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Valve actuator

  1. Mar 22, 2004 #1
    I am looking for a method of actuating a valve on a musical instrument. This particular valve needs to rotate 90 degrees, but on some instruments, 120 degrees.

    I will like to actuate via wire control i.e. with a embedded computer. For example, close a switch, the valve rotates 90 degrees and holds, release the closed switch, the valve returns to the original position.

    Not much force is needed.
    It can't fail.
    It is ok to require daily or weekly maintenance (i.e. oiling, but probably not adjusting), but this is 2004, is it too much to ask for 0 maintenance
    Nearly silent, something on the level the click of a hard drive.
    Has the potential to be battery powered, but this can wait for version two.

    I am not asking you guys to my work for me. And I am sure that there are 1000 possible solutions.

    I am just asking for specific keywords that I can use to search the internet. Any specific manufactures?

    A solenoid or maybe a stepper motor seems promising, but they are slow, noisy, and more powerful then I need.


  2. jcsd
  3. Mar 22, 2004 #2


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    From your description, you're not making it entirely clear what you're looking for.

    Something that adjusts what note you're playing on a saxophone (for example)?

    Can you draw a picture of what the mechanism needs to do, and what you mean by 90 and 120 degrees?

    It would help.

    Also, everything fails eventually. How important is it that it not fail, and how long does it need to last? If you know something will be safe-life for 2 years, will you be able to change it out?

  4. Mar 22, 2004 #3

    The rotor is cylindrically shaped. Picture the circle that “defines” the cylinder. The axis of rotation is the center of the circle. The diameter of the circle is about 2cm, the height of the cylinder is about 2.5-3.5 cm.

    There is a stop arm attached to the axis of rotation and extends 0.5-1r parrallel to the plane defined by the circle. This motion of the stop arm leads the cylinder to select between two possible positions.

    A lever is pressed that is connected directly to this stop arm, which rotates the cylinder 90 degrees. To answer your question, on some rotors, the range of motion is 120 degrees.

    As I see it. Either an axis of a motor is attached to the rotor axis, or a solenoid part is attached to the stop arm in a similar manner as the manual lever.

    Now, one special property of the rotor is that its range of motion is restricted by some bumpers that prevent the stop arm from rotating more then the needed 90 (or 120) degrees.

    I will photograph this, as a photo is worth 1000 words (this being 213)…

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