The Original TEDCO gyroscope toy (with a clear display box)

The original TEDCO gyroscope toy has perplexed young and old for more than 100 years

The TEDCO gyroscope toy was first produced in 1911 (not 1917 as is often claimed) by Hurst manufacturing. It was later produced by Chandler manufacturing under the name of 'the Chandler Gyroscope'. In the first half of the 20th century, this gyroscope toy was widely found in the variety ("five and dime") stores across America. In 1982 the Chandler Gyroscope was purchased by TEDCO. The look and construction of the TEDCO gyroscope toy has remained unchanged for more than 100 years. It continues to perplex young and old alike with its peculiar ways that seem to defy gravity.

With each Tedco 'Original' gyroscope you get:

The Gyroscope
Pedestal/tower
Pull string
Clear plastic cube to store and display your gyroscope
Complete set of instructions

Note: There is a small break in one of the outer rings. It is a "butt" joint, where the two ends butted together. It serves two purposes, it aids assembly and also allows for a minor degree of adjustment. Don't worry, the design is basically about 100 years old now.

The principle behind the TEDCO Gyroscope Toy

This mysterious effect is precession. In the general case, precession works like this: If you have a spinning gyroscope and you try to rotate its spin axis, the gyroscope will instead try to rotate about an axis at right angles to your force axis. When the force is applied to the axle, the section at the top of the gyroscope will try to move to the left, and the section at the bottom of the gyroscope will try to move to the right.

Newton's first law of motion states that a body in motion continues to move at a constant speed along a straight line unless acted upon by an unbalanced force. So the top point on the gyroscope is acted on by the force applied to the axle and begins to move toward the left. It continues trying to move leftward because of Newton's first law of motion, but the gyro's spinning rotates it. As the two points rotate, they continue their motion.

This effect is the cause of precession. The different sections of the gyroscope receive forces at one point but then rotate to new positions. When the section at the top of the gyro rotates 90 degrees to the side, it continues in its desire to move to the left. The same holds true for the section at the bottom -- it rotates 90 degrees to the side and it continues in its desire to move to the right. These forces rotate the wheel in the precession direction. As the identified points continue to rotate 90 more degrees, their original motions are cancelled. So the gyroscope's axle hangs in the air and precesses.