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Motion solution needed

  1. Jan 23, 2007 #1
    I am an MA sculpture student. i want to put motion into a piece i am working on. It involves a 7x7x60 cm solid wooden curve thats made of pine and wood glue in a ply-like style. Its curve means that either ends are aprox 40cm from the ground. I would idealy like to display the peice on the studio floor.
    I want to cause a rocking motion in it, but make it so the locomotive is unseen, inside the curved beam, perhaps in a dug out hollow. Therefor it needs to be battery powered.
    My tutor has surgested to me to use a small motor to power an egg shapped disc to rotate, tipping the beam into a rocking motion every time the tip of the egg shape touches the ground.
    Is this a good solution, and what componants would i need to create such a circuit?
    Any help on the subject would be hugely appriciated, i'm currently studying in Paris and dont speak french well enough to relay my concept to anyone helpfull.

    I just added photos of the peice so for, hope this helps.

    Attached Files:

    Last edited: Jan 24, 2007
  2. jcsd
  3. Jan 24, 2007 #2


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    It would help if you could post a sketch of what the sculpture looks like and how it is displayed. For example is it on the ground, on a table or a stand, suspended from the ceiling, etc...

    One problem with your idea is that there may be friction between the disk and whatever it is pushing against as it tries to rotate. You could fix that by making the disk push against another disk or a roller that was part of the stand for the structure.

    The disk idea could also work without touching anything, by moving the centre of gravity if the structure was balanced like a see-saw.

    You would need a battery, a motor, probably a large ratio gear like a worm gear to slow down the motion, and an on/off switch.

    How much motion you could get depends on the size and shape of the thing and how it is supported, so without a drawing it's hard to make any more comments.

    EDIT: In case it's not obvious to new readers of ths thread, I posted this before seeing the pictures.
    Last edited: Jan 24, 2007
  4. Jan 24, 2007 #3


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    I would suggest placing the battery and motor in one arm of the thing, connected by a drum cam or other reversing linkage to an equal weight in the other arm. Moving the weight farther in or out on the linkage will alter the centre of gravity and cause a rocking movement.
  5. Jan 24, 2007 #4


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    Another idea would be to use a linear actuator (e.g. a solenoid) inside the object, to move a weight suddenly between two positions. That would give you a rocking motion which would die away slowly after each move. If the electrical circuit flipped the weight back and forth at a suitable frequency, the motion could be quite complex and unpredictable - in fact, chaotic, in the mathematical sense of the word.
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