Inductosyn has a major cost advantage over Accupins. It is a copper film bonded to a steel backplate. It is a photo etch process like a circuit board. The slider is the same process with a thin foil protection over it. The slider provides sine and cosine, and the scale reads displacement. They use a varnish to protect the copper left after the etching.
Scott On Tuesday, January 25, 2022, 11:55:13 PM CST, Lawrence Glaister <ve...@shaw.ca> wrote: Very cool Sam. It looks like the pin rail may be reproducible, but do you have any idea what the coil pickup structure is? Probably 3 coils... excitation, and the 2 quadrature phase or possibly many coils on a 1." spacing. The concept is very interesting if we could reproduce sensors like this at a reasonable cost. A similar product was call inductosyn I believe. https://www.maccon.com/rotary-linear-encoders/magnetic-encoders/inductosyn.html http://what-when-how.com/electric-motors/linear-and-rotary-inductosyns-electric-motors/ I have seen a similar sensor that used ball bearings in a tube. http://www.newall.com/technology/ this seems to show a good cutaway view. One idea I had was to try and use a ground ball screw as the sensor rail with magnetic pickups on several of the threads. Thus the rod providing the positioning would also provide position feedback of the nut (sensor coils ride on the nut). A slightly different idea (and probably less precise) is to use a rack as the sensor. With optical encoders being so cheap these days, its probably just an academic interest, but any ideas you have on the pickup coil design would be very interesting. cheers Lawrence VE7IT Nanoose Bay BC, Canada _______________________________________________ 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