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The New York Times Lift, Drag, Spin and Torque: Sending Toys Aloft
Principles
of aerodynamics refine the Frisbee and its ilk. Each summer, they fill the skies with aerobatic wonder. Above beaches, parks, picnic areas and just about any open space, they are like flocks of oddly shaped birds feathered in plastic, metal, cloth or wood. Whether soaring or diving, dashing or fluttering, zipping away or coming back, millions of throwing toys in diverse shapes, sizes and colors go aloft each day as testimony to human fascination with flight and competition. The insatiable appetite for things that fly continuously prods engineers and designers to develop new disks, rings, boomerangs and winged things that push the limits of performance and curiosity. Designers look for new ways to manipulate the physical properties that dictate flight characteristics. By experimenting with often subtle design changes, they attempt to control lift, drag, spin, angular momentum, torque and other forces that influence how and why an object flies. Some of the newer devices push the limits of toy aeronautics and puzzle even the experts on how or why they fly. Increasingly, flight toys depend upon precision design and manufacturing tolerances within a few thousandths of an inch to seemingly defy physics and fly better than their predecessors. A new device called the X-zylo, however, appears to have significantly upped the ante for this type of toy. The X-zylo, a hollow plastic cylinder weighing less than an ounce and measuring 3 3/4 inches in diameter and 2 1/8 inches long, has been thrown 655 feet, more than twice the length of a football field and besting the Frisbee distance record of 637 feet. The device, made by the William Mark Corporation of Claremont, California, was invented four years ago by Mark Forti when he was a business administration student at Baylor University and took some time off with friends to experiment with paper airfoils. Mr. Forti, who is marketing the device with the help of his father William Forti, a former aerospace industry executive, said experts still are not entirely sure how the cylinder works, including National Aeronautics and Space Administration engineers who examined it. But the device, which has a weighty metallic-plastic ring at its front end that makes its leading edge thicker, appears to fly through a confluence of aerodynamic and gyroscopic forces, Mr. Forti said. The high angular momentum of the spinning keeps the tube stable in the air and contributes to its lift, he said. "It's a simple device but that simplicity is deceiving," Mr. Forti said. "The cylinder has to be just right, in every dimension and characteristic, or it won't fly." |