WHEN YOUNG Alan Adler wasn’t modifying broken toys or building model rockets from scratch, he earned extra spending money around the neighborhood repairing electric plugs and faucet washers – for a dime. Now the Palo Alto resident is hustling a tad more pocket change with his brainchild, the far-flying Aerobie ring.

Skirting college, Adler entered electronics as a technician. He taught himself aerodynamics to quench a thirst for sailing and designing better sailboats. His risky but successful virgin project, a radically light 40-foot craft, characterizes his willingness to brave uncharted design waters.

“With electronics engineering, it’s very easy to make changes on the table, often in a matter of minutes or hours,” says the 56-year-old Adler, who holds more than two dozen patents. “But this boat took a year to build – and if it had been incorrectly designed, it could have been a piece of scrap.”

In the late 1970s, after spying the aerodynamic drag the inch-thick Frisbee encountered, he tried to come up with a thinner flying disc that soared farther. When he punched out the center to create a ring, he scored.

“I went out to a lawn on [Palo Alto’s] California Avenue in front of an industrial building and I threw this ring. It floated along almost magically! It looked like it was levitating. I can still picture that ring in my mind.”

Adler worked feverishly for a few weeks and briefly licensed his brainstorm to Parker Brothers as the “Skyro.” But the company didn’t maintain the thousandth-of-an-inch precision he demanded for straight flights.

Still unsatisfied with his creation’s flight accuracy, Adler toyed and tinkered until his fifth prototype – with a rim around the edge – passed the test. With typical boldness, he and his wife funneled thousands into starting their own company, Superflight, before Adler was even sure the required exactitude was achievable in mass production.

But when Aerobie sailed into toy stores in 1985, 24-year-old Scott Zimmerman threw it 1,125 feet into the Guinness Book of World Records, and ring sales skyrocketed. It’s now joined by a returning Orbiter and an upcoming perfect-spiral football with twisted fins.

“The real kick for me is if I’m in a park or in the schoolyard or the beach and I see some people playing with something I designed,” beams the Stanford engineering lecturer, who can hurl his Aerobie about 470 feet. “I get a real charge out of that, much more than the esoteric idea there are thousands of people out there playing with them.”