WWA Info Exchange

OK, relevance to turning: Each year our turning club has a contest to see who can make a little spinning top to spin the longest. I got it in my head to investigate magnetic levitation:

https://www.youtube.com/watch?v=VylZJrep1MM

Has anyone successfully tried making something like this? Either I don't have the right kind of magnets or their not strong enough. I figure if/when I do succeed I'll walk away with top honors: No friction other than air resistance should lead the way for a goodly long spin!

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Nullum Gratuitum Prandium

Cheers - Dennis

You are going to need some SERIOUS magnets! First thing that comes to mind is rob them from some large speakers. Or some magnets from an industrial item.
Not to mention that the WOOD WORKING turners may cry foul. But as I always say "Rules are not to be broken but they can be bent quite a ways" .

Rog

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Dont badmouth no strangers, they just friends you aint met yet.

An ounce of responsibility is worth a pound of State and Federal laws.

I spent most of my money on woodworking
tools and beer, the rest I just wasted.

They're not to know! (grin)

I've been trying to find a source for stronger magnets but the ones suggested in one of the on line articles I found aren't available from the source listed.

Next stop, a car stereo place. Perhaps they've got some junk speakers I can get pretty cheap.

Thanks for the suggestions, Rog.

_________________
Nullum Gratuitum Prandium

Cheers - Dennis

K&J Magnetics: https://www.kjmagnetics.com/ Whatever you want from a few ounces to over 1000lbs

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I bring to life, I bring to death:
The spirit does but mean the breath:
I know no more. (Tennyson, In Memoriam)

Thanks for the link, Gene, however I need something around 4" across for the base magnet. Like one of those big ring magnets out of a big bass speaker. I have one but it doesn't appear strong enough. The examples in one of the how-to links advises two stacked one on top of the other. A much smaller one is part of the spinning top. That I got out of one of those magnetic clip thingies eg refer magnet.

Plan on raiding a local car audio install place directly.

_________________
Nullum Gratuitum Prandium

Cheers - Dennis

Dennis,

Try looking on Craigs List for old used house or vehicle base speakers. It wouldn't matter what shape they are in since you will be taking them apart. Even if the speaker doesn't work it won't matter, the magnet should be fine.

Some speakers I purchased a very long time ago . . . . . (1972!) have magnets about 5" in diameter.
Sorry, no they aren't for sale!

For the smaller magnet, use a rare-earth magnet. I've seen them at WoodCraft, Harbor Freight and other places.

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I'm supposed to respect my elders, but its getting more and more difficult for me to find any (elders that is!)

Al

Hadn't tho't of Craig's list, Al. Thanks for the idea.

Meanwhile I'm on the call list for if or when one of the local auto-audio installers has something for disposal.

In the examples I've seen on several DIY sites, the smaller magnet consists of nothing much more than one from a magnetic refer magnet paper clip kinda thing. I have one rather large - 3 1/2" dia - speaker magnet but it doesn't appear to be strong enough.

Still in the development stage ....

_________________
Nullum Gratuitum Prandium

Cheers - Dennis

This one is likely strong enough and big enough but not sure you would want to pay the price. http://www.kjmagnetics.com/proddetail.asp?prod=RZ0Y0X0

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supporter of
http://www.pensforcanadianpeacekeepers.com/

I love the idea Dennis, wish I could help

I have found that the length of time a top will spin is proportional to the density of the wood and mass at the outer rim. I have had very long times with Ipe tops. Ipe is full of silica and is hard on tools but the tops really spin a long time. As my boy said when I showed him one: "It might as well be glued to the table, it just sits there!" getting a steel BB centered and glued to the tip helps keep it centered.I tried to make larger ones with four lead balls and springs to push the balls in toward the center as the top slowed like an ice skater pulling in their arms to increase the speed but could not get them balanced.