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Magnetic Levetation? A Magnet Levitating between two Bismuth plates? Answered

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I am trying to make a magnet levitate between two bismuth plates that i made (picture 3,4,5 and 6). As you can see they are round discs about 7mm (millimeters) thick and 110 mm or 11cm (centimeters) in diameter. I bought two magnets; -the one I am trying to make levitate is 30mm (millimeters) in diameter, 10mm thick, and 22kg (kilograms) strong... -the other that is on top, the one that is pulling the magnet up is 30mm in diameter, 15mm thick and 23kg strong I put my two plates of bismuth so that there is about 25mm of space between them... Than I put in the 30mm x 10mm magnet that I want to levitate inside. The other magnet is located above the setup. I very slowly, ever so carefully start to lower the magnet. The magnet between the two bismuth plates starts to shake and at one point hits the top bismuth plate. I can't make it to levitate, either it is on the bottom plate or on the top. I tried to make the space between two bismuth plates smaller and larger, to lower the magnet by a very small amount...it didn't help... PROBLEM: I can't make it levitate, either it is on the bottom bismuth plate or on the top... WHY IS THIS? HOW CAN I FIX IT AND MAKE IT LEVITATE? Thank you for your help! -Stanislav A.K.A. Comodore

36 Replies

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guyfrom7up (author)2009-04-19

it's been a long time since I did something similar, maybe u need a purer bismuth? Maybe the disks arn't perfectly uniform, causing erratic behavior

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comodore (author)guyfrom7up2009-04-19

I bought 1,5Kg of the cleanest bismuth there is and that is 99,9% bismuth... Hmm... You think the shape has to do with it? Thanks!

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joopdoop1 (author)comodore2013-02-10

Totally agree with your suggestion.. Very nice post and good information here..Thanks for posting that.. http://med-sciences.com/

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jfehr67 (author)2011-08-30

A little late, but there's a kickstarter project I have going that makes this really simple. http://www.kickstarter.com/projects/jfehr/magnetic-levitation-sculpture

Everything you need is included, and its flexible enough that you can use your own higher powered magnets to try to get larger levitation gaps.

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Goodhart (author)jfehr672011-08-30

IIRC the book Gonzo Gadgets also has this project in it.

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jfehr67 (author)Goodhart2011-08-30

The one above or on my kickstarter project? Do you have a link or anything for it? I'm curious how similar they are cause I went through about 10 very different prototypes to get to this.

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Goodhart (author)jfehr672011-08-31

The one above, the original post. The levitating magnet between lithium slabs. I didn't have any prospects of getting the lithium, so I didn't pay a lot of attention to that project. As for the book Gonzo Gadgets, there are a lot of sources for it.     Pyrolytic graphite can also be used. 

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lemonie (author)2009-04-19

Can you explain why it should - what precedent are you trying to follow?

L

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kelseymh (author)lemonie2009-04-19

Hi, Lemonie. Bismuth is diamagnetic; the idea behind these levitators is that both plates tend to repel the field of the enclosed magnet, so it sits a point of equilibrium. Problems include the instability of that point, the balance between the magnet's weight vs. the repulsion, and so on.

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Kryptonite (author)kelseymh2009-08-28

Maybe if it was put vertical with another plate of bismuth along the bottom to get rid of gravity?

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yokozuna (author)2009-04-19

Short Answer: The levitation is very sensitive, and depends on the width between the bismuth disks, plus the strength and distance of the magnet(s). Try raising your upper magnet, my guess is that it's too close/strong.

More complete answer/tutorial:
http://sci-toys.com/scitoys/scitoys/magnets/suspension.html

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yokozuna (author)yokozuna2009-04-19

Another problem could be your bismuth is too far apart around the magnet. Also, it looks like your melted bismuth was cast on the inside of the pop can, when most people use the outside, but that shouldn't really matter as much.

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comodore (author)yokozuna2009-04-19

It wasn't cast inside a can, it was cast in a coffee pot... it is 12cm, a can has about 6-7cm or so... You think that the bismuths diameter has to do with the problem...why?

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Kryptonite (author)comodore2009-08-28

See? I know you had class.

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yokozuna (author)comodore2009-04-19

No, i'm just saying you would have used less bismuth that way. Diameter of the plates shouldn't matter, but try moving the disks closer together (the magnet should fill most of the space, leaving very little room to actually levitate, as in the picture). Re-reading the question you say that your magnet is 10 mm thick, I'm guessing your plates need to be 12-13 mm apart instead of 25.

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comodore (author)yokozuna2009-04-19

I made an assembly, a long screw that holds the upper magnet, I turn it ever so slowly and go basically half a millimeter a second and still I can't manage to make it levitate, either it is on the top plate or on the bottom... My guess it that the magnet between the two bismuth plates it to big...or the bismuth plates are to thin...that is just a guess...What do you think???

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ReCreate (author)2009-05-02

You got pictures of it floating and working. XD I just wanted to say that :P

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Goodhart (author)ReCreate2009-05-03

probably a stock picture though.

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ReCreate (author)Goodhart2009-05-03

Yeah...You really look like you ate sour lemon in your avatar,By the way...

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Goodhart (author)ReCreate2009-05-03

Hmm, I thought I looked like I was about to burst out laughing :-)

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ReCreate (author)Goodhart2009-05-03

In a way,it does,but it looks more of the sour lemon thing

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fwjs28 (author)ReCreate2009-05-08

i say a mixture...almost like hes crying tears because the lemon is so sour...

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fwjs28 (author)ReCreate2009-05-09

llamas? ....nonono...its definitely a baby chimpanzee...

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ReCreate (author)fwjs282009-05-25

Here we go with your nothing comments,this is getting lame,you put another "=" in there

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Plasmana (author)2009-04-21

The problem is the magnet that should be floating is being pulled down by gravity from Earth.

From what I read on project like this, people say the they have another strong magnet a few centermeters above the top bismuth plate to help pull the 'floating' magnet from the gravity effect.

If you get the distant between the 'floating' magnet and the top magnet, correct, then you should see the levetation effect between the bismuth plates.

I hope this clears some things up for you.

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Goodhart (author)2009-04-19

Would a third magnet make it any more stable? (one below as well as one on top)

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Goodhart (author)Goodhart2009-04-20

The magnets would, respectively be pulling in opposite directions then, but that may not make it any more stable nor easy to balance the forces...

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Kiteman (author)2009-04-19

I don't know, but I can suggest several ways to work towards an answer:

Bring your bismuth plates closer together - magnetic forces are significantly stronger close-up (notic how in both your photos, there is a tiny gap between the floating magnet and the bismuth).
Bring your top magnet closer.
Spin the magnet you want to float (spinning makes it a lot more stable - try gluing a tiny bead to the bottom of the magnet as a pivot).

As yokozuna said, check the scitoys page where you got the first photo.

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comodore (author)Kiteman2009-04-19

The problem is no matter how close/stronger or far/weaker the magnet/magnet force is I just can't make it levitate, either it is on the top bismuth plate or on the bottom... How can I make it spin...I can't get it of the plate? My guess is that maybe the magnet between the two plates it to big or either the bismuth plates are too tin... What do you think? Thank you!

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