Some years ago, David, an elementary School teacher wrote me asking if I can help them designing a 2×2 Rubik’s cube for children.
They want a mathematical project for kids based on Rubik cube. Fastly I answered with some links to learn to build 2×2 and 3×3 Rubik’s cube with dices and magnets. The are really cool hacks. But David needs something easier and cheaper. They came with simple premises.
- Children of 10 years must be able to build it, so we forget about elaborate and dangerous tools and processes
- and it has to be cheap, very cheap
although everything must be said they just wanted a minimally manipulable cube.
My solution is this Rubik 2×2 cardboard and magnetic paper cube. If you do for a class it will cost approximately $1.5 per cube, if you just want to make one you get up to $3 or $4
Finding the solution didn’t cost me much because I didn’t have many options. It was clear that a magnetic solution had to be made and the cubes to be cheaper and easily manipulated would be made of cardboard.
We need 8 cubes. We have designed them 3cm sideways so that the final cube has a size of 6cm x 6cm similar to a normal cube and easily manipulated by children.
I have used 2 glued cards, in this way the rigidity of the cube is increased and it will endure the abuse that they will suffer for a class of 10 year olds :S
We cut and we have everything ready.
Important points. If you want to paint the sides with colors, now is a good time to manipulate each cube. And if we want to give it even more protection in addition to the double cardboard we can plasticize it. But don’t plasticize your eyelashes or you won’t be able to fold them
For an adult it is very easy to manipulate the cardboard and fold it to glue the cubes, but for a 10-year-old child it may not be so trivial. So it may be a good idea to explain that to assemble the cube we can first bend over a corner and then we will already mark strongly with the nail.
Eight cubes and we have them all ready to make the magnetic joints that will unite and allow the modules to move together.
This starts to take shape 😉
Now I will make the magnetic joints that will hold the cubes together.
How to make magnetic joints
The Rubik cube, needed magnetic unions. And I doubted between using magnetic paper or neodymium magnets. The 2 solutions are very cheap.
The problem with neodymium magnets is that they can be too powerful and in addition to their effect is punctual, while we distribute the attraction with the magnetic paper all over the side of the cube.
This paper is 2-sided photo paper, on the one hand it has a magnetic part and on the other photo paper we can put in a printer to get our stickers for refrigerators.
We need 3 joints per cube, so we will cut 24 squares.
If the cardboard cube has 3 cm of side, cut the magnetic paper into squares of 2.8 cm if they make it 3 cm it will protrude from the cubes and if we do it very small it will have less adhesion, the squares must be made as much great possible because the force exerted by this role is not very large, although enough to keep the cubes glued together.
When gluing the magnetic paper into the cubes, you have to be very careful. The leaves have a kind of grooves, they are covered with tiny parallel lines. If 2 of the squares we have cut, so that the lines have the same direction, they attract, if we put them in such a way that they are perpendicular, they are not attracted.
Knowing this and taking into account, the rotation of one in the cube, we will have to alternate the directions of the paper while we glue, so that as it turns it always has adhesion
And once with the 8 cubes ready, in addition to the Rubik we can play a little with other assemblies.
With this there is everything. I have painted it quickly, but it can be customized as we wish.
How to manipulate and use the rubik cube
The cube fulfills the desired functions.
- It can be built by children, you just have to paint, cut and paste
- it’s very cheap, $1.5 for bubo rubik
- moderately manipulable
And at the last point is where I would like to influence. It cannot be manipulated with rotation like a normal cube. The idea is to take each part of the cube with one hand, separate a few millimeters and turn it
We imitate the rotation of a normal Rubik but separating it a little. But the effect is very good, because when we release the cubes they remain stuck.
Although I have to say that sometimes if we don’t do it carefully, it loses its grip and is dismantled.
But, I hope this solution is good enough for David and his school.