Why is it necessary to hold the ball firmly while it is spinning?

Your shiny new Powerball is a superlative, hand built product which has been precision balanced using an advanced computerized jig to ensure zero vibration at speeds in excess of 16,000rpm.

However, despite this perfect form, the nature of the design requires that there be a small amount of �play� (up/down movement) between the rotor and the outer sphere case. (If you really must know why this play is necessary�or if you simply like all that technical stuff, then please click here for more details on how your Powerball builds its speed!).

As the rotor spins, it generates a force called �inertia� (this is what occurs when you try to alter the direction of a fast spinning metal disc/object�the faster you spin, the harder it fights against your efforts!)

Now, the rotor in your Powerball is indeed perfectly balanced and won�t vibrate in any way - however, because of that little bit of up/down �play� we described earlier, if you fail to grip the ball really firmly during operation (and, say, let it sit loosely in your hand as the rotor spins), what happens is that the inertia being developed will cause the whole sphere to resonate in sympathy, causing degradation of the internal support band on which the rotor itself is suspended. Each time this happens, the polycarbonate rotor support band will shed a fine coat of tiny particles from its surface (plastic dust as it were!), which will end up inside the rotor support band cavity, making your formerly smooth, quite Powerball rough and noisy!

Over time, this dust accumulates and ends up being pulverized into the sphere�s surface by the metal axle with each rotor revolution causing disharmony between the sphere and the support band and ultimately causing significant speed deterioration in the Powerball.

Moral of the story; keep the Powerball gripped firmly at all times during use!