Reinventing a magnetic toy – the Levitron

Levitation is one of these things that everyone thinks is cool. As a kid, I already tried out many times finding the right arrangement of magnets so they would float on top of each other. Finding out that some mathematician already proved this to be impossible hundreds of years ago was quite disappointing (Earnshaw’s theorem). Luckily there are still options that require some level of active component. For example Spin-stabilized magnetic levitation.

This kind of levitation is extremely sensible. It takes hours to find the right weights to put on the spinning top. And even then it eventually drops again. I wanted to find a way to give the top energy continuously and possibly make the setup process easier. I already found a video by nikos 44317 proving that it can be done. He used electromagnets that were oscillating at exactly the same frequency that the top was spinning at. My idea was to not use electromagnets but to spin the whole base magnet plus an additional magnet that would be responsible for the magnetic field in the radial direction. This way not only could you generate a stronger radial magnetic field where the top is, but also any production imperfections of the base magnet could be canceled out – that’s the theory at least.

So I started trying around by constructing a base that does what I want. In the first two iterations, I still had the goal to place the base on a sort of gimbal so that it is always perfectly level. However, this caused more issues than it solved. The assembly was a lot more complex and as I later found out myself when you spin something 3d printed at up to 5000 rpm every little imbalance gets amplified so that the whole thing wobbles like crazy.

In the last design, the spinning base was bolted to the table, but still, the vibrations made it basically impossible to get the top levitating while my poor flimsy table was shaking like crazy. This might be a project that I will revisit sometime when I have better resources available. So far it has been quite disappointing. Seems to be a common theme when it comes to my levitation projects 🙈

I already have some future ideas that involve a simulation of the magnetic base with the help of analytical expressions. Here are some teasing pictures: