Magnetic Toys

Self-Propelled Homopolar Motor on Aluminum Foil Racetrack

I used neodymium disk magnets, small end = 1/2" diameter, Large end = 3/4" diameter. 
From Amazon: 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.

Lenz's Law with Feel Flux

Feel Flux-- available as a set, or individually (all come with the super powerful sphere magnet) here:

From BUY NOWCopper Feel Flux

Get some magnetic viewing film here: 

From Amazon: BUY NOW: Color Magnetic Viewing Film
From Educational Innovations: BUY NOW Regular Magnetic Viewing Film 

Lenz's Law: a strong Feel Flux neodymium magnet falls slowly down a thick walled copper tube as though passing through a viscous liquid. Since magnetic fields pass through copper, magneview film reveals the location of the falling dipole magnet. The moving magnetic field from the falling magnet produces 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 then repels the falling magnet. Swipe to see the magnetic viewing film in detail. Special thanks to the guys from Feel Flux who kindly sent me this awesome longer piece of the copper tube from which their amazing toy is produced. 

Levitating Mini Moon Lamp

Get this fun lamp here (comes with both Mini-Moon and silver sphere magnet):

From Amazon: BUY NOW: Levitation Lamp

Levitating Mini Moon Lamp: tapping the floating illuminated Moon turns this LED lamp off and on in this strange design. The Moon with embedded magnet floats a couple centimeters from the surface of the base when plugged in, and feels springy to the touch. Within the base is 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 on the tiny Moon.

Magnetic Suspension Lamp

Available for under $100 US: 

From eBay: BUY NOW 
Magnetic Suspension Lamp 
(Helical filament versions found here)

From Amazon: BUY NOW 
Magnetic Suspension Lamp 

Magnetic Suspension Lamp: not only does this lamp defy gravity, the LEDs in the bulb are powered through wireless induction (no batteries needed). This kind of levitation uses a control system with an adjustable electromagnet in a feedback loop with Hall effect sensors which allows for fine tuning of the magnetic field to exactly balance the pull of gravity. If this lamp design is unplugged (or the power goes off) the bulb assembly does not fall, but instead snaps onto the upper armature via strong permanent magnets embedded within. Amazing physics demonstrated by clever engineering! 


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 team, this clock will work lying flat or hung on a wall vertically!

Vertical Mendocino Motor

Get this device for a great price here:

From EngineDIY: BUY NOW: Vertical Mendocino Motor

From engineDIY: BUY NOW Horizontal Levitating Motor (on all models here-remove brown protective film to reveal clear acrylic on rotor)

Mendocino Motor: vertical and horizontal versions- each face of a solar cell is connected to a coil of copper wire across from the opposing solar cell. When the rotor is lit from one side the lit solar cell provides electric current to the coil in the opposite position which becomes a temporary electromagnet that pushes against the permanent magnets in the base propelling the rotor to rotate. As the rotor turns, the coil that moves into the position near the magnet is likewise energized by the solar cell currently at the top- one can say the light commutates this motor. Magnetic bearings to reduce friction in both models. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA 

Buda Ball

Only made by the Flyte team:

From Art of Play: Buda Ball 

Buda Ball: a spherical magnet is pinned 1.5 centimeters from the surface of its hardwood base. Within the base is an innovative 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- even when the base is in a vertical orientation! Amazing magnetic levitation physics demonstrated with aesthetic design (and very clever engineering) by the Flyte team- the only (non-superconducting) system I know of that can suspend in a horizontal direction as shown in this video. 

Magnetic Sand Hourglass

Get one from these fine sources: 
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. 

Thermomotor Curie Point Engine

Available in limited supplies here:

From Etsy: BUY NOW: Thermomotor Candle Engine

Thermomotor Carousel: this decorative and dynamic centerpiece is actually a Curie point heat engine! Two tea light candles continually chase two magnets around a magnetic ring in this truly unique design by @violet__revolution. When the portion of the magnetic ring over the flame heats up to a particular temperature (the Curie point) its magnetic field is temporarily lost until it cools, so the magnet near the candle is now pulled toward a cooler portion of the ring- which then heats up and the process continuously repeats creating the steady rotation. Swipe to see the full design (complete with a laser cut forest mantle) in operation. Many thanks to artist and inventor Darragh Hewat for this fantastic addition to my collection. 

Precision Machined Haptic Fidget

Get this device here:

From Etsy: BUY NOW: Precision Fidget Devices

Precision Machined Haptic Fidget: four identical stainless steel components precision manufactured to 15µm tolerances via wire EDM (electrical discharge machined) and embedded with magnets to produce a stepped locking mechanism for a haptic sensory experience. The rainbow finish is due to a very thin layer of oxidized titanium produced by a process called physical vapor deposition (PVD) where a molecule thin coating is created under vacuum. So much interesting physics in the many production methods used to make this everyday carry fidget. 

Iron Filing Field Detector

This device and similar ones available here: 

From Amazon: BUY NOW Magnetic Field Demonstrator Kits 

Iron Filing Field Detector: visualizing the invisible- the magnetic field lines around a dipole bar 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.

Tesla's Egg of Columbus

Get this amazing (and affordable) reproduction here:
From engineDIY: BUY NOW: Tesla's Egg of Columbus
This version comes with a 35mm solid aluminum sphere. 

Get the aluminum phiTOP "egg"  here: BUY NOW phiTOP 

Tesla’s Egg of Columbus: an aluminum ellipsoid egg (PhiTOP) mysteriously spins and stands upright in this modern version of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. The base has no moving parts- instead special copper windings (very similar to Tesla’s original design) form four electromagnet coils on a circular steel core, and a special circuit supplies each with AC currents in such a way that a rotating magnetic field is created. This rotating magnetic field from the coils under the concave glass induces electric eddy currents to flow in the aluminum ellipsoid- these currents then create their own magnetic field which oppose the initial fields underneath and pushes the ellipsoid to spin. Finally, the ellipsoid top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top. 



Magnetic Soma Cube

Get this inexpensive SomaCube here:

From Amazon: BUY NOW: Magnetic Soma Cube

Magnetic Soma Cube: a new fun variant of the famous math toy invented by Danish scientist and artist Piet Hein, who claimed that this puzzle came to him as he was listening to a lecture on Quantum Mechanics by Werner Heisenberg (yes- that Heisenberg). The seven pieces of this puzzle are all the ways 3 or 4 cubes can be joined such that the piece has at least one inside corner. In this version small magnets are encased in cleverly designed cavities such that they will always flip over to attract a counterpart in another puzzle piece, allowing the puzzle to stick together- or hang from the side of the refrigerator. Amazingly there are 240 ways to make the cube from these 7 pieces- still not that easy! 

Mag Flip Inverted Pendulum Fidget

Available from this fine vendor:

From Etsy: BUY NOW: Mag Flip Desk Toy

Mag Flip Inverted Pendulum Fidget: three embedded neodymium magnets provide tactile repulsive forces in this simple but intriguing system. Pressing down on one side increases the magnetic potential energy that will then send the pendulum into frantic motion until the kinetic energy is damped out after a series of oscillations. This fidget can also be used as a random coin flip with respect to which side it will land. 


Magnetic Chaotic Pendulum

Click here for similar magneitc pendulums you can buy. 

Get the magnetic viewing file here:
From Amazon: BUY NOW: Color Magnetic Viewing Film

Magnetic Chaotic Pendulum: this beautifully designed “perpetual pendulum” has been in my collection since 1990. The ufo shaped bob has a magnet embedded in it and the base has a battery and simple coil circuit that gives the bob a tiny push each time it swings through the center. An array of 5 permanent magnets are also hidden in the wood base (wait for reveal with magnetic viewing film) and these magnets produce the chaotic motion- not random, but very sensitive to slight differences in initial launch conditions. A clever design feature connects the pendulum to the top mount with yet another magnet, and this sharp contact point greatly reduces friction such that a fresh 9V battery in the base will keep the pendulum in motion for a couple months. 

Ferromagnetic Interaction

Here is the NdFeB neodymium magnet used in this video:

From Amazon: BUY NOW: Neodymium Disk Magnet

Please use extreme caution when handeling strong magnets like this one. Small nails, paperclips, staples and other houlshold object made with iron will interact interestingly with the magnetic field. 

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.

Magnetic Top & Spiral

Available from my friends at Grand Illusions Ltd.: 
From Grand Illusions: BUY NOW 
Magnetic Top with Spiral 

Also on Etsy: BUY NOW: Magnetic Top with Spiral

Magnetic Top & Spiral: the magnetized tip connects to a metal cutout in the shape of a spiral, but since the top is more massive, the spiral is the object that moves creating this curious motion. This kinetic art toy takes advantage of Newton’s 3rd law and rotational kinetic energy. 

Bismuth Maglev Rod

Get this amazing and affordable science sculptue here:

From Etsy: BUY NOW: Bismuth Maglev Rod

Click here to see other diamagnetic toys and scuptures 

Bismuth Maglev Rod: Small magnets are trapped, suspended and floating, within the notch of a rod cast from the diamagnetic metal bismuth. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the small floating magnet supplies the external field. Diamagnetic fields are pretty weak though, so a powerful neodymium magnet sits above the gap on the top of the rod, and its height is adjusted to help lift the small magnet against gravity. Another amazing creation by Ernie McElhannon of Element83.