Quote Originally Posted by Sam View Post
Thanks jderson, I'll take a look at those. I'm also considering trying IR emitter/detector with a reflective stripe. But would prefer the hall sensor method.

Thanks again,

Sam
So many ways Sam, Hall effect, plain old coil and magnet glued on the shaft **, spinning disk with holes and opto, old relucter and pickup from car distributor, heck even points for low rpm application, all can be directly driven or run off an idler belt / pulley setup, who cares how many sensor triggers per revolution, you can tweak it in the software to do any math required. On my lathe I plan to put a small belt to the "encoder" from the headstock so I do not have to hassle modifying the spindle. Oh I thought of another one, if your spinning shaft has a nut spinning too aim a small magnet at the nut and a coil of wire at it at about a 60degree angle, might work as a reluctor. Or a spinning gear . . .
** Note: Remember those aftermarket Cruise Control units from the 1980s?