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Picture of How to Build a Magnetic Levitating Top
Nope, no Photoshop and no fishing line were used to make this picture, just 100% pure physics and some patience. This instructable explains how you can build your own top hovering in the air like a UFO.
 
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Step 1: Video Overview

Picture of Video Overview
Some steps of this instructable are difficult to explain with plain text or even show with static pictures, so I encourage you to also check this video illustrating the build and tuning process. Sometimes it is better to see once than read a hundred times.


Step 2: Earnshaw's Theorem

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Did you ever try to levitate a magnet with the help of bunch of other magnets? It seems very easy: since magnets can repel each other you probably can put a bunch of magnets in circle so they equally push the other magnet towards the center of the system. Or maybe even build a sphere made of magnets that would suspend another magnet in the center. But if that’s so easy why it is so difficult to build trains that use magnetic levitation? If you try these “easy” methods you will find they all do not work. In fact back in 1842 British mathematician Samuel Earnshaw proved that it is in fact impossible to suspend a regular magnet in space with the sole help of other regular magnets statically placed around it. Well he didn’t prove exactly that, but this follows from his original theorem. The proof of the theorem contains too many Greek letters to explain it in this short instructable, so let’s just trust those smart guys who triple checked it and found it correct.

So it is impossible to suspend a magnet in space using just bunch of other magnets. But take a look at the video. There is a large ring ceramic magnet and another magnet which is also a top. And if I carefully spin the second magnet above the first one it will indeed hang in the air. How is that possible?! Let’s talk about this and a few other loopholes in the Earnshaw’s Theorem and actually build a few magnetic levitation devices. This is gonna be cool!

Step 3: Bill of Materials

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It is actually very easy to build this levitating top. Below you can find the exact bill of materials I used. You can use it as a reference to replicate exactly my configuration:

* The large magnet is actually a stack of two 115x45x20mm magnets: http://www.magnet4sale.com/ceramic-magnets-ring/
* The small magnet is taken from a 1.42″ cup magnet. To take a ceramic magnet from the cup I put it in hot water for 20 minutes to loosen the glue, then pried with a screw driver and pulled out like it is shown in the video and explained further in this instructable step #6.

In addition to that I used

* 6.56mm (1/4″) wood dowel from Michaels
* Bunch of rubber and brass (i.e. non-magnetic) washers from Home Depot (Lowes has better selection of rubber washers, Home Depot has more brass ones). In fact for this exact setup I used only one washer with 32mm in diameter and 1.3mm in thickness. All other brass washers were not necessary in the final version.
* Plastic container from your cupboard to cover the large magnet. I used a 68mm tall and 143mm in diameter container #12 (1.5pt) from Rubbermaid.
* Aluminum or plastic (i.e. non-magnetic) sheet from Lowes
* Good electric tape

All in all this setup cost me approximately $30.

Step 4: Plastic Container?! Seriously?!!

Picture of Plastic Container?! Seriously?!!
The plastic container is required to protect the magnets from each other. No matter how careful you are the top will keep falling down and eventually hitting the magnet. Each time this is happening small sharp chips will fall off the magnets. Besides covering your work place with potentially dangerous to electronics magnetic dust they also ruin all your efforts to fine-tune the top. You don’t want that and the best way to prevent it is by covering the large magnet with a plastic container.


Step 5: The Height Does Matter

Picture of The Height Does Matter
Another function of the plastic container is to adjust the distance between the top and the large magnet. As you can see in the video this distance is very critical for successful initial spinning. The top of the container (plus the sheet) should be very close to the position where the large magnet stops repelling the top and starts attracting it. In fact you can even move the small magnet along the top stem to calibrate this distance precisely. If you try to spin the top on top of properly adjusted container it will actually stabilize itself for 5-6 seconds and spin absolutely straight.

Step 6: Retrieving the Smaller Magnet

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The smaller magnet I’ve got was inside a steel cup. In order to extract the magnet from the cup I soaked it in hot water for approximately 20 minutes, then used a screwdriver to pry and remove the magnet.

Step 7: Make the Top

Picture of Make the Top
weighing-the-top.png
Use the dowel to turn the small disk magnet into a top. I cut approximately 32mm off the dowel and polished one end with sanding paper to give it something like parabolic shape and make it smoother.

If you’re exactly following the specifications from rtfms.com add the rubber washer to make its weight approximately 12.5 grams. Make sure you put a non-magnetic spacer between the top and the scale, otherwise metal parts of the scale will attract the magnet and the measured weight will be inaccurate. See the video for details.


Step 8: Make the Base

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Since I'm using two smaller magnets for the base instead of one large this is the step where I stack them. Do not just put one on top of another -- you will damage both the magnets and your fingers. Instead, slide the top magnet on top of the other one. If that doesn’t work and magnets repel each other then flip one of the magnets and repeat the attempt. You can skip this step if you have one large magnet.

Cover the large magnet with the container, put the aluminum sheet on top and your base is ready.

Step 9: Adjust the Orientation and Height of the Base

Picture of Adjust the Orientation and Height of the Base
Now is the time for a few steps with a lot of text and no pictures. It's just really difficult to explain dynamic problems with static text, so check the video in step #1 to see how this works.

Put a flat sheet made of non-magnetic material on top of the plastic container and try spinning the top. Good chance it won’t not only levitate but spin as well. Several things could be wrong with it:

* The big magnet is placed upside down. Remove the cover and slowly lower the top on it. If, while lowering the top, you won’t feel anything then it you feel like the top is sitting on a magnetic pillow then it’s the wrong side. Flip the large magnet over. Now the top feels some resistance while you’re lowering it, than the big magnet starts pulling it inside the hole. That’s the right orientation. Put the cover back.
* The top is too high above the big magnet, so big magnet repels it and once you spin it it will fly away instantly. Reduce the distance from the top to the large magnet by lifting the large magnet. Washers and bottle cups will help you to lift the large magnet.
* The top is too low above the big magnet, so big magnet attracts the top too much and gyroscopic force is not enough to keep it straight. In this case it falls and tumbles immediately after you release it. You need to increase the distance between the top and the magnet. You can do it by lifting the plastic container on washers of bottle cups, for instance.

The perfect position for the top is slightly below that point when big magnet stops repelling the top and starts attracting. Adjust the height of the magnet under the plastic container so the top is located exactly at this position when you try to spin it. You can also move the small magnet alone the top stem to fine-tune the setup.
Please note that in this position you might need to push the top down slightly while spinning it. If you find this inconvenient feel free to reduce the distance between the magnets a bit more.

In fact one more thing can go wrong with spinning: the speed.

* If you spin the top too slow it will start precessing too much and fall too quickly
* If you spin the top too fast it will start precessing even faster and fall too.
* Spin the top not too fast and not too slow. In fact start from the slow side and keep increasing the speed until you reach the maximum speed after which the top goes crazy.

Besides just the initial spinning the spin-stabilized magnetic levitation only works at speeds between 1000 and 3000 RPM (revolutions per minute). So spinning the top faster than 3000RPM won’t help to keep it flying longer.

Once you positioned the top properly it should be able to spin stably on sheet. In fact if you are lucky and patient you can position it in a point at which it will self-stabilize itself. Even if you spin it not too well it will will eventually straighten up.

Oh, and one more important thing is where you start spinning - it should happen exactly above the center of the large magnet, otherwise the small magnet will tumble and not spin at all.

Step 10:

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It’s time to start phase two: coarse tuning. Slowly and steadily lift the sheet up maintaining the level. Several things could happen:

* Once you lifted the sheet a bit the top jumps and flies away. This means that the top is too light and gravitation force is not enough to compensate the magnetic repulsion force. Add some weight to the top. Brass washers are the heaviest ones, rubber ones are lighter. You can also sand the washers to adjust their weight.
* You keep lifting the sheet but the top never takes off the sheet. The top is too heavy and magnetic repulsion force is not enough to compensate the gravitation. Remove a washer from the top. If this is the last washer then replace it with the lighter one. If the top won’t take off even without washers at all you will need a stronger set of magnets.

After adding and removing washers to the top you should reach a point when the top takes off the sheet, tries to levitate on top of the magnet but after half a second it flies away. If you notice that it always flies in the same direction, then it’s time for phase 3: leveling.

* The reason the top is flying away always in the same direction is because the magnetic field of the large magnet is net perfectly level. Pretty much like a ball rolls down the hill our top rolls down the magnetic hill. You even can’t make it horizontal with a regular level as the big magnet could be unevenly magnetized. You need to keep adjusting the big magnet level until the top starts flying away in different directions. Also make sure that the big magnet resides on a firm surface like a table. Carpet won’t work as you will need to relevel the magnet too frequently.

The truth is you probably will need to do phase 2 and 3 simultaneously as it it sometimes unclear why the top flies away so fast. It could be both the magnetic field level and the weight.
Again, you can put washers or something else thick and preferrably non-magnetic underneath the large magnet in order to level it. You can even use an Arduino as a shim if you want to involve a microcontroller in this project :)

Step 11: Adjust the Weight

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At this point almost everything is working great except the top is still unable to levitate as it flies away. Time for the phase 4: final fine-tuning.

* Keep adding the weight of the top. You need to add small weights to the top. The fine adjustment weights are in fact so small that washers do not work anymore. We’re talking about 0.1g (0.004oz) precision. The best candidate for adjusting the weight is electric tape. Keep sticking small pieces of electric tape until the top stops flying away.
* If at some point top levitates for a few seconds than falls down -- take out a strip, cut it in half and stick one half back.

Using electric tape you can build a top that will levitate for a minute or two. One problem with it is bad aerodynamics of tape strips. Once you figured out the final weight it is probably a good idea to replace the take with a bunch of brass washers. This will increase the flight time to up to 5 minutes (well, 2-3 minutes is a more realistic time).

One more important thing is that the entire top should be very firm. No pieces should be unsecured or wobbly. Use crazy glue if necessary, but make it feel like a one solid piece.

Step 12: Amaze Your Friends!

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If you complete all this fine-tuning madness it’s time to call your friends quickly and amaze them. Do it quickly! The problem is that the effect is very unstable. Once the temperature in the room changes -- you will need to redu fine tuning. Humidity changed? Same thing. Someone put scissors nearby? Adjust it again. Or move the scissors away, whatever is easier :)

The fact this type of magnetic levitation is so unstable greatly reduces its usability. Basically besides amazing people you can’t do much with it. In the future instructables I'll explain how to build more practical levitation devices, so vote, follow, like, subscribe and keep DIYing!

If you like this Instructable please check my other instructables. Thank you for reading and watching!

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thanks :)

erich57 months ago

can someone help me do this with only two magnets

heey ... can i use a normal metal and Magnetizes with an electric current ? as i want the electromagnetic theory to be a factor here ..

what are the Obstacles that would face me ?

RC179 months ago
I was searching for this trick for a year.
JeyabargaviG10 months ago

Hello ... WOnderful instructables. I'd like to know if the same can work with shoes? Can anyone make this? I'm not much into science but love experimenting such things. Levitation has been my favourite subject and fantasies me a lot. I was super excited to see HUVRBOARD has built this technology, but disappointed as they are not giving any info on selling such boards (atleast for now). Could you possibly make this technology in shoes and other accessories? Could you kindly teach a layman like me how to build it sitting at home (required materials)?

ychoudhury1 year ago

Hi mikhalchuk.That was a great instructable.You have helped me a lot through this.

This is probably going to be a weird question but is it possible to add a bit more complexity to it so as to differentiate it from the rest.You see I have a science fair coming up and i had decided to exhibit this loop hole in Earnshaw's theorem but one of the other students overheard my team discussing it and now they too are doing the same thing.

Anyways I really like your instructable and your explanation was suburb.Pls keep up the good work.

samkashou1 year ago
Great work. Thanks.
bobsquared1 year ago
Hook it up to the bottom of my state board...
i wanted to levitate something easily and found it here! thanks!
jmc3cz2 years ago
Can u use magnets different from what you used?
Hi, could you comment on Tom Shannon's magnetic sculpture relative to Earnshaw's theorem?
It stays in the air with static magnets and does not move.
You can see it on the video at 02:00.

http://www.youtube.com/watch?v=OPA-rQyKeLY
Jussi, he clearly says he has it "down to one tether", it is not static with magnets alone, you can see the tether in this picture: http://i.imgur.com/GYfwY2g.jpg or at 1:52 in the video as the focus is changing
i am just a beginner..i have a doubt..
will it work if i rotate the base magnet (the one below using motor or smthing) and leave the small (levitating magnet) stationary.. will the small magnet levitate??
javidj182 years ago
As you probably saw many times when playing with magnets, magnets push each other away if you try to bring together their like poles, for example, two north or two south poles. Similarly, the north pole of the external field will try to push away the “north poles” of magnetized atoms. The magnet used in magnetic levitation creates a very large magnetic field (about 100 to 1000 times larger than household magnets). In this field, all the atoms inside the frog act as very small magnets creating a field of about 2 Gauss .You may say that the frog is now built up of these tiny magnets all of which are repelled by the large magnet. The force, which is directed upwards, appears to be strong enough to compensate the force of gravity (directed downwards) that also acts on every single atom of the frog. So, the frog’s atoms do not feel any force at all and the frog floats as if it were in a spacecraft.To levitate something the size of a human being it requires more powerful magnet.

Source: http://thesecretsofscience.com/science-in-nature/magnetic-levitation/

aharner14 years ago
in soviet russia magnet repels you!
lol awesome video
mikhalchuk (author)  aharner14 years ago
aharner1, hard to believe but in the USA magnets also repel humans! :)

Human body is 60-70% water which is slightly diamagnetic. In theory human body even can levitate in strong enough magnetic field. In practice, though, it is not achievable with permanent magnets and mankind didn't build so strong electromagnet just yet.

There are electromagnets powerful enough to repel and levitate frogs and even mice.
http://www.ru.nl/hfml/research/levitation/diamagnetic/
http://www.youtube.com/watch?v=A1vyB-O5i6E
Awesome accent.
hali182 years ago
can we use any other magnets
AltonB3 years ago
Excellent instructable. I have been working on building a mechanical based clock utilizing magnetic energy in order to extend run times, as well as, general experiments. There is a lot more to magnetic energy than conventional science would have one believe. For every law of physics there IS a loophole -(remember - conventional science at one time said human flight was imppossible)- it simply takes a lot of time, effort, and energy to find it. I appreciate your very thourough explanation of the process you use and excellent instructions. Your command of the english language is very good. Keep up the good work and I intend to check out your other stuff.
Alton B.
mikhalchuk (author)  AltonB3 years ago
Thank you AltonB! I'll keep working on my English too :)
Tinmanmike3 years ago
A good source of strong donut magnets is a broken microwave. They all have two good magnets in them. Wrapping electrical tape around them makes them chip resistant and easier on your fingers.
mikhalchuk (author)  Tinmanmike3 years ago
Too bad my microwave is not broken yet :)
Thanks for the tape hint!
So, if the temperature dropped or the humidity changed it would fall?
mikhalchuk (author)  blinkyblinky3 years ago
Unfortunately yes. In a controlled environment + vacuum it can spin and levitate for days, but in regular room conditions the effect lasts for a few minutes only.
Trooper5553 years ago
Dude this is great! hope you do more.
mikhalchuk (author)  Trooper5553 years ago
Thanks Trooper555! I'm working on new stuff, hope to get it published soon.
ericCycles4 years ago
Do stacked magnets generate a stronger magnetic field than one magnet? If not, could you replace the second magnet with any magnetically neutral spacer, like a piece of styrofoam or wood?
mikhalchuk (author)  ericCycles4 years ago
ericCycles, they do. The resulting magnet is less than twice as strong, but definitely much stronger than just one.
The spacer is also there - that's the primary function of the plastic container.
If you were to force them against each other, that effect may be attained. But not if you allow them to go the direction they want.
mikhalchuk (author)  Glenn Burrow4 years ago
Glenn, you're right, thank you for the correction and clarification. BTW, for reference here are a few sources that claim the opposite (and they are wrong):

http://www.eng-tips.com/viewthread.cfm?qid=148854&page=17
http://answers.yahoo.com/question/index?qid=20100228121105AAGhoeS

To my best understanding in this particular case stacking the magnets changes the configuration of the magnetic field, makes it "more directional" and increases its strength alone the axis. So to the top it seems like the stacked magnet is more powerful that single one.

Could you please comment if this is a correct guess? Definitely with one magnet this particular top won't hover, but it does levitate on top of the stack.

Thanks alot!
Stacking magnets is not always a solution. If you chain them long enough they will self-node, and fall apart at those node points.

The only real problem with this project is that the top is balanced on a point of UNSTABLE EQUILIBRIUM, i.e., the forces that are balanced are all trying to pull the top out of the "sweet spot" whereas a pendulum is and example of STABLE equilibrium because the combined forces keep drawing it back to the point of stability.

It looks like fun to try out, but I don't want to destroy any of the decent speakers that I have...
do you have a picture/thread for this "pendulum"? I've been working on one and would be interested to see what other results look like...

cheers, tom
Letting the magnets go the way they want when stacking them makes the fields larger because of overlap but not stronger. but if put in a direction against their "wish" they have a stronger field.
Sorry, mikhalchuk, But that is not correct. The sides that contact each other cancel out. You end up with a magnet of the same strength but double the size.
mondeluz3 years ago
this system is used in alien space ships XD
for how long will this spin??
chaitanyak3 years ago
genius!
doomsdayltd4 years ago
i see what your doing, the magnetic field is holding the magnetic top in place. very simple thing with magnets but very neat.
mikhalchuk (author)  doomsdayltd4 years ago
doomsdayltd, yeap, it's magnetic field + gyroscopic effect + precession. Pretty complex and not very stable combination.
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