Simple Geomag Constructions

GEOMAG is the brand name of a magnetic construction set that at it's simplest consists of short (strong) magnetic rods and chromed steel spheres. With just these two basic elements, an infinite number of geometric shapes and structures can be easily built and taken apart. My kids love making things with them, with the advantages that they're basically unbreakable, nor do they need batteries! The only downsides are the reluctance to take apart constructions, leading to requests for more components and a reduction in the available living room floor space for the adults as the creations are displayed!

The spheres are nickel-plated steel balls, while the rods are short, rubber-covered connecting sticks with a magnet on each end, giving each rod a 'North' and a 'South' end. The rods will join directly North to South, but repel when North-North or South-South ends are brought together.

You can also add panels to help construct rigid structures but they're certainly not essential and many things can be constructed without them.

One of the most simple, but still interesting, things to make are "Nodding triangles", which take just 6 spheres and 12 rods to make.

This can be done using other sizes of triangle, but a side of length 2 seems to work best, as a side of length 1 flips over too easily, while longer lengths don't bounce as well.

1. Arrange the 12 rods in 2 lines of 6, thus ensuring that the rods are all arranged N-S-N-S-N-S.
   
2. Place spheres every 2 rods, then join the beginning and end of each line to make triangles
3. Take one side of each triangle, remove the two rods (as a pair) and replace them the other way around.
4. Try and put the two triangles on top of each other - you should be able to find an arrangement that has two corners repelling each other, while the other two corners attract.
   
5. At this point, a gentle tap should have the top triangle nodding gently.

or "Spinning Pyramid" :-)

This just takes 6 rods and 7 spheres but demonstrates an interesting effect...

1. Take 2 spheres and connect 3 rods to each, to produce 2 tripods.
2. Place 3 more spheres on the bottom of the rods of one of the tripods, then join the other tripod's rods to the new spheres too.
3. At each end, put a rod and sphere together then connect the sphere to the sphere at the end of the shape.
4. You should be able then to hold the last two rods connected vertically at the top and bottom of the shape and by moving them together or apart, adjust the shape between them.
5. Start with them close together, start the shape spinning then watch what happens as you move them together, then apart, then back together again!