On Monday 13 July 2020 13:56:47 Chris Albertson wrote: > Actually making a hex head on the lathe would best be done using a > microcontroller. FPGAs can compute trig functions but I think the > method used is to first implement a "soft CPU" and then run code > written in C that uses math.h That is a silly-expensive why to > replace a $5 STM32 chip. > > But really, the Lathe spindle does not run so fast and you can write > this code as a HAL component that runs in the Servo loop. I wanted > out how I would do this last night and was stumped on the math until I > remembered the law of cosines and "SAS" triangle problems from some > class I took in the 10th grade. Look those up on Wikipedia and then > it is not hard to computer the cross slide position as a function of > spindle angle. > > The hard part is getting such a good cross slide setup with no play of > backlash
Does 2 thou count? But I'd be more concerned with following error. A cam for valve motion is not a sine wave by quite a long row of apple trees. > On Mon, Jul 13, 2020 at 9:35 AM Gene Heskett <[email protected]> wrote: > > On Monday 13 July 2020 12:00:19 Peter C. Wallace wrote: > > > > > > ROTFLMAO, Peter see's right thru us. ;-) But seriously, the FPGA > > does seem like the ideal place for such a module. On chip com with > > the chosen stepgenerator removes that particular bandwidth limit. I > > could also see it doubleing the size of the FPGA needed so its not > > going to be free. I think, not knowing the first thing about > > writing FPGA code. :-( > > > > [.. 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
