Experiments with magnets and our surroundings

Cool magnetic toys you can buy

Please note:  the information at the end of each article refers to the part number of that item at the source indicated.  Arbor is Arbor Scientific, ScientificsOnline is ScientificsOnline, AS&S is American Science and Surplus, EdIn is Educational Innovations.

Magnetic Marbles

These are plastic marbles or balls which have a magnet in them so that they will stick to one another.  You can make some interesting shapes with them.  They cost only about $4 for 20 marbles.
Arbor P8-1122, ScientificsOnline 34-968, AS&S , EdIn M-620

Mysterious Magnet Tube

This is a great device to help see magnetic fields.  It is a tube within a larger tube, containing iron filings.  Place a magnet inside the smaller tube and shake the filings around to see how they form on the magnet.  If you place another magnet inside, you'll see the opposing fields form.  This is a super toy!  It even comes with a real cow magnet.  From Dowling Magnets.  Cost is only about $12. 
Arbor , ScientificsOnline 52-976, AS&S , EdIn

Magnetic Field Viewer

This is another great device to help you see magnetic fields.  It is a thin film containing powdered iron  and a green oil.  Place the film onto a magnet and see where the poles are located and the line between the poles.  You can easily see the strips of N and S poles on the back of inexpensive refrigerator magnets!  The way it works, is that either a North pole or a South pole will appear very dark green, almost black.  The line which divides the North from the South poles appears very light green, almost white.  This way, you can see how many N and S dividing lines there are.  From Arbor Scientific.  Cost is only about $2.50.
Arbor P8-1152, ScientificsOnline 33-447, 37-906, AS&S , EdIn M-555

Iron Filing Case

This is similar to the mysterious magnet tube, but flat.  It is a thin plastic box with iron filings in it.  Place a magnet onto the surface of the box and see the fields appear.  The plastic box keeps the filings contained, which is real nice!  Cost is only about $2.  From American Science and Surplus. The third photo is similar but has pink sand mixed in with the iron filings.  Placing a magnet on it will allow you to separate the iron from the sand.  Also cost about $2, from Educational Innovations.
Arbor , ScientificsOnline , AS&S 91408, EdIn M-610, EdIn M-615

Magnetic Wands

These wands are popular items in several stores.  They are fairly strong and are great to demonstrate the attraction between unlike poles and the opposition between like poles.  They also work well to see what objects are attracted to magnets.  Cost is about $2-$3 each.  (Just don't get them close to the screen of a color TV!  You'll see more colors than you want, and they won't go away easily!)
Arbor P8-1165, ScientificsOnline , AS&S , EdIn M-510.

Here are some tips on how they interact with each other:

First photo is where they are attracted to each other, North to South.  The large flat faces are the strongest areas of the wand magnets.
Second photo is where they are repelled by each other, South to South.
Third photo is where both of their South poles are facing up, and they don't want to stick.  The sides are weaker than the faces.
Fourth photo is where red is South up and blue is North up, so they stick.

Fifth photo is like the third, both of their South poles are facing up, and they don't want to stick.  The ends are the weakest part of the magnet.
Sixth photo is like the fourth, red is South up and blue is North up, so they stick very weakly.
Seventh photo shows how a magnet can pick up a bar of steel.  It only works with the large flat face, not the sides nor the end.
Eighth photo shows how the wand magnet can be modified to be very strong on the end, easily picking up the bar of steel.  Just strap or tape or rubber band two pieces of steel onto the flat faces of the magnet.  This re-directs the magnetic flux to the end of the magnet where the steel bar is located.  The wand magnet is very strong this way!

Magnetic Sculptures

There are several types of magnetic sculptures where you have two strong permanent magnets in a base and shapes of iron pieces (temporary magnets) which stick to one another and the base.  You can form them into towers, bridges, etc. The one on the right is called Magnetic Magic from Carlisle Co (1-800-233-3931). 
Arbor , ScientificsOnline 81-985, AS&S , EdIn

Roger's Connection

This is a clever toy which uses magnets at each end of the black plastic tubes and steel balls to form various geometrical shapes.  The photo on the right shows how you can even magnetically suspend a structure and spin it.  From Roger's Connection.  Cost is about $36, but it is a well constructed kit of parts.
Arbor , ScientificsOnline , AS&S , EdIn

Geomag or Supermag

These kits are very similar to Roger's Connection.  The construction of the plastic connectors that hold the magnets is better than the other, but they are a lot shorter.  Nice thing is that the plastic connectors come in different colors and that there are two sizes of them.  Cost is still kind of high, but they are fun to play with.  They can be found in Zany Brainy and many other stores.  A couple of other sources are www.plastwoodusa.com and www.geomags.com.  A kit of 50 pieces, as shown here, (magnetic connectors plus steel balls) is about $22.
Arbor , ScientificsOnline, AS&S , EdIn

Make-Your-Own Sculptures

You can buy a bunch of magnets and steel balls and make your own sculptures!  Be creative!  I had these three steel balls, 1.875" diameter (and weigh 1 lb each), and some NIB magnets sitting around.  The grouping on the left is using magnets measuring 3/8" long, 1/2" dia, with a 1/4" hole in the center.  The grouping on the right is using magnets measuring 1/8" thick, 3/4" dia, with a 7/16" hole in the center.  I kind of like the one on the right more.  What I want to do next is buy a few more balls and magnets and add to it.  The balls cost about $3.25 each from AS&S.  Everybody at work likes to pick this up and see if they can pull the balls apart.  This is what I call a "heavy-duty" sculpture.  

If you want, here's a site that puts kits of magnets and balls together for you.  They have some great stuff at www.amazingmagnets.com.  These photos show some of the things I was able to do with their kits, like the superball and the 6 pointed star and some 3/4" balls and spherical magnets.  The superball I am holding is simply an icosahedron (20 equilateral triangles arranged in groups of 5, like the first photo in this grouping showing two of them) using fancy triangles.  I also made a buckyball (aka truncated icosahedron) and an icosidodecahedron.  Check out these other sites on the 5 Platonic and 13 Archimedean solids.  This is great fun!

http://www.scienceu.com/geometry/facts/solids/handson.html
http://www.scienceu.com/geometry/facts/solids/
http://mathworld.wolfram.com/ArchimedeanSolid.html
http://www.georgehart.com/virtual-polyhedra/archimedean-info.html
http://www.mcs.drexel.edu/~crorres/Archimedes/Solids/Pappus.html
http://www.ul.ie/~cahird/polyhedronmode/favorite.htm
http://www.intent.com/sg/polyhedra.html
http://www.intent.com/elysian/sgds.html

In order to plan for how many balls and magnets you will need, use this table for the cube, pyramid (like the square bottomed Egyptian pyramids), the tetrahedron (triangular bottomed pyramid) and the octahedron.  (The octahedron can be made by building a tetrahedron with an odd number of layers and truncating each of the four corners; or by building two pyramids, one larger than the other by one layer, and joining them back-to-back).  The number of layers refers to the number of balls along the edge of the shape.  

Here are the general formulas for these shapes, where "x" is the number of layers:

Cube:  (shown is a 2 layer and a 4 layer)
    number of balls = x³
    number of magnets = 3(x³-x²)

Pyramid:  (shown is a 2 layer and a 5 layer)
    number of balls = x(x+1)(2x+1)/6
    number of magnets = 2(x³-x²)

Tetrahedron:  (shown is a 2 layer and a 6 layer)
    number of balls = x(x+1)(x+2)/6
    number of magnets = (x³-x)

Octahedron:  (shown is a 2 layer and a 5 layer)
    number of balls = x(2x²+1)/3
    number of magnets = 2x(2x-1)(x-1)

Arbor , ScientificsOnline, AS&S , EdIn

Joe Bender

This is another fun toy which uses magnets on each hand and foot so that you can twist the poor fellow around and hang him from a hand or foot from any steel structure.  They come in all sorts of outfits and colors.  When you buy them, they are all folded up within the can shown in the photo on the left.  This was a freebie, but they usually cost about $10.  Available at www.toymagnets.com/desk_toys/index.cfm.
Arbor , ScientificsOnline , AS&S , EdIn

Magnetic Space Wheel

This toy has been around since the 1960's, maybe before!  It is a clever toy which uses a magnet as an axis for the wheel, keeping it in contact with the wire frame which acts as a track.  The wheel follows the track around on the inside and outside of the frame.  From Action Products International.  Cost is about $4
Arbor , ScientificsOnline 81-795, AS&S 91608, EdIn

Wizmo XT

This is the updated version of the space wheel, where XT means extra long.   There is even an "Executive" version, with a black handle and chrome wheel!  Cool!  Cost is about $10.
The photo on the right is called Wacky Wheel from Slinky.  Similar product, but uses a steel band instead of the two wire tracks.  The wheel rolls along the band which you can bend into wacky shapes.  Cost is about $5.
Arbor , ScientificsOnline , AS&S , EdIn

Spiraculum and Radiaculum 

Another, more artistic variation on the theme.  Clever and beautiful designs.  On the Spiraculum (the photo on the left) the wheel can roll on the outside of the spiral or between the center rod and the spiral.  On the Radiaculum, the top rolls along the curved wire.  Cost is about $45 each.  For a movie to see how they work, click on the photo.  Designed by Jochen Valett in Germany in the 1970s.
Arbor , ScientificsOnline , AS&S 91668, EdIn JV-200
Similar units called Explorer and Spiral Spinner from ScientificsOnline 82-285, 82-283

Orbitron

Another variation where the wheel rides on the outside of the wheel.  Cost is about $15.
Arbor , ScientificsOnline , AS&S , EdIn
A larger, similar unit called Revolution from ScientificsOnline 82-284

Magnetizer / Demagnetizer

Just pull your screwdriver through the center to magnetize it, or scrape it along the outside to demagnetize it.  Works well!  Inside the hole, you have a North pole on one side, and a North pole on the other side.  The fields are pushing against each other.  With the screwdriver in the hole, the fields concentrate in the steel and magnetize it.  To demagnetize, simply rub along the South pole that is on the outside of the cube.  Cost is about $4.
Arbor , ScientificsOnline 81-665, AS&S , EdIn

Horseshoe Magnet

A horseshoe magnet of Alnico, great for small experiments.  Please note the keeper on the end of the magnet - needed to help prevent the magnet from becoming demagnetized.  Cost is about $4.
Arbor , ScientificsOnline , AS&S , EdIn

Magnetic Pick-Up Tool

A very handy telescoping tool with a strong NIB magnet on the end.  Great for picking up something that may have fallen into a tight place.  Remember, if the walls of the tight place is steel, this won't help much.  Cost is about $5.
Arbor , ScientificsOnline , AS&S , EdIn

Magnetic Mysteries Set

This is a super kit of magnets, coins, magnetic viewing film, a ball bearing and steel plates!  It came with a very well written booklet full of interesting experiments.  This is a great buy from Arbor Scientific.  Cost is about $30.
Arbor P8-1155, ScientificsOnline , AS&S , EdIn

Magic Pennies

Another great kit with two magnets and several British one pence and two pence coins.  Great booklet with several experiments and tricks.  Cost is about $22.
Arbor , ScientificsOnline 81-463, AS&S , EdIn

Magnet Man

How about that?  A fridge magnet in the shape of a man which doubles as a clip!  From Ace Hardware.  Cost is about $2.
Arbor , ScientificsOnline , AS&S , EdIn

The Funny Thing Oscillator

This item is almost a one of a kind.  I was browsing through ScientificsOnline (Edmund) retail store in Barrington, NJ, when I came across this.  It is similar to the MagnaSwing, but is more versatile.  Essentially you have a coupled oscillator using the two arms made of spring steel.  The magnets on the arms affect the oscillation frequency, and also provide repulsion between them.  There is plenty of   physics involved here.  This is a copyrighted sculpture, 1997, by Funny Things, Ltd.  Cost is about $25.
Arbor , ScientificsOnline 81-401, AS&S , EdIn

Luna Balls

This has some clever experiments for you to try.  There are 4 balls, each a different size, each magnetized.  The way they interact is not always what you'd expect.  From ScientificsOnline.  Cost is about $2.
Arbor , ScientificsOnline 60-508, AS&S , EdIn

Hooks

These really aren't toys, but they sure are useful.  We had the hooks with the ferrite magnets in the base as shown in the upper right of the first photo.  Whenever we'd try to remove a utensil, the hook would pull off the side of the exhaust hood above the stove in the kitchen. Not only that, but the hook itself didn't fit the hole in the end of the utensil handle very well, either.  So, I finally got smart and bought some hooks with rare-earth magnets in them!  One is shown in the lower left of the first photo.  The diameter is 20mm - slightly smaller than the previous hooks.  However, with the NIB magnet in the base, they are much, much stronger!  They don't pull off any longer.  Not only that, but I also replaced the hook (which will unscrew from the base) with a flat-head stainless steel machine screw (only about 1" long, but had to be metric thread of M4).  It is now easy to place or remove the utensil and they don't fall off.  Cool!  Cost for the magnets are less than $2 each for this size.
K&J Magnetics

GeoShapes

These are geometric shapes with a magnet inserted into the bottom surface. They come in different sizes and materials as you can see here.  Cost is about $15 for the set of bigger ones, and $7 for the set of smaller ones.  Great for math teachers.  Site for these is at Fridgedoor.com.  They were also at the Architecture.org store in Chicago.
Arbor , ScientificsOnline , AS&S , EdIn

Magnetic Drawing Board

This surface is similar to the familiar Etch-a-sketch, but instead of twisting knobs you use a magnet on the end of a stylus to draw your picture.  To erase the picture, simply wipe the screen with the slider (seen on the left of the screen) and it is white again.  Great for simple games.  This was a special at $1.
Arbor , ScientificsOnline , AS&S , EdIn

Magnetic Push-Pins

For offices that have steel-backed walls that prevent you from using regular push-pins, this is the answer.  These have NIB magnets in them, making them very strong.  Much more functional for the fridge, too.  These were from K&J Magnetics.  The cost is about $8.25 for 25 of them.
Arbor , ScientificsOnline , AS&S , EdIn

AcroBots

These are fun little fellows you can stick to a fridge, a filing cabinet, your metal desk, your car, and to themselves!  Magnets are in their hands and feet.  These were from ThinkGeek.com.  The cost is about $13 for 3 of them.  Larger ones are also available.
Arbor , ScientificsOnline , AS&S , EdIn