Uses for super strong neodymium magnets?

June 2, 2005 5:43 AM

After seeing them used on MythBusters, I purchased a number of super strong neodymium 'rare earth' magnets. My legitimate practical reasons for using them have run out. Suggestions?

The reason I bought them, was because I had been looking for non-destructive ways to secure things on the backshelf of my car. A box of tissues, a rubber duckie, that kind of stuff.

Magnets seemed a good idea, (one in/on the item, the other on the underside of the shelf, holding it) but until I came across these neodym magnets, not even very large regular ones were strong enough to bridge the (half inch or so) gap of combined material and also hold the item and itself up.

Not knowing the strength beforehand, I ordered a selection of magnets, and now have a collection of magnets ranging in size and strength from 2x2x2mm (400 grams, ca. 1/2lbs), thru 12x3mm (4kgs, ca. 9lbs), to 35x12mm (50kgs, ca. 100lbs, (! for something only about 1.38inch*.45inch in size)). These weight-indications are what a *single* magnet fastened optimally to iron can carry, so you can imagine if you bring two of the stronger magnets together, you are in serious trouble. It does mean however, that two tiny disks can safely secure a rubber duckie on your car's backshelf.

What other uses could these crazily strong things have? Creativity is encouraged. Animal cruelty is not.

posted by Grensgeval to Technology (19 answers total)

Wipe the credit cards of people you know and dislike. Use them to hang pictures on thin walls. Hang things on your windows. Pesky cabinet door won't stay shut? No longer! Use them as bookmarks, doorstops, or can holders. Need more counter space in your kitchen? Use a pair to lift that bulky toaster oven up out of the way!

Neodymium magnets: is there anything they can't do?
posted by staresbynight at 6:28 AM on June 2, 2005

If you have a bike, you could make a clipless rack to hang your bike on at home. My bike's frame is aluminium, so I'd have to fit some steel inside the frame, somehow, to do this, but it'd be plenty cool.
posted by veedubya at 6:43 AM on June 2, 2005

I've literally got hundreds of those things. They're just so cool.

I don't know if you've done any experiments yet, but here's a simple but cool one.

Get a length of copper tube that's slightly larger in diameter than one of your round magnets. Hold the tube perpindicular to the ground, drop the magnet down it. The magnet will slowly drift down the length of the tube.

Copper's not magnetic but the falling magnet induces a current through the pipe which in turn induces a magnetic field that opposes the magnet so you end up with magnetic braking.

The best demo I have of this is on the huge heat sync from the first Sony CD player. It's aluminum and one of my smaller disc magnets fits between the fins. When I drop it through it just sort of oozes down.
posted by substrate at 6:43 AM on June 2, 2005

I don't remember if they used neodymium magnets, as I was too excited to read the article closely enough, but in the first issue of MAKE (check your local massive bookstore - it might still be on the shelf in the computer section) they showed how to make a model railgun with magnets and stainless steel balls. Sadly I'm at work and can't tell you more than it was reeeeaaally cool...
posted by Moondoggie at 6:48 AM on June 2, 2005

Gauss gun.
posted by cgs06 at 6:51 AM on June 2, 2005

Give yourself superpowers or at least security scanner sensing powers.
posted by phearlez at 9:22 AM on June 2, 2005

Attach them to a drill for cheap-ass television degaussing.
posted by shepd at 9:24 AM on June 2, 2005

These look pretty neat. Found this "Fun with Magnets" page.
posted by Carbolic at 9:31 AM on June 2, 2005

Yeah cgs06 - that's the one I was thinking of in MAKE/01. Sweeet
posted by Moondoggie at 9:31 AM on June 2, 2005

Some BDSM people apply a pair of strong magnets to pinch naughty bits.
posted by matildaben at 10:22 AM on June 2, 2005

Try playing with some of this with your magnets.
posted by jimmereeno at 10:45 AM on June 2, 2005

Tie a 5'-10' piece of string to a paper clip, and the other end to a fixed point. Then stretch out the the string so that the paper clip is near the magnet, which will hold the paper clip in place and the string taut.

Not very useful, but maybe you could precess a light gyroscope on the string, and that would be cool...
posted by LordSludge at 11:24 AM on June 2, 2005

you can use them to open high security locks. unfortunately i can't find the video now. anyone else know what i'm talking about? it might have been a boingboing link.
posted by andrew cooke at 12:12 PM on June 2, 2005

Sounds fun, what's the best place to order the magnets?
posted by dirtylittlemonkey at 12:31 PM on June 2, 2005

Could I attach the roof rack to my car with magnets? That would be pretty cool.

Hard drives have a strong magnet inside. If you have dead drives; they're fun to remove. They'll ruin the paint on the fridge, so be careful.
posted by theora55 at 2:05 PM on June 2, 2005

dlm: Lee Valley Tools carries them; there's also a big magnet distributor on the web. Getting them via mail may be a challenge, though, as they tend to destroy things around them (ie. the postman's credit card, videocassettes, kittens).
posted by five fresh fish at 5:22 PM on June 2, 2005

You can purchase magnetically-mounted roof racks, yes.
posted by five fresh fish at 5:23 PM on June 2, 2005

Best answer: okay, number one, duh, ... Immortality

On a more realistic note, get yourself some ferrofluids and go nuts.
posted by nanojath at 6:50 PM on June 2, 2005

Response by poster: Wow, immortality. If there ever was a 'best answer' on MeFi, that is it!
posted by Grensgeval at 3:12 PM on June 3, 2005