Magnetic Magic

Are there only two kinds of interactions between two magnets, either attract or repel? This time we are going to make a toy that causes two magnets to attract and repel each other at the same time, with 3D printing. Let’s find out more on the love–hate relationship between two atoms that Mr. Feynman wrote about.


Scientific theory:

The elastic lines of magnetic field have the following characteristics:

  • Parallel lines repel and move away from each other. 
  • Lines of the same direction will move towards each other and become shorter. 

The two large neodymium magnets from outside attract each other, which means they have different polarities facing up, while the small neodymium magnets on the edge will repel when the neodymium magnets on the right get close, then it will somehow reach a balance between attraction and repulsion.

If the main body (the yellow part in the above picture) moves left, the magnetism will drag the magnet on the right with it to the left, but will once again reach balance, going back to the original distance, and vice versa.

Bill of materials:

  • Models
  • Neodymium magnets D20*3、D6*4


Place neodymium magnets inside the array, pay attention to the polarities, click the video, and watch these amazing magnets dance the waltz.