By Yu-Wen Zhang
In 1883, a French mathematician, Professor Édouard Lucas, introduced in a magazine an attractive puzzle named “Tower of Hanoi”.
It is a puzzle game that combines practice and logical analysis. In gaming, it classifies as a one-person puzzle, similar to Peg Solitaire that are often be seen in Chinese culture.
Legend has it that the puzzle comes from a temple in India. The temple is located in the center of the universe, where there was a piece of wooden board with three long wooden rods. One the rod were 64 disks stacked in order of decreasing size, with the smallest at the top. The priests at the temple were instructed by God that only one disk may be moved at a time, and no disk may be placed on top of another that is smaller than it. According to the legend, when the priests move the entire stack of 64 disks to the last rod, obeying the above-mentioned rules, the world will end.
The following are steps with simple drawings to make such a toy.
Our design is the easiest one with only 3 disks in the stack.
As can be seen in the illustration, the game consists of a base, rods, usually three, and disks of various diameters.
The first version aimed at sketching out the outline of all pieces and making sure they can be assembled.
For the second edition, we took into account the specs for thickness and measurement of different pieces. Also, to make the design easy to hold in hands and to play with, we changed the design for the base from two layers of stacking to three, and the same for the disks.
In the third edition, our goals were to make it easy to assemble the pieces and reduce the differences of specs so that every piece could fit into its dent perfectly. The disks are usually pieced together with white glue, but we fear that there is not always white glue at hands, so we opted for tenons for fixture.
The fourth edition is the one ready to go into mass production. This is also where we did typesetting and fine-tuning. For instance, there may be space on certain parts that can help save the materials. Also, we could put in breakpoints, so that the parts will not fall apart. We were also thinking whether there should be more space at the tenon structure so that assembly would be easier.
Design proof & assembly
The key to design proof is to settle the material to be used and power for laser-cutting. During assembly, we also paid attention to whether there is interference between the parts or whether the burn marks from laser-cutting are too big.
When solving the puzzle, players should obey the following 2 rules:
1. Only one disk may be moved at a time.
2. No disk may be placed on top of another that is smaller than it.
Tuning up the level
There are also are some variations to try:
1. Increasing the number of disks
2. Increasing the number of rods, and the disk must be placed on a different pole each time it is moved.
3. Coloring each disk with two different colors into two layers, and no disks with matching colors should be stacked together.
Even children’s toy is full of the wisdom of predecessors, and playing is human nature. Through designing our own toys, learning the logic and wisdom in them, and finally creating new games, we can make the most of the Maker spirit and learn all kinds of things while having fun.