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'Powerball' is a trademarked name for gyroscopic exercise devices produced by Nanosecond (NSD). Later patents for the Powerball device cover its extra features such as rev counters and gyro-powered LED lights. The light-emitting diodes are powered by a small generator embedded in the gyroscope.
The toy itself is a small ball made of plastic or metal, and is commonly marketed as a gyroscopic wrist exerciser. It can be started with a short rip string or by a snap of the thumb. Once the gyroscope inside is going fast enough, a person holding it in his hand can accelerate the gyroscope to incredibly high revs by following a circular wrist motion with the device. Modern devices come with electronic rev counters (current record is 16,317rpm, set by Akis Kritsinelis from Greece Video here or here). Kritsinelis has also set a 90 second strength record of 20,082 revolutions see video.
Other Powerball models on the market today are the "Powerball 350Hz Metal" and "NSD SuperPowerBall". These powerballs are made primarily of metal and have twice the weight of "regular" Powerball models. They are also more difficult to operate since 250Nm of torque is produced when the internal rotor is rotating at high revs.
In December 2006, a new Powerball model was introduced called the "Powerball Signature". This powerball is made of mirror-gray plastic and features "sapphire" white LEDs and a much more stable rotor. The link shows an operational Powerball Signature model [1].
In the summer of 2007 a new model of Powerball was created called the "Powerball Screamer". The Screamer is based off the Powerball 250Hz model, however, it has 8 holes drilled in the rotor itself. These holes generate a very loud sound even when the rotor is rotating at low speeds. For example, the sound of this powerball rotating at 10,000 RPM is almost equal to the sound of a regular Powerball rotating at 15,000 RPM.
Nanosecond's Powerball was the first to feature electronic rev counters and a generator for light-emitting diodes, both of which made it attractive for professional and educational use.
At first glance, the physics of this device appear confusing. However, they are surprisingly simple and can easily be understood with a little knowledge of gyroscopes. Their striking property is that the axis of a spinning gyroscope will resist a force applied to it and will start rotating perpendicular to the force applied.
The axis of the gyroscope in the gyro Powerball is fixed to the spinning mass and it rests in a little groove inside the wrist exerciser device, which almost completely covers the gyroscope inside it except for a small round opening on top where you can manually start the gyroscope. Once the gyro is spinning, tipping the device will cause the gyroscope to start precessing, with its axis slipping around in the groove in a circular fashion. The groove inside the device is a little wider than the axis, and the gyroscope's evasive action towards the externally applied force will cause one end of the axis to push against the upper rim of the groove, while the other end of the axis pushes against the lower rim of the groove. While the axis is slipping around inside the groove, the friction between the axis and the groove rims will accelerate or brake the spinning gyroscope, with a maximum effect when the axis starts "rolling" inside the groove. Since this friction force is essential for the device's operation, the groove must not be lubricated. The acceleration of the gyroscope is best when the precession of the gyroscope is supported and amplified by wrist motion.
It takes a while before one finds the "rolling" point, but the gyro will also be accelerated to a smaller extent by the slipping friction.
The device is covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by P.S.Chuang and 6,942,601 (2001) by P.S. Chuang

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External links

External links

★ Powerball International website, Shop

★ Gyrotek Powerball Fan Site

★ Nanosecond website