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(c)2004 William Beaty

Also see: Fun with supermagnet beads

1.5" supermagnet sphere
Uncle Al <UncleAl0@> wrote in message news: <40475AB2.E5643DD@>...
> Why would one fabricate a rare earth dipole magnet as sphere?

No earthly reason. But many years ago the guys at had some tiny spheres made up.

They sold well even at a few dollars each. You can form them into little chains. (We resellers could play with vast arrays of them, but that was too expensive for anyone else.) Then they started selling 1/2 inch spheres, then large 3/4 inch supermagnet spheres.

A discovery: safe spheres. While two cylindrical 0.75" supermagnets, if they slam together, will grab the edges of finger tips and leave blood blisters, the spheres do not. Spheres tend to push the flesh out of the way as they come together. Also, spheres will rarely crack or chip, while two crashing cylinders will spall off little chips which travel at eye-piercing velocity. Sometimes the cylinder magnets even shatter on impact. The spheres never shatter (not so far as I've experienced, and I have lots them here.)

more videos ,    also physics collection

So now an unskilled adult can play with the larger supermagnets without experiencing blood loss or sudden violent pain. Don't worry, it still takes plenty of skill to handle the 1.5" spheres. Even the experts have scars and stitches. DANGER: Don't leave them out on your desk, or you'll be performing some inadvertent Natural Selection upon curious passersby. Plus erasing all their credit card stripes. At work I leave my largest ones stuck to a big nitrogen cylinder chained to the wall. Some people can't even figure out how to pull them loose.

Then the guy at started selling 3/8" supermagnet beads at very low quantity prices (like $.30 each.)

more videos

The things are VERY COOL in quantity. Long chains of them act like biology: rings will merge or peel apart like bacterial plasmids. You can spiral the chains up to make spiral-phase nanotubes or tobacco mosaic viruses. Make a ring-triangle of 3 beads, then roll a 4th towards it. The ring eats the bead, becoming a square. Chemical reaction? Molecular self-assembly? Roll a 5th in, and the ring snaps it up, becoming a pentagon. Add another, and sometimes it just sticks to the outside. The surface energy of your 2D molecule is too low. It needs to be highly stressed. So make a long linear chain, stick an extra magnet beac to the side, then pull on the chain. The chain eats the bead, becoming longer.

Take 60 beads, make twelve rings of 5 magnets each, then carefully merge them into a pseudo-buckyball ('pseudo' because they have4 bonds per atom instead of three, with squares instead of hexagons!) Note that the sense/antisense polarity of the pentagons cannot be ignored (so you can make "chiral" buckyballs, some with CW polarity, some with CCW.) Some supplier needs to make some beads with quadrupole magnetization rather than dipole, so a *true* buckyball can easily be made. (You can still make a true buckyball using 60 steel balls with lots of short supermagnet rods connecting them. But it's a big pain when compared to a buckyball made all of spheres.)

After a couple of hours I was able to simulate a buckyball origin: make two hemispheres of 30 magnets each, which when brought together will suddenly knit up into the 'buckyball' shape and entrap any ions which happen to get between 'em. Always wondered how that occurred.

The girlfriend now has chains of alternating gold and black beads. Play with dipole chain pseudo-biomolecules, then hide them as jewlery, as a spiral-wrap bracelet. (Hmmm. Reassemble the bracelet with black and gold Morse Code patterns for the well dressed amateur radio nerd?!!)

> It's a great price for the big one! The obvious thing to do is to order
> two and see how the pair is shipped. Kinda hard to envision a "keeper"
> to lessen field decay/time.

Put them in a thick styrofoam box. The fields at the box surface are low. Then wrap the box in thin iron sheets. The iron doesn't saturate. Or, if you bought a bunch of the things, they can be shipped formed into a ring where the field is internal to the ring and only 'leakage' fields escape. A single enormous magnet is harder to ship. Two of them can be rotated oppositely to mostly eliminate the distant dipole field.

Next: Fun with supermagnet beads > >



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