 2020 a las 18:46, Leonardo Marsaglia (< ldmarsag...@gmail.com>) escribió: > correction whenever, scale is encoder input A count for 100 turns, >> divided by 100, do not throw away the decimal fraction. >> In my ini file under [SPINDEL] i HAVE: >> ENCODER_SCALE_H = 7161.61 >> ENCODER_SCALE_L = 14095.34 >> and: >> SCALE_UP = 1.96818033933710437 >> SCALE_DOWN = 0.508083522639397134 >> > > Indded I didn't and I try to use the more decimal numbers the calculator > allows me to use. Fortunately I only have 1 gear on the Mazak, but anyway > the encoder is directly coupled to the spindle shaft with a timing belt so > no issues with that matter. Its working flawlessly now that it has the > original control so it should do equally right with LCNC. The beauty of > having a continuous curve for lobes drawn in autocad is that I can export > them with the amount of points I want so I can match the encoder exactly. > Now I'm doing fine with 512 control points, but If I want I could use the > 1024 pulses of the encoder each one with a control point. > > The only thing I have left to test is how it goes on the Mazak at around > 200 RPM which is the average speed I plan to use to turn the lobes. I hope > I can go back as soon as possible to install the new control and start the > real machining :). > > El sáb., 21 mar. 2020 a las 17:15, andy pugh (<bodge...@gmail.com>) > escribió: > >> 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 180º 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. >> >> -- >> 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 >> > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
