Magnetic Toys

Feel Flux Loop

Available as a set, or individually (all come with the super powerful sphere magnet) here:

From feelflux.com: BUY NOW: Copper + Aluminum Feel Flux

Feel Flux Loop: original (copper) and the "Skill Flux" version (aluminum)- toys that use Lenz's Law to manipulate a very strong neodymium magnet. The magnet falls a bit faster through the aluminum even though the walls are thicker- Al is only about 60% as conductive as Cu- so it takes more material to induce the needed magnetic field using aluminum. Interestingly the Al tube is about half the mass of the Cu one, even though it is larger in volume.

STORY Clock

This very high-tech clock is also high end (more expensive than most items I feature), with excellent craftmaship and technology that is clearly hard to replicate so that it is only made by, and available from, the FLYTE team:

From Art of Play: BUY NOW: Story Clock

From FLYTE: BUY NOW: US & Global Sales Story Clock or in EU Story Clock

STORY Clock: a spherical magnet hovers one centimeter from the face of this amazing clock and orbits in a circle to indicate the time- for this video I selected an orbit period of 40 seconds to show off the motion. The orbit of the magnetic ball can be set to any period but also has default selectable presets to indicate the current hour, minute, or second. This kind of levitation uses a control system with adjustable electromagnet coils in a feedback loop with Hall effect sensors which allow for fine tuning of a magnetic field to precisely balance the pull of gravity. Amazing magnetic levitation physics demonstrated by clever engineering by the @flyte.se team, this clock will work lying flat or hung on a wall vertically!

Bismuth Diamagnetic Trap Levitation

See more of Ernie's amazing creations here in his Etsy shop Element83 
From Etsy: BUY NOW Magnetic Levitation Sculptures

Bismuth Diamagnetic Trap Levitation: neodymium cube magnet trapped between two pieces of strongly diamagnetic bismuth crystal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so two large ceramic magnets are placed on each side and adjusted to help lift the cube magnet against gravity. Trapped in equilibrium by these magnetic fields, the slightest air currents can send the cube magnet dancing. Another amazing creation by Ernie McElhannon.


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.

Eclipse

Click here to visit this amazing Etsy shop Element83 
Get a magnetic levitation sculpture here: 
From Etsy: BUY NOW Diamagnetic Levitation Sculptures 

Eclipse: A diamagnetic levitation sculpture by Element83. Cast from diamagnetic Bismuth, a golden spherical neodymium magnet levitates trapped in a tunnel within the metal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the sphere magnet supplies the field. Diamagnetic fields are pretty weak though so a powerful cube neodymium magnet sits above the tunnel and is adjusted to help lift the sphere magnet against gravity. Trapped in equilibrium by these fields, any other magnet brought near will change the balance. ?Another amazing creation by Ernie McElhannon. 

 

Iron Filings in Silicone Oil Suspension

Available from these fine sources: 

From Amazon: BUY NOW Magnetic Field Viewer Set (get the demo set)

Similar device here:
From Educational Innovations: BUY NOW Magnetic Field Viewer with Magnet 

Iron Filings in Silicone Oil Suspension ( Iron filing field detector ): visualizing the invisible- the magnetic field lines around a horseshoe magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link up and align like tiny compass needles to follow and reveal the magnetic field lines associated with the permanent magnet underneath. Viscous silicone oil temporarily keeps the iron particles suspended yet allows for rotation and repositioning under the influence of the magnetic field.

 


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. 

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 

The Levitron

Levitron Tops were produced in the 1990s and are out of production and getting harder to find. Some models are still available here: 
From eBay: BUY NOW 
Levitron Top 

The Levitron: spin stabilized magnetic levitation- will fly for about 3 minutes or more per launch. The spin rate of the magnetic top must be just right for flight, not too fast or too slow. Air resistance and dissipative interactions between the magnets gradually slow the spin rate and the top falls. Interestingly trapping the top requires precision - the weight of the top must be adjusted to within 1 gram to achieve equilibrium between the pull of gravity and the magnetic repulsion from the large donut shaped magnet in the wood base. Repost of my favorite physics toy in my collection.


Gauss Gun

Similar devices available: 
Gauss Rifle Kit  or this classroom version Magnetic Accelerator

Easy to make with these magnets:
From eBay: BUY NOW Magnets for Magnetic Cannon DIY and  Steel balls for Magnetic Cannon DIY

Gauss Gun: acceleration of steel balls through magnetic potential energy and cascading collisions. Four neodymium magnets provide the potential energy that is converted into significant kinetic energy of the end steel ball. The initial configuration has two steel balls on one side of each magnet- an incoming ball on the opposite side accelerates and impacts each magnet in turn sending each loosely connected second ball off with greater speed. 

spYke Ferrofluid Display Cell

Check out the Etsy page of CZFerro: imaginative and quality ferrofluid display cells 
On Etsy: BUY NOW Magnetic Fluid Sculptures 

spYke Ferrofluid Display Cell: another spectacular display cell by czferro featuring a colloidal ferromagnetic liquid in a specially prepared water-alcohol suspension. The orange background highlights the curious spiking behavior of the black ferrofluid- a result of the interplay between magnetic force and surface tension between the liquids. 

Self-Propelled Homopolar Motor on Aluminum Foil Racetrack

I used neodymium disk magnets, small end = 1/2" diameter, Large end = 3/4" diameter. 
From eBay: BUY NOW Disk Magnets for Simple Motor 

Foil Runner Motor assembly diagram: 
Self-Propelled Homopolar Motor on Aluminum Foil Racetrack: A favorite DIY physics toy where disk shaped neodymium magnets supply the static magnetic field for this motor and become the wheels of a very simple vehicle with an AAA battery as the energy source. As soon as both ends make contact with the conducting aluminium foil an electric current will flow which in turn induces a magnetic field underneath the battery assembly. This induced field will then interact with the neodymium magnets on each end causing them to spin- a wonderful example of a motor with minimal components. The racetrack is a cardboard circle from a pizza box covered in kitchen foil.


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. 

Chaotic magnetic Pendulum

These chaotic pendula are still available on eBay!

From eBay: BUY NOW: Krazy Leg Pendulum

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.

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.


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. 

Paperclip Magnetic Top

These tops will work with a paperclip too: 
From Amazon: BUY NOW Magnetic Tipped Top 
From eBay: BUY NOW  Magnetic Tipped Top

Paperclip Magnetic Top: the magnetic tipped top attaches to the perimeter of the paperclip- but since the top has much more mass, the paperclip is put into curious motion due to Newton's 3rd law and the top's rotational inertia. This transparent version allows full view of the moving clip. Patented in 1946 under the name Hoy-Poy Top, this antique kinetic art toy made it into my collection as a gift from the folks at @shirepostmint- thanks! 

Magnetic Newton's Cradle

This magnetic version fo Newton's cradle is no lomnger in production, but somtimes found on ebay:
From eBay: Search NOW: Magnetic Newon's Cradle

Here are some nice versions of the classic Newton's Cradle 
and here is a nice Magnetic Replusion Demonstration

Magnetic Newton's Cradle: the famous collision demonstration reimagined with opposing magnets as the pendulum weights- shown here in two modes of operation. Initially the collision pattern looks similar to the traditional colliding spheres version but quickly goes chaotic- the magnetic field of each weight interacts with all the other magnets simultaneously making the system nonlinear. A 1990s desk toy by Fascinations- sadly no longer in production.