Magnetic Toys

Vertical Mendocino Motor

Get this device for a great price here:

From EngineDIY: BUY NOW: Vertical Mendocino Motor

Vertical Mendocino Motor: each face of solar cell is connected to a coil of copper wire. Spins fast and quite in a sunny window. As the rotor turns each solar cell takes a turn in the brightest light, which provides electric current to one of the coils which becomes a temporary electromagnet that pushes against the permanent magnet configuration in the center- propelling the rotor to rotate. The rotor assembly is nicely symmetric and balances on a sharp point for minimal friction. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA 

Diamagnetic Racetrack

Diamagnetic levitation kits are available here: the racetrack magnets are a bit pricey though! 
From eBay: BUY NOW Diamagnetic Levitation Kit 

Educational Innovations has this affordable starter kit: 
From Educational Innovations: BUY NOW Diamagnetic Levitation Kit 

Diamagnetic Racetrack: thin pyrolytic graphite sheets levitate above powerful magnets. A set of five concentric neodymium magnets, alternating N-S-N-S-N comprise the racetrack and form the trapping field. Diamagnetic substances develop temporary repulsive magnetic fields only when they are in the presence of a magnetic field from some other source. Graphite of this sort is the most diamagnetic substance known.

Lenz's Law

Get a similar kit here: 
From Educational Innovations: BUY NOW Eddy Current tubes

Get some magnetic viewing film here: 
From Educational Innovations: BUY NOW Magnetic Viewing Film 

Lenz's Law: a strong neodymium magnet falls slowly down a copper bus bar as though passing through a viscous liquid. Since magnetic fields pass through copper, magneview film reveals the location of the falling dipole magnet. Moving magnetic fields from the falling magnet produce electric currents in the copper. These currents then produce magnetic fields that have the opposite polarity to the initial field. So a falling magnet makes the copper pipe briefly into an electromagnet that repels the magnet. The rectangular copper “pipe” is from a water-cooled electromagnet power supply line, 1.5 x 2 in (4 x 5 cm) in cross-section, designed to supply a steady DC current of 5000 amps. This 15” long piece weighs in at 12 lbs and has a 1/2” diameter hole for coolIng water to flow down its center. From a decommissioned particle accelerator magnet. 


Electric Motor/Generator

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.

Colored Ferrofluid Display Cells

Available on Etsy: BUY NOW Motion Ferrofluid Sculpture 

Colored Ferrofluid Display Cells: spectacular metallic blue, gold, and black display cells by czferro - colloidal ferromagnetic liquids in a specially prepared water-alcohol suspension. Curious behavior results from the interplay between magnetic force and surface tension. The gold and blue coloring appears to be from a thin coating at the boundary between the ferrofluid and the suspension liquid. Still exploring the details of the coloring and the specific makeup of the clear suspension fluid - both trade secrets it seems. 

Magswitch

The smallest Magswitch in this product line, yet it can lift 17 lbs! The Magjig 60: 
From eBay: BUY NOW Magswitch 60 
From Amazon: BUY NOW Magswitch 60 

Magswitch: switchable permanent magnet- a twist of a knob turns on a magnetic field strong enough to lift this 5.2 kilogram (11 pound) chunk of railroad rail. Magnetic fields, when combined, can be either additive or subtractive. This Magswitch model, the Magjig 60, works by aligning and counter-aligning two strong neodymium dipole magnets within a field channeling ferromagnetic casing.


Ferromagnetic Elements

10mm cubes of 99.9% pure elemets available here: 

From Luciteria: BUY NOW: Pure Element Cube Samples

These cubes include a laser etching of the symbol and element name on each. 

The main 4 ferromagnetic elements are: Fe, Co, Ni, and Gd. 

Ferromagnetic Elements: which metals from the periodic table experience strong attraction towards a magnet? Here are seven samples- 1 cm cubes of 99% pure elements: Ti (titanium), Fe (iron), Co (cobalt), Ni (nickel), Cu (copper), Gd (gadolinium), and W (tungsten)- which of these metals are ferromagnetic? Swipe once to check your answer, swipe twice to see how some are more strongly ferromagnetic than others. Although magnets are familiar objects, the physics of ferromagnetism is very complex and is described by the quantum mechanics of intrinsic particle spin and the specific electron configurations of solids and molecules.

Magnetic Suspsension Sculpture

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 HoopNeodyumium 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.

Magnetic Sand Hourglass

Get one from these fine sources: 
From Educational Innovations: BUY NOW Magnetic Sand Timer 
From Amazon: BUY NOW Magnetic Hourglass 

Magnetic Sand Hourglass: ferromagnetic sand collects above a neodymium magnet in the wood base. Each particulate of ferromagnetic iron becomes a temporary dipole magnet in the presence of the magnetic field in the base. The tiny dipoles link up north ends to south ends, creating interesting patterns that reveal the magnetic field lines. 


Magnetic Top and Snake

Available in a variety of styles: 
From eBay: BUY NOW Magnetic Top and Snake 
From Amazon: BUY NOW Magnetic Top and Snake 

Magnetic Top and Snake: the magnetic tipped top stays on the perimeter of the steel snake, but since the top has much more mass, the snake moves the most, slithering to and fro. This vintage top and snake came as a give away toy for kids flying on Western Airlines- a kinetic art toy that has been around for decades and takes advantage of Newton's 3rd law and rotational kinetic energy.

Revolution

This vintage toy can sometimes be found on eBay. 
Quality models of the modern version of this physics toy are still available 
From Educational Innovations: BUY NOW Magnetic Levitator 
From Amazon: BUY NOW Magnetic Levitator 

Revolution: vintage 2D magnetic levitation- permanent magnets can only produce static equilibrium along two dimensions- here a glass mirror constrains the third dimension, and makes for a nice bearing surface for rotation. This item was sold in the 1990s in mall shops such as Natural Wonders. 

Ferrofluid Magnetic Tree Sculpture

Choose from black, blue, or gold ferrofluid: 
Available on Etsy: BUY NOW Nano Tree Ferrofluid Sculpture 

Ferrofluid Magnetic Tree Sculpture: the 'Nano Tree' by Concept Zero designs using gold colored ferrofluid which can be manipulated with a handheld magnet. The spiky structure is due to the balance between the forces from the focused magnetic fields (from a neodymium magnet in the base connected to an iron rich bolt) and the forces from liquid surface tension on the colloidal ferromagnetic liquid. 


Golden Ferrofluid

Available on Etsy: BUY NOW Gold Ferrofluid Cell 

Golden Ferrofluid: colloidal ferromagnetic liquid in a specially prepared water-alcohol suspension. Curious behavior results from the interplay between magnetic force and surface tension. I'm still investigating the gold coloring and the specific makeup of the clear suspension fluid- both trade secrets it seems. The gold color appears to be a thin coating at the boundary between the ferrofluid and the suspension liquid.

Butterfly Mendocino Motor

Get this elegant motor here:

From Etsy: BUY NOW: Butterfly Medocino Motor

Butterfly Mendocino Motor: the simplest (and very elegant) version of this motor with only two photovoltaic cells mounted with care to ensure precision balance. This motor will spin quietly to high RPMs on any sunlit windowsill. In this model made by Semyon Nazarov of SolarWindRU, each of the two photovoltaic solar cells is connected to a coil of copper wire under the opposing solar cell. When the rotor is lit from above the top solar cell provides electric current to the coil in the bottom position which becomes a temporary electromagnet that pushes against the permanent magnet in the base propelling the rotor to rotate. As the rotor turns, the coil that moves into the bottom position is likewise energized by the solar cell currently at the top- one can say the light commutates this motor. 2D magnetic levitation is provided by permanent magnets where an acrylic plate constrains the third dimension, and makes for a nice bearing surface for minimal friction. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA

Magneview Flim

Get some magnetic viewing film here: 
From Educational Innovations: BUY NOW Magnetic Viewing Film 

Magneview Flim: making the invisible visible and revealing the hidden physics of our everyday world. Microscopic cavities in this green film are filled with oil and tiny flakes of Nickel metal- like compass needles, the flakes align with the magnetic fields revealing the complexity of the north and south pole domains of these magnets. Two of the disk magnets have multiple north and south poles and look like gears with teeth- these are rotors from small motors. 


Ferromagnetic Interaction

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.

Chaotic magnetic Pendulum

These chaotic pendula are still available on eBay!

From eBay: BUY NOW: Krazy Leg Pendulum

Chick here for similar chaotic systems

Chaotic Magnet Pendulum: adding magnetic forces to gravity gives this pendulum chaotic motion- not random, but very sensitive to slight differences in initial launch conditions. Swipe to see a particular launch path that begins with a semi-stable orbit but then goes chaotic, captured with an attached LED and recorded with a slow shutter app. Arranging the dipoles magnets on the base leads to different patterns of motion- here white attracts and black repels. This vintage device is from the 1970s and was sold by the name “Krazy Leg” by Rathcon Inc.

Gravity Defying Nail and Magnet

Neodymium magnets will produce the largest gap when suspending a nail.
Please use exterme caution when handling these magnets. 

From Amazon: BUY NOW: Neodymium Super Magnet

Magnetic Defiance of Gravity: a nail suspended 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. Make your own with a paperclip, string, and a refrigerator magnet- or get a neodymium magnet and see how massive an object you can suspend in air.