THis goes to 10K RPM? that is 167 revolutions per second. 400 slots means 70 KHz signal.
Can you design an inductive sensor that does 70KHz but is also sensitive enough for near zero RPM? Optical sensors can work up to 1MHz with no problem as they don't have any inductanve. You can buy a "C" space sensor for a few dollars In either case, optical of inductive, you want a 50% "slot" where there is as much metal left as cut away Then the "edges" of the square wave are the same in either direction. The 50% duty cycle in effect doubles the sensor resolution. Why? Think about the signal when the direction changes. You have two sensors in quadrature and lets say one is being blocked and one is not, I think you want the turnaround to take as long for each sensor. On Sun, Mar 27, 2022 at 2:22 AM Andy Pugh <bodge...@gmail.com> wrote: > > > > On 27 Mar 2022, at 08:09, andrew beck <andrewbeck0...@gmail.com> wrote: > > > > And is bigger dia better for higher resolution? > > Probably not, as it will perhaps have more scope to oscillate at 10,000 > rpm. > > Don’t neglect the purely mechanical design of this fast-spinning part. > > Have you considered optical sensors rather than inductive? > > What will be counting the pulses? > > LinuxCNC can lathe-thread with one sensor. > But rigid-tapping is different as it needs to accurately detect the > reversal point. So you need three channels for index and full quadrature. > > Work out what error you can accept in the reversal point detection (as a > fraction of thread pitch) and you can get a feel for how many slots you > need. > > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
