Magnetic Levitation Idea, tell me why this won't work
Magnetic Levitation Idea, tell me why this won't work
(OP)
Hello all! new here, first post, nice to meet ya. I've just had this idea in my head for a long time, and i've been wanting to make a real life model of it but i'm not entirely convinced that it'll even work, please help me to see whats wrong with this idea..i don't know how to post pics but i'll put links to them.
If you took a wooden sphere and drilled 1/4" deep holes with a spade bit all over the surface, each hole with a diameter the same diameter of the magnets to be used. And then superglued a magnet set into the hole one at a time in each hole, with the positive pole facing out.(or negative, but we'll just go with the positive for this) Assuming that the magnets were spaced out evenly over the whole sphere, and set 1/4" (or more if need be) deep into the wood, would you have a sphere that was completely surrounded with a positive magnetic force field? Bear with me... if that worked then couldn't you make a wooden rectangular box for a base and set magnets in it the same way as with the ball with the positive poles facing out and equally spaced, set into the wood and superglued down. when you placed the ball over the base, would the ball be able to "land"? i know it would probably try to jump off the base but then you could just build a fence to keep it from falling off the base. Assuming (and i'm sure i've already made an ass of myself) that this all worked, wouldn't you have a ball levitating over a base and perpetually spinning trying to either land or escape. i'm sure that i'm missing some basic mundane point here, or its already been done, so just go ahead and tell me where i messed up.. here are some crude drawings to help you see what i'm talking about if i was unclear, thanks for reading this and helping! Mark
http://www.geocities.com/markvaughn99/sphere.JPG
http://www.geocities.com/markvaughn99/base.JPG
http://www.geocities.com/markvaughn99/fence.JPG
http://www.geocities.com/markvaughn99/levitate.JPG
If you took a wooden sphere and drilled 1/4" deep holes with a spade bit all over the surface, each hole with a diameter the same diameter of the magnets to be used. And then superglued a magnet set into the hole one at a time in each hole, with the positive pole facing out.(or negative, but we'll just go with the positive for this) Assuming that the magnets were spaced out evenly over the whole sphere, and set 1/4" (or more if need be) deep into the wood, would you have a sphere that was completely surrounded with a positive magnetic force field? Bear with me... if that worked then couldn't you make a wooden rectangular box for a base and set magnets in it the same way as with the ball with the positive poles facing out and equally spaced, set into the wood and superglued down. when you placed the ball over the base, would the ball be able to "land"? i know it would probably try to jump off the base but then you could just build a fence to keep it from falling off the base. Assuming (and i'm sure i've already made an ass of myself) that this all worked, wouldn't you have a ball levitating over a base and perpetually spinning trying to either land or escape. i'm sure that i'm missing some basic mundane point here, or its already been done, so just go ahead and tell me where i messed up.. here are some crude drawings to help you see what i'm talking about if i was unclear, thanks for reading this and helping! Mark
http://www.geocities.com/markvaughn99/sphere.JPG
http://www.geocities.com/markvaughn99/base.JPG
http://www.geocities.com/markvaughn99/fence.JPG
http://www.geocities.com/markvaughn99/levitate.JPG





RE: Magnetic Levitation Idea, tell me why this won't work
There's nothing special in having magnets repel themselves, keeping objects from going into contact.
Also note that your ball will likely go towards a corner of the rectangular area and stay there, but this could depend on the detailed layout of the magnets.
prex
http://www.xcalcs.com
Online tools for structural design
RE: Magnetic Levitation Idea, tell me why this won't work
RE: Magnetic Levitation Idea, tell me why this won't work
http://www.o-keating.com/hsr/maglev.htm
ChemE, M.E. EIT
"The only constant in life is change." -Bruce Lee
RE: Magnetic Levitation Idea, tell me why this won't work
While you do have a clever idea, you're basically describing the prinicple behind maglev trains. Of course, maglev trains use an electromagnet repelling against a permanent magnet, but the idea is the same. The key thing is that the repelling magnet (in a maglev situation) is restrained from flipping over during repulsion.
One thing to keep in mind regarding your description of the magnetic field distribution around your sphere: No matter how evenly spaced the magnets are around the sphere, you will have an uneven distribution of magnetic field. It will be mostly positive (or negative, depending on whether you had all North or all South exposed), but there will be uneven fields between the magnets. That gradient will significantly reduce the repulsion force.
One other thing, for your base: You'd be better off just having one large rectangular magnet instead of an array of disc magnets. A bowl shaped base magnet will not help very much. As you mentioned, Earnshaw's theorem makes a compelling argument as to why two permanent magnets won't levitate stably unless one degree of motion is constrained.
There are novelty devices that exploit this phenomenon. I've seen pen holders and a top that use this effect. Last spring, I helped a schoolkid design a working model of a maglev train for a class project (he did the hard work, I just supplied the materials). It was quite a challenge to keep the train on the track.
RE: Magnetic Levitation Idea, tell me why this won't work
I hope this will help,
MAgnetic levitation, a long sought after dream when it comes to stability. There are some experimenters out there that have found - when building a levitation device - suspending one magnet above a magnetic base - by spinnig the magnetic base you acheive a form of stability. You may try this in your attempts.
Also, another possibility, try Diamagnetic Levitation. Unlike Ferromagnetism and paramagnetism, this is considerably more stable.
Consider the maglev train except using eddy current.
A magnetic field moving across say copper or aluminum producing eddy currents into the material. The eddy currents repel the field developed in the magnet (at sufficient speed). They are in fact opposing polarity to that which created them.
Just some ideas that may help.
You can find more on Diamagnetic Levitation at www.quad-tech.com
RHmagster
RE: Magnetic Levitation Idea, tell me why this won't work