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Possible to make your own magnetic gears?

  1. Nov 25, 2015 #1
    Is it possible? Could i cut a round peice of aluminum and stick magnets into it to resemble a spur gear? I am trying to make a 4:1 gear ratio but eliminate friction, i was thinking if i could custom fit magnets in the aluminum wheel (since magnets are not atrracted to aluminum). I would have both the bigger gear and smaller gear with the repel side. I was hoping i could make my own rather then going thru a big name company like magnomatics.

    Also would there be problems with the magnets spinning at high rpm? Around 40-50,000, the smaller gear would basically be free spinning so i dont see very much torque being apllied to any of the gears.

    Any suggestions?
  2. jcsd
  3. Nov 25, 2015 #2


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    Gold Member

    In principle: Yes.
    But the gear may easily be brought into oscillation, thereby being brought out of synchronism ( will skip a "tooth" ), because every manget is swinging in a magnetic field.
    If the gear is not oscillating, it's because it is dampened by eddy currents in the aluminum, that creates losses. So no friction losses but eddy current losses. The gear will be heated up, when spinning.

    The gear works like a synchronous motor, that will also oscillate if it is not carefully controlled.

    Anyway I will suggest the magnets to be mounted, so that they will attrack each other in pairs. I think that the amount of eddy currents will be smaller this way.
  4. Nov 25, 2015 #3
    Thanks for the reply! Did some reasearch on eddy currents and it all seems like jibberish to me. From what i took in is that it happens whenthe magnetic field changes within a non magnet item. I was considering using the repel side since i was told the repel side is much stronger with repel compared to the attract side. Also there would be a slight torque load on the gears. How would this double attration work? Would it be when the 2 teeth attract to eachother or when the two gears attract?
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