Hi amp bearing motor

[tinman]

Most of us would have seen one befor,but how many know how it work's?. Some say the balls heat up on one side and deform the ball so as to create rotation-a push from the ball ,due to an oval shapeforming from heat on the ball's. Who knows why this isnt what is happening?,nor how it works.

http://www.youtube.com/watch?v=g60okBMeTKo

Would it work with AC,as well as DC?. One would have to say it would,as it rotates in both directions with DC-regardless of polarity.

Testing comeing soon.

And is it related to the workings of the homopolar motor?
http://www.youtube.com/watch?v=hXbFfMBW97A

[broli]

Yes it will work with AC and the "rotation due to expansion" is just a theory. Noone, as far as I know, replaced the bearings with discs and carbon brushes to show that it's not due the expansion/contraction of the ball bearings, my guess is that it even will work with brushes.

[TinselKoala]

I'm another one who can't quite buy the "thermal expansion" theory of why this motor operates. I don't have an alternative explanation, though.
I don't think it's a homopolar motor and I don't think that a disc-brush version would work, without making it a homopolar system by including a source of magnetic field in the right orientation. These are empirical questions though. (A true homopolar motor will "selfstart" but this system needs a nudge in either direction to start spinning.)

The problem with experimenting with this system is that it requires high currents, several tens or even hundreds of amperes, to operate, and whether AC or DC, these kinds of current levels can be dangerous and may be more than the table-top experimenter is able to handle easily and safely. The typical power source for this experiment, a car battery, can actually explode if any of several possible adverse events occur during this experiment.

[tinman]

I'm another one who can't quite buy the "thermal expansion" theory of why this motor operates. I don't have an alternative explanation, though.

This alone is reason it should be looked at some more-a challenge.
Maybe Poynt or MH would like to have a go at it?. But first we need a safe power supply that wont explode,and i think i have just such a supply.

I believe it dose work via produced magnetic field's-some how???.

[broli]

I'm another one who can't quite buy the "thermal expansion" theory of why this motor operates. I don't have an alternative explanation, though.
I don't think it's a homopolar motor and I don't think that a disc-brush version would work, without making it a homopolar system by including a source of magnetic field in the right orientation. These are empirical questions though. (A true homopolar motor will "selfstart" but this system needs a nudge in either direction to start spinning.)

The problem with experimenting with this system is that it requires high currents, several tens or even hundreds of amperes, to operate, and whether AC or DC, these kinds of current levels can be dangerous and may be more than the table-top experimenter is able to handle easily and safely. The typical power source for this experiment, a car battery, can actually explode if any of several possible adverse events occur during this experiment.

There is a paper out there that pretty much explains it and asks other interesting questions:

http://arxiv.org/ftp/physics/papers/0012/0012009.pdf

The fact you need to give it a nudge makes sense as well, you need a small circular component to create your "magnet". However in the paper the circular component is there by design thus the starting torque is not 0.