[4Data]

Can you give an example of a pendulum swinging upwards? Is that an inverted pendulum? [1]

[1] https://www.youtube.com/watch?v=5oGYCxkgnHQ

[sklogic]

Yes, that's a good example. The recipe I used for such demos was based on an old Soviet electric shaver and a standard bicycle wheel spoke, it's a known combination to get an inverted pendulum (even at funny angles, not necessarily entirely upward).