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Semi-Subsistant Gyroscope Torque

  1. Oct 22, 2003 #1
    Most of us have played around with gyroscopes, but I think that I have taken it beyond just "playing". I have come to notice that when a gyroscope begins to lose RPM, the top starts wobbling and procedes to spin in wider and wider circles until it clunks to the surface that it is placed upon. Having knowledge that there exist such gyroscopes that have bearings so efficient that they can continue to spin for years (Electrostatic Gyroscopes), I have an interesting concept. What would happen if you got the gyroscope to the velocity where it wobbles, and harnessed the energy of the torque caused by the wobble? Would the generator stop the wobble by producing electricity, leaving the gyroscope askew and preventing any more production? Would the wobbling cause a decrease in RPM, making this more difficult? If it is possible to continually juice juice from a wobbling gyroscope, then with highly-efficient bearings, wouldn't it at the very least be perpetual motion?
     
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  3. Oct 23, 2003 #2

    HallsofIvy

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    If you use this to generate electricity (or use the energy in any way) you are removing energy from the gyroscope- yes, this will cause the "wobble" ("precession" is the technical term). In fact it will stop the gyroscope itself! You can't get something for nothing.
     
  4. Oct 24, 2003 #3
    I believe that you think that I am referring to the actual rotation of the gyroscope itself when I am talking about harnessing its torque. This is not the case. Rather, leaving the rotation of the circular disc of the gyroscope alone, the machine would generate electricity from the spinning motion caused by gravity gyrating the gyroscope in a circular action. At its low RPM, the gyroscope would turn a generator from its axle at one end of the gyroscope's pole. The torque would be provided by its low RPM gravity-induced gyration.
     
  5. Oct 24, 2003 #4

    HallsofIvy

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    Energy is energy. You take energy out of the system, however you do it, the system is going to stop.
     
  6. Oct 25, 2003 #5
    It is removing energy from the system, but it is replaced by gravity-induced gyration, which is always present and contributing to the system.
     
  7. Oct 26, 2003 #6

    enigma

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    Again: If you take energy out of the system, it's going to stop.

    Gravity is not adding energy to the system. The wobble appears as a result of the dynamics of the rotating system; not as a result of gravity 'powering' the system up in any way.

    TANSTAAFL

    There ain't no such thing as a free lunch.
     
  8. Oct 26, 2003 #7
    A well constructed gyroscope that is equally balanced would not wobble in zero gravity; the fact that it rotates at low RPM under the influence of gravity shows that the gravity causes it to gyrate. Adding gravity to that gyroscope would be no different than adding downforce to the top with your finger. Considering that gravity consumes no energy, it is an efficient way to gyrate a gyroscope. You are right by stating that the gravity does not power up the system; the gyration is the gyroscope's reaction to the gravity. This brings up an interesting point. Gyroscopes appear to be non-Newtonian. There is no reaction to Centrifugal Force and the reaction to putting force on a gyroscope is not equal and is not opposite.
     
  9. Oct 26, 2003 #8

    Integral

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    This conversation has reached a point where the only response that can be given is.

    Built it.

    If you can make it work you will be a very wealthy man. But NO I will not finance your endevor.
     
  10. Oct 26, 2003 #9

    Integral

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    Definition

    Fool, One who thinks he is thinking outside the box. When in reality he has no idea where the sides of the box are and is lost in a dusty corner with blinders on.
     
  11. Oct 26, 2003 #10

    enigma

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    Gyroscopes appear to be non-Newtonian only to those who haven't studied their Newtonian equations of motion.

    Might I suggest Analytical Dynamics by Haim Baruh. He has an entire chapter devoted to gyroscopic motion.
     
  12. Oct 27, 2003 #11

    LURCH

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    It is true that taking power from the gyroscope will dampen the precession. What has been left out is the fact that this dampening will, in turn, cause resistance against the rotation, I think that's why Ivy said :

    However, one other step has been left out: the amount of energy you could get from such a system could never be as much as the amount it took to get the gyro spinning up to its operating speed (whatever that is) in the first place.
     
    Last edited: Jan 11, 2004
  13. Jan 11, 2004 #12
    Interesting topic. I have read about precssion and it was caused by the gravity acted as a torque to the original angular mometum. This torque will change the direction of angular momentum continuously. My question is it seems to me that when the gravity acting as a torque to the gyroscope. The gravity will no longer exercise weight to the bottom of the gyroscope. I might be wrong.

    An easy experiment can be done to verify this. Weight a gyroscope first. Rotate the gyroscope, put it on a scale and check how much it weight now. wobble it and check it again.

    Does any one know of any experiments done for that?
     
  14. Jan 11, 2004 #13
    Yes, Sammywu, i did an experiment with a gyroscope. I built a sturdy torque device designed to mount a gyroscope and rotate it about one of its poles at an angle. The premise of this was to test the machine in reverse. Namely, if down-force causes torque, then will opposite torque create up-force, or thrust? I turned on the electric motor, and holding the machine steady to keep the unbalanced weight of the gyroscope from shaking the machine off the scale, noticed that the weight did not change at all. This puzzles me as it is comparable to being able to turn a generator to make electicity, but not being able to put electricity through the generator to create torque.
     
  15. Jan 14, 2004 #14
    Futobingoro, I really do not think a torque or an angular mometum will generate any true forces along the vector's direction. I believe that should be only for convenience of calculation. My friend believes that and always argues with me.

    I think while the top or gyroscope wobbles, especially a top, part of the gravity will be lost used as the torque. It's like an orbiting object and stay afloat in the mid space without support.

    Not sure I am right. And not bothered with an experiment so I tried to find out anyone did it. Your thinkings as using gravity as a force to continue generating energy is very interesting even though it seems to violate energy conservation.

    There mudt be somewhere we do not understand something. Good luck.
     
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