Levitron facts for kids
The Levitron is a cool brand of toys and gifts that float! They are sold in science and education stores by companies like Creative Gifts Inc. and Fascination Toys & Gifts. The most famous Levitron toy is a spinning top that uses a special trick called spin-stabilized magnetic levitation. This means it floats using magnets that are moving, which is different from other floating toys that use electricity. From 1994 to 1999, over 750,000 of these tops were sold!
Contents
How the Levitron Top Works
The Levitron top is a permanent magnetic ring. It floats above a magnetic base plate. For the top to float, everything has to be just right. This includes how fast the top spins and how much it weighs. The Levitron top uses the power of magnetic fields and gyroscopic stabilization to float. This means its spin helps it stay steady in the air. The top's spin slowly gets slower because of air. So, it can only float for about four minutes unless something helps it keep spinning.
Making the Top Float
To make the top float, you first put a plastic plate on the magnetic base. Then, you spin the top very fast on this plate. It needs to spin between 25 and 50 times per second (1500 to 3000 rotations per minute). If you spin it too slowly, it will fall over. If you spin it too fast, it won't settle into the right spot and will slide off. It can be hard to spin it fast enough by hand. So, Creative Gifts made a special battery-powered tool to spin the top with an electric motor.
Next, you carefully lift the plastic plate. If everything is perfect, the top will rise and float above the plate. The top also needs to be weighted correctly. The kit comes with different washers to add weight. If the top is too heavy, it won't lift. If it's too light, it will fly away.
Why the Top Falls
After a few minutes, the top usually falls. This happens because air friction slows its spin down. Once it spins too slowly, it can't stay floating. Other things can also make the top fall. These include the air temperature, small air currents, or even tiny shakes in the ground.
More advanced versions of the Levitron can keep the top floating forever. They do this by keeping the top spinning constantly. The makers of the Levitron also created a "Perpetuator." This device sits under the Levitron. It sends out extra magnetic pulses. These pulses gently push the spinning top. This helps it keep a constant speed. With a steady speed and a perfectly level base, the Levitron top can spin for a very long time.
The Levitron Story
Who Invented It?
The idea for a floating magnet that spins to stay stable came from Roy Harrigan in Vermont. He invented it around 1976 and got a patent for it in 1983. In the mid-1990s, a businessman named Bill Hones from Seattle found Harrigan's patent. Hones was also trying to make magnets float. He contacted Harrigan and borrowed his floating device. Hones, with help from his father (who was a physicist), studied the device. Then, Hones applied for his own "improvement patent."
Around the same time, in 1984, another inventor named Joseph Chieffo from Pennsylvania also discovered how to make magnets float using spin. He made his own spin-stabilized magnetic levitation device. When he tried to get a patent, he found out about Harrigan's patent. So, he stopped trying to get his own patent. However, his lawyer told him he could still sell his device without breaking Harrigan's patent. In 1988, Chieffo started selling his device as a kit. His device had a flat base magnet, which was similar to the base magnet in the popular Levitron toy that Hones later patented. In 2012 and 2014, people even made Levitrons float at an angle, like 45 degrees, or even flat on their side! This was done with extra magnets. The flat-spinning Levitron is very stable and good for learning.
A Business Disagreement
In the 1990s, a company called "UFO" was formed by Michael and Karen Sherlock. They had a spoken agreement with Bill Hones' company, Creative Gifts, Inc., to sell the Levitron. But their agreement didn't become a written contract. Things got difficult when UFO learned about Roy Harrigan's earlier invention. UFO then changed their website to say that Hones had "stolen" the invention from Harrigan.
Because of this, Creative Gifts sued UFO. They said UFO was using their trademark unfairly. In court, Creative Gifts won their case. UFO had tried to defend themselves without a lawyer. The court found that UFO had not followed the rules for sharing information. The appeals court also agreed with the decision. They noted that UFO's legal papers were very short and didn't explain things well.
See also
- Electromagnetic suspension
- Electrodynamic wheel
- Magnetic bearing
- Electrodynamic bearing
- Spin-stabilized magnetic levitation
