PSU Magazine Spring 2000

In time, the U.S. Slow-Pitch Softball Association, National Collegiate Athletics Association (NCAA), and American Softball Association (ASA) developed stan– dard that call for a speed of not greater than 125 feet per second for a ball after it makes contact with the bat. This is known as the bat perfor– mance factor or BPE The higher the number, the greater the performance. The BPF of a wood bat is 1; the allowed BPF for an aluminum softball bat is 1.2. A certaining a new bat's BPF from the ASA test facility can take six weeks. Each time DeMarini came up with an improved bat design, the company had to send it out forte ting Making sure the bat keeps the ball in the park. By Melissa Steineger to ensure that the tweak had not made the bat exceed standards. In the competitive arena of sporting goods, waiting ix weeks for results on a good idea did not make for good business. DeMarini figured that having its own te t equipment would allow the com– pany to determine results as needed. Official certification would still go through an East Coa t benediction. E nter Turcic, who has been a mechanical engineering faculty member at PSU since 1990. With a $34,000 grant-half from DeMarini and half from private matching funds of the Oregon Metals Initiative, an industry group--Turcic launched the project in June 1999. "The project seemed like it would be simple, and it would be if all we had to do was shoot a ball out of a cannon," says Turcic. "But it's quite an interesting challenge to do everything so precisely." Graduate student Danny Lee began researching the project. Not wanting to reinvent the wheel, Lee spent three months researching patent files and examining recreational oftball launchers. Nothing could meet the rigorous 15-page ASA tandards. Since the standards were new, data wa scanty. Companies that had developed the equipment, while willing to sell the entire test apparatus, were reluc– tant to share information. Turcic and Lee turned to the draw– ing board. After considering various mechanical methods, they resorted to using an air-pressure cannon, but the precision factor proved tricky. The first cannon produced too much spin and impreci e speed . With Lee meticu– lously machining custom one-of-a– kind equipment, the pair enlarged the cannon's diameter and used a carrier to hold the ball. This kept it from spinning and had the advantage of being adjustable in size. A carrier could be sized to hold a baseball, tennis ball, or even golf ball for future testing needs. But the carrier fractured under the stress. "We were always thinking things would be simpler than they were," says Lee. "It could take weeks to olve a little problem, and there was a new problem every week." Eventually, though, they cracked the question of generating accurate propulsion. The second tep of the proce s i to measure the ball's speed-a simple enough procedure accomplished with a pair of photo sensors. F inally, ball meets bat and the bat's speed of movement away from the impact of the ball is mea ured. That too, was a straightforward equa– tion: a tachometer measures the velocity of the bat movement and displays that velocity as voltage. The amount of voltage translate to a specific speed. With the challenge virtually met, a few problems were still being tweaked in March. Turcic expects to complete the test equipment this spring. "This equipment will be very bene– ficial for us," says Mike Eggiman, head mechanical engi– neer at DeMarini Sports. Buying simi– lar test equipment would have been more expensive, Eggiman says, and the company felt good about providing an educational project at PSU. Although the project took ome– what longer than Turcic hoped, he is happy with the result. "The hardest thing to convey is that we thought it would be easy, but it was hard," he says. "Still, in the end we were succe sful." 0 (Melissa Steineger, a Portland freelance writer, wrote the article "Give and Take," which appeared in the winter 2000 PSU Magazine.) (Illustration by Christopher Stine.) SPRING 2000 PSU MAGAZINE 13