River Grove, Ill. — It's the dimples that get them to the dance, and golf ball manufacturers dance to the tune of the US Golf Association. ``The USGA limits the size, weight, and initial velocity of a golf ball, so the only thing left to experiment with is aerodynamics, and that means getting the right number of dimples and getting the right size, shape, and depth of the dimples,'' said Paul W. Jones Jr., vice-president for research and development at the Wilson Sporting Goods Company, as he examined a golf ball in his suburban Chicago office.
Dimples -- those little circular depressions that characterize the surface of a golf ball. They play a major role in determining just how far the ball will go, how much it rotates, and which direction it will take on impact.
Until a year ago, engineers at companies like Wilson, Spalding, and Acushnet would play with dimple patterns by using a bowling ball as a model and pasting paper circles all over it. Toolmakers would then construct a prototype golf ball from the bowling-ball design and engineers would test its carry, roll, and trajectory.
Enter the computer: The bowling ball and much of the testing have been bypassed by computer graphics.
``We used a software program written by Steve Aoyama, an aerodynamics engineer, that allowed us to sort through many iterations of golf ball dimples,'' Mr. Jones said. ``We tested about 800 configurations and the computer showed us the optimum patterns we should try: 78 variations we could build and test. We ended up with our 432 series -- 432 dimples. And instead of the golf ball's symmetry being along a single line between its hemispheres, we were able to develop multiple lines of symmetry; 16 ways you could rotate it and have it perfectly symmetrical.''
Wilson, recently acquired from PepsiCo by Wesray Capital Corporation (whose chairman is former Treasury Secretary William Simon), had developed an image that could be called stodgy even in the conservative sporting goods industry. Then, in 1983, John Cranor became president and hired Mr. Jones away from General Electric.
``John decided we were going to be an innovator, a leader, a reputation Wilson had once enjoyed but in the past few years had not,'' Jones said.
``He wanted us to apply the technologies that exist today but hadn't been applied at all in sporting goods and products. It meant taking a very traditional industry and marrying it to a technology that's been around since 1977 or '78, CAD/CAM [computer-aided design/computer-aided manufacturing].''
In June of 1984, a $2 million Applicon Bravo computer system was installed. Soon it was accepting designs for scores of Wilson sports products: not only golf balls but golf clubs, basketballs, tennis balls, and tennis rackets.
``By September, I was able to dictate that all new rackets come out of the system,'' Jones said. ``They were truly engineering-designed, not the old cut-and-try method.
``Normally it takes eight to 12 weeks for nothing more than the cosmetic approval of a tennis racket, and then you go through a whole series of cut-and-tries,'' he explained. ``Now we have the confidence factor that the products are going to play very well -- that they're going to have performance. Now we're kicking complete racket designs out in a week and the cosmetic decisions are made in a matter of days or hours.''
The use of computers to design products has helped Wilson establish a market niche in the ``game improvement'' market -- sporting goods designed for the amateur. Weekend athletes have a tendancy to ``see some pro on television and say, `Boy, I really want to play like that,' and then they'll get a racket endorsed by the pro, and they'll try to play with it, and they'll get very frustrated. What they want is something that will help them enjoy the game, even if they go out and play only once a month or once every two months,'' Jones said.
Hence tennis balls are 7 percent larger and 15 percent slower than what the professionals bat about, but with the same weight and feel. Game improvement, a major growth area for the entire sporting goods industry, has also prompted such design innovations as oversize tennis rackets, hollow golf irons, and basketballs designed for weekend-schoolyard play.
Engineers at Wilson Sporting Goods say computer design is helping them penetrate that marketplace. Mr. Jones has discovered an added benefit that strengthens the company.
``It's really helped our recruiting. We can go to aerodynamic engineers on college campuses who might normally be going into aerospace and say, `Hey, look, we've got something exciting over here.' ''