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Circular to oscillatory motion

  1. May 27, 2014 #1
    Hi all

    I'm from Bioengineering and unfortunately not too expert on the mechanical side. I'm making a device for which I need a mechanism to transform circular motion into oscillatory motion. I found the mechanism in the picture below:

    http://www.clohe-movingtoys.eu/Images/Mechanisms/leva_oscillante_1.gif [Broken]

    In my device, the oscillating 'stick' would cover an angle of 170 degrees.

    My questions are:
    Is the oscillatory motion actually sinusoidal? (ie is the velocity/position actually sinusoidal, or are they just approximated to sinusoids due to the small angle shown in the picture?)
    If it is/can be sinusoidal, is there a straight forward way to go about to find the specs (size and position of rotating wheel...) of the system?

    Suggestions on different mechanisms I could use are very welcome. (I thought of using a cam but the oscillating 'stick' would in my case probably be jumpy due to the high velocity and low weight needed).

    Thanks everyone!!
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. May 28, 2014 #2


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    Science Advisor

    More information about your application is needed. There are many mechanisms available.

    Do you need a linear or an angular oscillation?
    Do you want the angle of the lever, or the horizontal position of the end of the lever, to be sinusoidal?

    It will be difficult to get 170° from your example because it will be too close to locking up at 0° and 180°.

    What are you trying to control?
    How much real work does the mechanism need to do?
    What maximum RPM do you require?
    Scale, how long is the lever?
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