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[papakapp]

so, yeah.  I can't figure out what is going on here.  I am hoping that somebody a little more educated in this field can explain where the energy is coming from to spin the little thingy in the middle.

http://www.youtube.com/watch?v=hkgyY47duCM&feature=related

so, the guy adds some energy initially by pressing the ring down onto the center thingy.  Then I suppose some additional energy could be coming from slight movements in the guys hand while he is trying to hold the ring steady but I can't really put my finger on what is at work here.  I also don't quite understand exactly how he constructed the it.

[Dale Mahalko]

The top half of this is basically a magnetic repulsion bearing. The ring repels the magnet on the table, which is sitting on a spherical steel ball bearing.

What gets this going is the unevenness of the field of the upper ring. If all the upper magnets are oriented to repel the bottom magnet, since there is a gap in the magnets on the top ring, it is a weak spot in the upper field, and bottom magnet will initially tilt towards the weak spot.



(Yellow striped area is the region of repulsion between the upper blue field and the lower red field. The field is conical so the bottom magnet doesn't wander outside the repulsion field.)



Holding the upper ring perfectly level over the magnet below is hard, and the gap in the upper ring makes it hard to keep the bottom magnet perfectly level and stable.

If the bottom magnet and bearing could stand perfectly upright, it would not move. However, this will almost never happen because the magnet dips to the side, which results in an angular contact between the sphere and the table. It can now begin to "walk" the ball bearing across the table surface, which causes the magnet on the bearing to begin to rotate.



This shows a straight travel path, but this is only possible if the magnet stays at the same sideways angle. The axis is going to wobble, which continuously changes the angle of contact with the table, so it will seem to "walk" randomly.

The angle of contact between the bearing and the table is very close to vertical, so it spins fairly fast without moving very far. Eventually the rotor wanders too close to the edge of the table or your hand gets tired holding the ring, so the experiment stops.

You can probably "chase" the ball bearing all over the table if you carefully control the angle of tipping of the suspended ring.



Place the ball bearing centered on three other ball bearings glued to a platform, to form a very low-friction tripod, and it won't spin. It will stay upright due to the magnet repulsion, and maybe wobble, but not much more, because the well of the tripod doesn't allow wandering like on a table surface.

No "free energy" here, alas.

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