Buckyball Construction

Author
What are Buckyballs?
Disclaimer
How Many Do You Need?
On the Floor
Eyes Closed
Magnetic Orientation
Triangles and Stability

Starball

Author

This website is written and maintained by Karl Dahlke. All material, including buckyball designs, is copyright © Karl Dahlke, 2017. Please visit my home page to learn more about me.

What are Buckyballs?

Buckyballs are pea-sized rare-earth magnets that snap together to make interesting shapes. See the starball example shown above. The design and construction of these shapes is a wonderful confluence of geometry, magnetics, engineering, and art. Patience is also required; it can take several hours to build an elaborate shape. You can get 90% of the way there, and then a small slip causes the entire structure to implode. Even a slight misalignment is almost impossible to repair after the fact. You might try to push a ball back into place, but then another ball snaps out of position. Soon the entire shape is compromised. Take a deep breath and start again - and remember, it's just for fun.

This website provides tips and tricks for building these elaborate structures. Some day I may create youtube videos, but for now, still pictures and written instructions will have to do. I hope these explanations are helpful. Please send along your feedback.

Disclaimer

Buckyballs were originally marketed as a child's toy, but they were taken off the market in 2012. Why? Because some children tend to eat their toys. If you eat one ball, or a conglomerate of balls, that's fine, you just poop it out. But if you eat one ball and wait a couple hours and eat another one, they will be in different places in the intestine, and if they happen to approach each other on opposite sides of a wall they snap together and do not move. These are strong magnets! Surgery is required to remove them.

After a 5 year hiatus, they can legally be sold in the United states once again, as of January 2017 - so buy them while you can. Buckyballs are now marketed to adults for "stress relief", with plenty of warnings on the box. To protect myself from liability, I will repeat those warnings here. Don't eat the buckyballs, and don't put them on or around your body. Placing 2 balls on opposite sides of thin tissue, such as a lip or ear lobe, can cause injury. Keep buckyballs away from children and pets. Don't place them near electronic equipment, especially screens or magnetic storage devices.

How Many Do You Need?

Buckyballs are sold in sets of 216, packaged in a 6 by 6 by 6 cube. This isn't really enough to make very many shapes, so you'll want more than one set. On the other hand, buckyballs aren't cheap, so I don't expect you to run out and order 10 sets. Nor do I want this to become a contest of quantity (like lego competitions). Obviously you can build larger and more elaborate structures with more balls. This website aims for a middle ground - 3 to 4 sets. Everything presented here can be built with 800 buckyballs or less. You don't need more than that to have a lot of fun.

On the Floor

Throughout this website, I often refer to a table, as though you are building your shapes on a table. However, I like to build my shapes on the floor. The carpeting helps hold the shapes in place during assembly. A smooth table has insufficient friction, and your structure can slide about while you are working on it. Remember, a tiny slip can ruin everything. If your back does not allow you to work on the floor, you might want to put a placemat or tablecloth on the table to provide a bit of static friction.

Eyes Closed

After several months of practice, you might be able to build these shapes with your eyes closed. That's what I do, because I am totally blind. My daughter Beth takes pictures with her smart phone and sends them to me for inclusion in these web pages. If you would like to crop them, or otherwise improve their quality, please let me know.

Magnetic Orientation

Once you take your buckyballs out of the packaging, they clump together into one large glob. Grab a few balls between thumb and index finger and pull gently, extracting a tail. If the tail breaks off, move it to a new location on the glob and pull again. It's easy to make a long tail consisting of 40 or 50 buckyballs. How are the magnets aligned in this tail?

As you know, every magnet has a north and a south pole, and opposite poles attract. A buckyball doesn't look like a bar magnet, but like the earth, it still has a north and a south pole. There are two possible arrangements for the magnets in the tail.

  1. Lay the tail out in a straight line on the table, traveling right to left. One ball could have its north pole facing up, just like the northern hemisphere of the earth. The next ball could have its north pole facing down, like the earth upside down. The tops attract each other, the first being north and the second being south. At the same time, the bottoms attract each other, the first being south and the second being north. The third ball in the tail has its north pole pointing up, just like the first. Poles alternate up and down as you move along the tail. That works, but it feels rather unstable. If you jiggle the balls even slightly, it seems like they would flip into the second configuration described below.

  2. As the tail extends to the left, each ball has its north pole pointing left. The north pole of each ball attracts the south pole of the next ball in line, and it all works out.

Science is not the same as intuition, so how can we prove that configuration 2 is correct? Stretch out a tail of 30 balls or so, then break off the end, about 11 balls worth. Flip it around and try to reattach it to the tail. Notice how it jumps away? You are pointing two north poles at each other, and they repel. Our intuition is correct; buckyballs line up north to south, north to south.

As you build your shape, orientation is key. Always keep a tail going, always pointing to the left, so you never lose track of north and south. Break off a section of tail about 12 balls in length, then pull the ends towards you to form a circle lying flat on the table. This is a ring, 12 balls around, and the north poles run counterclockwise. Now do the same thing again. You have two rings, each with north running counterclockwise. Gently slide them together until they connect. Notice that the balls line up side by side. At the border, north points down on the right, and up on the left. Corresponding hemispheres attract, and corresponding balls attract. You can put dozens of rings together this way and the resulting shape will be stable.

Now suppose you made a mistake. Create the first ring as before, but build the second ring by pushing the ends up and away from you instead of towards you. North runs counterclockwise in the first ring, and clockwise in the second. Slide the two rings together and watch what happens. Balls alternate at the border. They don't line up side by side any more; it looks more like a zipper. This is because north points away from you on both sides. The north pole of one ball has to touch the south pole of the neighboring ball, so they interleave. This is fine if you only have two rings, but it doesn't support large scale structures. Each ring must be made the same way. Always pull the ends towards you, so that north always runs counterclockwise. Rings will join together consistently to make walls, and then 3 dimensional structures.

Aligned rings, Misaligned rings

If you ever lose your tail, then you have lost your orientation. Pull out a new tail and make a new ring, then gently attach this ring to your growing structure and see if the balls line up. If they do, then you have reestablished your orientation. If they don't, then you have to turn the tail around, but there is a bigger problem. Your ring is pasted onto the side of your structure with balls interleaved. You must gently pry it away without pulling the structure apart. Long nails help in this endeavor, so you girls have an advantage. In any case, it's not easy! This could be a start-over moment. So always retain your tail. And don't leave a short tail of just a few balls. It can easily snap back onto the glob while you are working on your structure. You hear that disturbing snap, and when you look down, the tail is gone. Always leave a tail of at least 15 balls pointing to the left.

Triangles and Stability

A protein is a linear molecule, but it folds into alpha helices and beta sheets, and then it attains its 3 dimensional structure. In the same way, a line of buckyballs creates triangles, squares, etc, and these snap together to make various shapes. Within a few hours of trial and error, you will see that triangles provide stability. You can have other shapes here and there, but you need a preponderance of triangles. This dome contains triangles and pentagons, but mostly triangles.

cylinder wall with hemisphere top

Take a string of 9 balls off the tail and bend it into a circle. Take 3 balls between thumb and index finger and pinch them into a corner. Move around and pinch the next corner, and then the third. Often the first corner will pop back out into a circle while you are closing the second. It happens. Keep going around until all three corners hold. It comes with practice; it really does. Soon you have a triangle with 4 balls on a side. Each corner ball participates in two sides of the triangle, thus a triangle comprising 9 balls has 4 balls on a side. A 12 ball triangle has 5 balls on a side, and so on. Make rings of various sizes, (always a multiple of 3), and then turn them into triangles. Once you can do this quickly and easily, turn the page, and we'll make our first shapes. Warning - if you don't have a friend helping you, you may at times need to build or repair these triangles with one hand, while you hold your structure up with the other. One time I held my project in the air with one foot, whilst I repaired several triangles that had popped open.