Sakai top
The Sakai top (also known as paper clip top ) is a wire construction that the Japanese physics professor Takao Sakai devised as an exercise for his students in 1986. The task here is to construct a functional top from a short piece of metal wire of a defined length, for example a paper clip .
With a little skill, the top can easily be bent out of a paper clip.
construction
To realize the gyroscope it is necessary that part of the wire is used as a flywheel , another part as the axis of rotation and another part to connect the two aforementioned parts. In order to obtain the greatest possible moment of inertia , the centrifugal mass, curved in a circular arc shape, should have the greatest possible distance from the two-part axis of rotation. Two connecting spokes are necessary to connect the arc to the axis of rotation.
The axis should go through the center of gravity of the construction. If the gyro ring were closed to form a complete circle, the mass of the two connecting spokes would shift the center of gravity of the gyro from the axis of rotation outwards. Therefore, the circular ring must be designed in the form of an arc. The opening angle of the circular arc-shaped gyro ring must be chosen to be just large enough that the center of gravity of the gyro lies exactly on the axis of rotation. This condition is given at an opening angle of 53.13 ° (= 0.9273 radians).
Web links
- Uni-Muenster: The spinning paper clip (PDF file; 348 kB)