How does a square shaped magnet act like a ring magnet?

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1. Feb 17, 2016

ardakaraca

Hi, I'm working with a magnetic levitron project and I've borrowed a professional levitron to see how it works. When I remove the back cap, unexpectedly I saw a square shaped magnet instead of ring magnet. But it acts like almost a ring magnet. I'll explain the difference with images below.

At first image green labels show the reactions of another ceramic magnet when magnet located like 2nd and 3rd image.(When the levitron is flipped like 2nd,3rd and 4th images middle section attracts and the sides repels)

At 2nd and 3rd images, middle section attracts and the sides repels.

At 4th image, middle section repels and the sides attracts.

Finally my question is how the base magnet(1st image) polarized?(I mean what is the difference between regular square shaped ceramic magnet and that one?)

http://ardaka.com/img/1.jpg [Broken]

http://ardaka.com/img/IMG_0744.JPG [Broken] http://ardaka.com/img/IMG_0745.JPG [Broken] http://ardaka.com/img/IMG_0746.JPG [Broken]

Last edited by a moderator: May 7, 2017
2. Feb 22, 2016

Greg Bernhardt

Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

3. Feb 23, 2016

Staff: Mentor

For a commercial product, you want the magnet arrangement to be very stable. No matter how the magnets look internally, putting them in a square block is a good way to fix them.

You can check the average density. NdFeB magnets (and I guess you have those, but the values are not that different for other iron-based magnets) have a density of roughly 7.5 g/cm3. Is the average density of your block significantly lower?

There is no magnet configuration that would be stable against all possible motions of the magnets, so the arrangement guarantees stability against lateral motion only. Tilting is suppressed via the rotation of the magnet.