Can I use a stepper motor instead of a rotary solenoid to turn the inductor switch?
Yes. In fact, a stepper motor will make for faster and smoother operation, because it turns both in the CW and CCW directions, whereas a rotary solenoid only turns in the CW direction, (Thus, 1 CCW step of a solenoid requires 11 CW steps.) If you plan to use a stepper motor, however, note that its steps must be compatible with the inductor switch indexing. Thus, you can’t use a common 1.8 degree stepper motor, because a 30 degree indexed switch is not an integer multiple of 1.8 degrees. One option is to use a 9-position 36 degree indexed switch and to eliminate two of the minimally used taps on the coil. Then, 20 motor steps of 1.8 degrees each would advance the switch exactly 36 degrees, or one position. A second option is to use a common 7.5 degree stepper motor, since 4 steps would give exactly 30 degrees. Two possible candidates (I haven’t tried them, so make sure they’re unipolar types) are sold by MECI (http://www.meci.com) and are listed on their website. The specifications are:
