Pyrolytic Graphite Levitation

Pyrolytic Graphite Levitation

Pyrolytic graphite is poly-crystalline graphite deposited at high temperatures by thermal decomposition (lysis) of a hydrocarbon. Basically they obliterate carbon (or some organic) with high heat and it deposits back down into honeycomb shaped sheets...or they blast methane in a near vacuum with high heat and it vapor deposits back down into a single layer of graphite that is highly ordered and build layer-up-layer, but can easily be separated. These sheets are diamagnetic: they push away from a magnet by creating an opposing magnetic field to the magnet’s field. So, what can you do with it? Levitation!

There are many experiments showing a magnet floating between two pieces of pyrolytic graphite with a much larger magnet overhead. What a boring waste: the opposing magnetic force the graphite creates is so tiny that it can’t lift the magnet…so they use a big magnet above to do the lifting and then the graphite bounces it up and down to center it in mid-air.

Here’s an easier idea: but a bunch of magnets on a table and then flop the graphite on top of them: instant hoverboard!

A neat little trick if you've got a bunch of pieces of pyrolitic graphite (which I do) is to split them sheet-wise with a knife to get two thinner sheets from a single thicker sheet. Anyone whose played with the mineral mica knows how to do this. Thinner and thinner also means lighter and lighter and thus easier to float higher and higher from the magnets.

The layered structure plane has strong covalent bonding but weak electrostatic bonds between planes which leads to a high degree of anisotropy (it’s various properties are directional: like it’s easier to crease cardboard in certain directions but not others, etc.). Thus, the magnetism is very perpendicular to the sheet (which is why is hovers away/up from magnets). 

Is pyrolytic graphite new? Nope. It's been studied in textbooks since at least 1960!

So, basically get four or more magnets and put them on a steel sheet so they don't slide around. For the first time ever I actually shattered a rare earth magnet by having it slide towards my 1" cube N52-strength magnets. It was amazing and annoying and spit tiny slivers of the non-magnetic chrome coating everywhere. 

A great way to handle these is to use wood handscrew clamps. They're for wood working. I clamp two magnets in two separate wooden handscrew clamps with the face of the cubes NOT extending past the front of the clamp. That way you can ease them together.

Also, I used a compass. The face that the North of the compass points to is south on the magnet. Obviously, where the south of the compass points is the north pole of the magnet. Yes, the poles of the Earth are mislabeled.

I needed to make a checkerboard pattern of north and south faces pointing up for my pyrolytic graphite levitation setup-although the height of levitation i achieved doesn't really grow with more powerful magnets.

If you get cylinder magnets you can make two columns side by side with the columns made of cylinders end to end. In the long trough between the two columns you can float a piece of 0.5mm mechanical pencil lead.

Gauss Gun

A Quick Gauss Gun Post

In a simple Gauss Gun a steel ball rolls toward a magnet with two balls on the opposite side of it.

The ball nears the magnet, which pulls on the ball and increases its speed.

The ball slams into the magnet, which transfers the energy and momentum of the ball to the first ball on the other side. The first ball transfers this energy and momentum to the second ball-which goes shooting off.

The last ball shoots off at a much faster speed than the original ball because of the increased acceleration provided by the magnet as it "grabbed" the original ball when they got close to each other.

The magnet with two balls on one side is a stage. You can set up many, many stages in a row to create a chain reaction with a pretty fast moving ball shooting out of the last stage.

Rolling friction, aerodynamics and the magnets pulling too hard on the secondary balls can steal some of the energy and momentum by not letting the last ball go easily to the next stage. A way to counteract that is to use electromagnets (coils) that shut off right as the stage receives the incoming ball.

I came up with an easier solution: have the first of the two balls be non-magnetic! It acts as an isolator between the magnet and the second ball that gets launched to the next stage.


Another thing that steals energy and momentum is if the magnet slides backwards a little to meet the incoming ball a little earlier. The solution: I taped the magnets down so they wouldn't move.

Experimenting with different sized ball bearings, different numbers of them and different strength magnets all have noticeable effects on performance. As do the spacing between stages.




Here's some simple performance test videos I made:

I found that K&J Magnets has some medium sized magnets and balls that work even better than larger ones. I had great results with the quarter inch (D44) ones:

K&J also have an awesome blog with tons of projects like this (which include links to their industrial products if used in the experiment). Very cool! 

K&J also explain the science behind Gauss guns (and magnets in general) without delving needlessly deep into Newton's Second Law of Motion, as most explanations online do. Hint if you read up elsewhere: a euclidean vector is just an annoyingly complex way of denoting an arrow. "The ball shoots that way!"

If you're interested, F=MA , Force equals Mass times Acceleration. You have to kick heavier balls harder to get them to go the same distance. What's important is that Acceleration here is just the initial jolt/kick, just like the better quick on/off electro-magnets in a coilgun! It sets the object in motion. That is all (and that is the best part). Newton's Third Law of Motion is the equal and opposite reaction one: which is why taping the magnets down is better: no jolting back and forth. The tape helps conserve energy.

Newton's First Law is just the one about inertia: objects at rest or in motion stay that way unless acted upon by unbalanced force. It's why the balls eventually stop instead of blasting a hole in the universe.

If you add a bunch of stages you might just get some cool results, but you might shatter a magnet or put a hole in something! Eyewear is a must! All the laws take their toll on the Gauss gun, especially a simple one like this.

However, at some point I'm going to try 20 stages firing .177 pellet gun bbs. I have a feeling their reduced mass (M) will insurmountably hinder optimal performance.

Carl Friedrich Gauss worked on a lot of number theory mathematics, but he also founded the "Magnetic Club" in 1883. He has a unit of measure (the gauss) named after him. It measures magnetic fields, and Gauss formulated ways to measure the properties of magnets using only the simple concepts of time, mass and length. Specifically, he came up with a better way of measuring the oscillation of a magnetized needle to measure magnetic field intensity. This used to be measured in a unit called the gauss, but they changed (in 1932) the term gauss to refer to electromagnetic induction, and field intensity was then notated in units called oersteds--Hans Christian Oersted discovered electromagnetism in 1820.

Magnets actually have different gauss values for their different fields (surface, residual flux) and all things being equal a physically larger magnet will have a lower surface field! So, magnets have various other ways of denoting their "strength". The easiest is pull force: how many pounds can it lift or pull?

Another is the N number, which is derived from a magnet's MGOe (Mega Gauss Oersted) value. Neodymium rare earth magnets range from N35 to N52. This is the amount of stored energy (energy density) in the magnet.

Speaking of energy, check out what else these magnets can do:

The magnets used in this post were all N42 magnets. The white part of the gun was just a piece of ceiling molding. Just scraps.

I need to borrow the Gauss gun just one more time, Meow!

Ferrofluid DIY

Fe2O3(Co) + (CH3)2CO = Fe2O3 (and fun)!

Magnetic ferrofluid is expensive, so I decided to make my own.

Heineken mini-keg: cut the top off using a lathe; put unspooled audio tapes, unspooled VHS tapes and acetone in it; covered with foil. This is now a ferrofluid delaminator.

Iron particles sloughed off of cassette tapes via acetone bath. A simple ferrofluid showing the spikes of the magnet below. Without the magnet the particles disperse into the acetone and just sort of tint the liquid.

Place a strong magnet at the outside bottom of the keg. Gravity and occasional shaking will send the nano particles of iron to the bottom.

Every day I'd stir the tape spaghetti before and after work. I did this quickly because acetone fumes are highly inflammable and headache inducing. I kept this project outside the house!


A powerful magnet is a must. I use 1" rare-earth neodymium magnets which are actually quite dangerous. Hold one in your hand and any piece of metal can fly right into/through your flesh! These chrome looking magnets can also shatter if allowed to slam into each other. Read the reviews on Amazon about them: they're not lying about blood blisters, stitches and broken fingers.

I once stuck a 1" cube rare-earth magnet on my refrigerator--and by "stuck" I mean I had to get a pair of pliers to take it off.

This is a 1" cube rate-earth magnet. It is sinking into my bed. Not because it's heavy, it is, but because it's trying to burrow through my mattress to get to the steel support springs! It also started making my digital camera glitch so I couldn't get too close to it: notice how the sheet is a warm color but around the magnet it's greyed-out? Supposedly strong magnets cannot harm digital cameras--but something sure sucked the color right out of the center of this photo, LOL.


What's cool is that if you get a really strong magnet and some regular, non-nano sized iron fillings in mineral oil you can get the same effect!

What you are seeing is the actual shape of the magnetic field.

An easier way to see it, but in two dimensions not three is to buy a cheap piece of magnetic field viewing film which is just plastic sheets with oil and iron particles sandwiched in between.