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APPARATUS

The hurricane balls are two steel balls welded together.  Spin them on a smooth surface.  At sufficiently high rotation rates, one ball will rise off the table and the system will spin with its axis of symmetry at an angle to the tabletop for several minutes.  The motion is similar to that of a precessing top, but with a stationary center of mass.  In the steady state, the ball in contact with the table rolls without slipping, so frictional losses are minimal and the balls continue to spin for some time.

The critical rotation rate, below which a steady state will not be achieved, is 9 Hz for this set of 16-mm diameter balls (see AJP article linked below). Typical rotation rates when the balls are spun by hand are around 20-30 Hz.  An air stream from the nitrogen tank, or perhaps air blown through a straw, directed at one side can be used to increase that by a factor of two or three.

Slow motion video taken at 1200 fps

Am. J. Phys. 83, 959 (2015)

W L Andersen and Steven Werner 2015 Eur. J. Phys. 36 055013