Fairly simple to make- here are the inexpensive supplies needed to make a few of these motors.
AA batteries have a diameter of 14.5 mm, so a bottom magnet with a diameter of 15 mm is just right:
From eBay: BUY NOW Neodymium Disk Magnet
Wire that looks and works well is just 10 gauge ground wire. Inexpensive and available at any local hardware store-- or order a small quantity here:
From eBay: BUY NOW 10 gauge Copper Wire
Wikipedia has some good details on the physics of homopolar motors
Homopolar Motor: a minimalist electric motor- battery, wire, and magnet. This type of motor does not need a commutator- the polarity of the electromagnetic coil does not need to reverse. The challenge with this design is balancing the coil to center on the battery as it rotates. A favorite DIY physics toy!
The kit includes the UV LED base, elegant glass sphere, and enough fluorescent gel for many repeat lights shows.
From PyroFarms: BUY NOW: FluoroSphere
From Amazon: BUY NOW: FluoroSphere
The FluoroSphere: intricate and dynamic lights shows are produced within an elegant glass sphere as fluorescent dyes in mineral oil slowly mix into room temperature water. Ultraviolet LEDs (in the base on which the sphere rests) make the dyes glow brightly and reveal the initial nondiffusive mixing structure which includes the phenomena of drops, plumes, and other features of Rayleigh-Taylor instabilities. Shown here, slightly sped up, is the first 8 minutes or so of the process which takes up to half an hour to mix evenly. The green light is characteristic of the famous fluorescein dye.
A DIY kit by the makers of Lava Lamp, home experimentation set with booklet of ideas to try:
From Amazon: BUY NOW: Lava Lamp LED Vortex kit
From eBay: BUY NOW: Lava Lamp LED Vortex kit
Vortex Lamp: a simple whirlpool powered by a magnetic stirrer like those in a chemistry lab and lit by LEDs. A DIY kit by Lava Lamp brand- which comes with glitter and beads, but I found the water vortex alone was mesmerizing to watch. Note the intricately changing structure of the vortex in the slow motion close up.
Guage block sets can be a bit pricy, but some fairly inexpensive pieces and small sets can be found for demonstrations and such:
From Amazon: BUY NOW: Gauge Blocks
Wikipedia has a nice description of Gauge Blocks and the Phenomenon of Wringing
Wringing Gauge Blocks: two blocks of metal (not magnets!) will stick together by a process called wringing if their surfaces are flat to high precision- such as these gauge blocks found in most machine shops. Here two blocks are forced apart with a snap, and then wrung back together with the characteristic sliding motion technique. Gauge blocks are flat to less that one millionth of a meter and are used by machinists for precision length measurements and calibration. The science of the wring force remains somewhat a mystery and no one has yet found a fully excepted physics description- but we do know that blocks will wring in a vacuum and that the force can be up to 30 times that of weight of the blocks. Fun physics from the shop!
This DIY magneits sculpture can be assemebled with these parts. Bring a magnet into a craft shop to find some necklace chain that is non-magnetic.
From Amazon/eBay: BUY NOW: Quilting Hoop, Neodyumium Sphere Magnets
Magnetic Suspension Sculpture: two neodymium magnets on chains suspended by their mutual magnetic attraction in this prototype kinetic sculpture. These powerful magnets hold the chains taut with about a 2cm gap. Made from a quilting hoop where the magnets connect under their own force to steel nails soldered on to non-magnetic chain.
Here is the NdFeB neodymium magnet used in this video:
From Amazon: BUY NOW: Neodymium Disk Magnet
Please use cuation when handeling strong magnets like this one. Small nails, paperclips, staples and other houlshold object made with iron will interact interestingly with the magnetic feild.
Ferromagnetic Interaction: iron rich nails temporarily become dipole magnets in the presence of an intense magnetic field from a large neodymium super magnet. Here the neodymium disk magnet is set with its north pole pointing up, so the point of each nail becomes a south pole (repelling each other) and the head of each a north pole. Imbued with these temporary induced fields, the nails will try to align themselves with the neodymium dipole’s field like compass needles, and the nails will interact with each other in interesting ways.
This "iBall" desk toy is no longer in producltion. Howerver, a similar version of this toy can be made from these components:
From Amazon: BUY NOW: two piece acrylic shell
From Amazon: BUY NOW: 1/4 inch ball bearings
Centripetal Kinetic Toy: seven rolling steel balls hug to the inside of the acrylic sphere given sufficient velocity. Here the balls are launched such that their orbits are in the same plane, and due to their angular momentum (and a torque due to gravity) the plane of rotation precesses like the axis of a spinning top until friction slows them down. This toy was made in 2007 (sadly no longer in production) and marketed under the name "iBall".
If you want to make one of these you will need:
1) some pyrolytic graphite (which can easily be sliced and carved):
From eBay: BUY NOW Pyrolytic Graphite
2) some neodymium magnets: the racetrack magnets are a bit pricey though!
From eBay: BUY NOW Diamagnetic Levitation Kit
3) shrink and print this image on medium weight paper,
and 4) cut and assemble!
Micro-Hoverboard: diamagnetic levitation technology- although Marty McFly would have to be three inches tall to ride this hoverboard. Made from printed paper and pyrolytic graphite with concentric circular neodymium magnet array. The magnetic rings alternate between north and south magnetic poles in just the right way to trap this special type of graphite. Pyrolytic graphite has strong diamagnetic properties such that it develops an opposite (but weak)magnetic field when in the presence of a magnetic field from another source. Swipe to see the graphite pieces levitating individually.
This inexpensive kit available here:
From Amazon: BUY NOW: Hyperbolic Holes Kit
Hyperbolic Holes: a straight rod, in this case a pencil, glides through a symmetrical pair of curved holes. The design is based on the hyperboloid, the 3D ruled surface traced by an offset rotating diagonal line. This device is sold as an inexpensive kit to assemble yourself, and includes a motor with geared drive and pre-cut pieces. The pencil is my addition- sharpened to just the right size to clear the curved openings.
Gallimum metal and a silicone mold to produce the spoon- available here:
From Amazon: BUY NOW: Gallium Mold Spoon Kit
Disappearing Spoon: the metal gallium has a melting point of 30°C (86°F) and will melt quickly when exposed to tea temperature hot water- or melt in one’s hand if handled too long. This spoon was made with a silicone mold (swipe to see process), and feels and sounds just like a regular spoon, except solid gallium is brittle and the spoon can shatter like glass if dropped. An amazing parlor trick as well as a classic and historical class demonstration.
For this demonstration stronger magnets work best:
From Amazon: BUY NOW: Neodymium Magnets
Here is a good small turntable with bearings:
From Amazon: BUY NOW: Spinning Base
Magnetic Influence on Aluminum: physics puzzler- spin a magnet under a beer can suspended by a thread, and the can will turn. Why? Aluminum is not ferromagnetic, and as shown, magnets are not attracted to the can. So how does a spinning magnet influence the can to spin?
Answer: the can spins due to eddy currents induced in the conducting aluminum due to the moving magnetic fields underneath. The eddy currents make the can into a temporary electromagnet that then interacts with the magnets below according to the famous law by Lenz.
Neodymium magnets will produce the largest gap when suspending a nail or other iron rich objects.
Please use exterme caution when handling these magnets.
From Amazon: BUY NOW: Neodymium Super Magnet
In Defiance of Gravity: a 3 oz plumb bob in suspension between a chain and a powerful neodymium magnet. Ferromagnetic attraction over a distance of many millimeters, and a reminder of the presence of the typically invisible electromagnetic forces all around us. Sculpture: oak, stainless steel chain and hardware, neodymium super magnet, standard plumb bob tool. Iron filings in oil align and chain together to reveal the magnetic field lines of the equilibrium configuration.
Get an affordable pre-bent light pipe demo here:
From Amazon: BUY NOW: Light Pipe Demo
Blue laser pointers (445nm) available here:
From eBay: BUY NOW: Blue Laser
but any color laser will work.
Make your own abstract light pipe sculpture, an inexpesive heat gun is the only needed tool:
Materials from eBay: BUY NOW: Acrylic Rod
Tool from Amazon: BUY NOW: Heat Gun
Light Pipe Sculpture: internal reflection constrains most of the laser light to propagate along the bent acrylic rod- the physics of fiber optics. This abstract sculpture was created by applying a heat gun to a 3/8” diameter acrylic rod. The laser pointer used here is blue at a wavelength of 445nm.
Click this link for a gyroscope that will perform the same trick!
Spinner Fidget Trick: defy gravity!- a trick to try with a fidget spinner you might have in a drawer somewhere. For the trick to work the spinner needs to have most of its mass far from the center (not all spinners will work)- and you may need to drill a hole down its center to attach an axle. This Spinpal spinner has three heavy steel spheres placed to maximize rotational inertia, that along with precision bearings, gives this fidget toy properties of a quality gyroscope. Give the spinner significant RPMs and it will suspend from, and precess around, a string! Thanks to @spinpal for sending me this a while back.
Amazingly this motor is available for less than $10 US.
From Amazon: BUY NOW: Brushless Motor/Generator with LED
Electric Motor/Generator: this inexpensive and common motor can also serve as a generator of AC electricity- here lightning an LED when the shaft of the rotor is spun by hand. Most electrical energy we use today is produced by moving a magnet near a coil of wire (known as Faraday’s law of induction) to produce an electric current. Removing the permanent magnet casing reveals this design to use 9 separate copper windings. I made a transparent second rotor with six neodymium magnets- and when these magnets are made to move near the windings the LED again lights with the flow of current. Swipe to see the beautiful magnetic field pattern of the rotor design using magneview film.
Get these 99.9% pure element Bi 83 cubes here:
From Luciteria: BUY NOW: Bismuth Element Cube
Many combinations of strong neodymium magnets will work, here are the versions I used:
From Amazon: BUY NOW: Cylindrical Neodymium Magnet
From eBay: BUY NOW: Tiny Neodymium Cube Magnets
See my video of other pure element cubes by Luciteria Science
Bismuth Diamagnetic Levitation: Element 83 (bismuth) is the most diamagnetic of the elements*. Here a small neodymium magnet is made to float between two 99% pure bismuth 10mm cubes which are held in precise configuration by friction with the parallel walls of the acrylic assembly I made. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the tiny cube magnet supplies the field. Diamagnetic fields are pretty weak though so a powerful cylindrical neodymium magnet sits above the cubes and is adjusted to help lift the tiny cube magnet against gravity. *except for a special form of carbon known as pyrolytic graphite.
This DIY project is pretty easy to build. One half of one of these inexpensive magnetic necklace clasps will work well for the heated magnet.
From Amazon: BUY NOW: magnets for curie point engine
A full engine is available from my friends at Grand Illusions Ltd:
From GI LTD: BUY NOW: Curie Engine
Curie Point Heat Engine: when the magnet on the end of the wire heats up to a particular temperature (the Curie point) its magnetic field is temporarily lost until it cools. This engine design uses a second magnet to pull the swinging magnet back into the heat source once the magnetic field is reestablished. Repetition of this process creates mechanical motion as long as the heat source is fueled.