Q regarding Potentiometer

Discussion in 'The Projects Forum' started by auto.pilot, Dec 5, 2008.

  1. auto.pilot

    Thread Starter New Member

    Dec 5, 2008
    I am testing a small flapping wing mechanism, using a 9v battery and motor. The rpm's are way too fast, however. Thinking it would solve the problem, I added a single turn 10k ohm linear taper pot (radio shack 271-1715). I either have the wrong size pot, or need a different solution as it is necessary to spin the pot nearly a full turn in order for the motor to start. The speed is adjustable, but the starting rpm is still too high and the remaining knob travel is nearly nothing. How can I get the motor to start at a much slower rpm and get a wider rpm band? I am open to all suggestions, including a different motor, battery or ????

    Thanks for any and all replies. This site looks like a great resource.

  2. bertus


    Apr 5, 2008
  3. jpanhalt


    Jan 18, 2008
    Your flapping wing design will require a pretty high starting torque from the motor. PWM, as mentioned, may work, but I suspect you will also need a gear/belt reduction.

    I would set the mechanical reduction ratio such that the motor at full speed (9V) gives the maximum flapping rate you need. Then, PWM to get less speed.

    Presumably, this is hand launch, or do you want it to be ROG?

  4. mik3

    Senior Member

    Feb 4, 2008
    With the 10K you can vary the voltage but it has a high resistance and can't provide the current needed for the motor to work. Thus the motor starts only when fully turn the pot to one end because at the end it has low resistance. What is the operating current of the motor?