Easton engineers are redefining the 'sweet spot'

With spring training now here, many people are looking ahead to one of those truly magical moments in sports. The pitch is delivered. The batter swings, making contact with the ball in just the right spot, at just the right time. The ball takes off-high, but not too high, and traveling fast. It lands on the other side of the fence. The crowd goes wild.

Generally speaking, when a hit is that perfect, the ball has come off the bat's "sweet spot," the point of connection that produces the fewest vibrations and thus creates the "sweetest" hitting sensation for the batter, with little or no sting generated in the hands and arms. With wood bats – used in Major League Baseball and its minor league affiliates – there's no controlling the size or placement of the sweet spot. It's just a question of where various nodes might have formed in the wood. But, with aluminum bats – the standard for play in the National Collegiate Athletic Association (NCAA), Little League and other amateur competitions – the sweet spot can potentially be wherever a hitter wants it … if he or she has the help of an engineer like Larry Carlson.

Carlson, who holds a B.S. in mechanical engineering and is vice president of research and development for Easton Sports Inc., spends a lot of time thinking about sweet spots and other ways that technology can improve athletic performance. A 14-year veteran with Easton, Carlson, who had previously worked for Alcoa, heads up a team of engineers working in the company's onsite Sports Lab in Van Nuys, Calif., which has launched a number of innovative new products, including baseball and softball bats, hockey sticks, tennis racket frames, drum sticks, bike frame tubing and accessories, and other sporting goods equipment.

As Carlson explained in an article for ChAPTER One Online, the student "e-zine" of the American Institute of Chemical Engineers (AIChE), the size and shape of the sweet spot is just another element that can be designed – within reason – into an aluminum bat. Though the durability of aluminum was what first made it attractive to college and amateur programs – wood bats just break too easily, making them very costly for these groups – its malleability, particularly when used in combination with other materials, offers a world of design possibilities that wood can't match.

Case in point is one of the company's newer products, the ConneXion bat, which promises "a larger sweet spot than any other bat design." ConneXion consists of two pieces of aluminum alloy bonded in the middle with "an elastomer connector to mechanically interlock the handle to the barrel, allowing the two pieces to act independently." In addition to a bigger sweet spot, the product offers another element that makes aluminum bats behave more like wooden ones – flexibility.

"Wood bats flex three times more than aluminum," Carlson observed. "Aluminum is too stiff. To make bats more wood-like in their feel, we needed to get away from a continuous aluminum shaft, and add something that would lower the stiffness. The rubber piece that connects the aluminum sections permits that flex."

Combining (Engineering) Strengths
Though aluminum is the mainstay of Easton products, its engineers are constantly looking for new alloys and other materials, such as graphites and other composites. As Carlson explained it, by "putting a composite, such as a graphite thermoset resin, inside the bat, you have all materials pulling according to their strength," to form "a composite structure that outperforms any of the materials taken alone." Putting composites into a product's design allows Easton to manufacture bats that are lighter in weight, and therefore easier to swing, without sacrificing strength and durability.

Finding and experimenting with new alloys is part of Brian Schwartz's job as Easton's chief metallurgist. A chemical engineer by training, Schwartz oversees the mixture of custom alloys, including aluminum with magnesium, zinc, copper and scandium, an element that, until recently, was not seen outside of Russia, where it was primarily used in missiles that could, according to Carlson, "blast through the polar ice cap."

While their product is somewhat unique, engineers in the sporting goods business are under the same constraints as those in any other manufacturing business to create a product in a cost-effective, safe and environmentally sound manner. At Easton, the latter task falls to the staff's other chemical engineer, Peter Yan. A process engineer, Yan is charged with overseeing the safe use of sulfuric acid and other chemicals essential to etching and cleaning alloys, as well as "the manufacture and use of our own custom lubricants that we make in-house." He is responsible for the reduction and management of any waste products generated in the manufacturing processes.

Switch-hitting Wood and Aluminum
With everything aluminum can do, some critics are still quick to say, "but it's not wood." For years, Major League coaches and managers grumbled about batting averages inflated by the use of the lighter, easier-to-swing aluminum bats and the difficulty of effectively evaluating college players' potential in the wood-bat major leagues. On the other hand, the NCAA, the governing body for college baseball, grew concerned a few years ago when its aluminum bat-driven offense came to dominate their games, and scores like 19-17 were not unusual.

Accepting this challenge, Easton engineers are actually working in two directions. As illustrated above, they are experimenting with new designs and alloy-composite blends to make aluminum behave more like wood. But they are also looking for ways to make wood more like aluminum. Earlier this year, the company purchased Stix Baseball, a wood bat manufacturer based in Kissimmee, Fla. Carlson indicates that, with a manufacturing unit now under their umbrella, company engineers will be looking into ways to make wood bats more durable, without sacrificing its comfort level.

"There is a market for wood bats, due to rules or sometimes preference," Carlson observed, due to "the flex effects and the tactile feedback wood gives the player."

On the other side of the coin, Easton is now working to meet more stringent design standards set by the NCAA. Carlson admitted that this is a challenge to his team, and that they "have been forced to work in other directions than pure performance." The main stipulation governs "speed off the bat."

R & D = RBIs
While there may never be a conclusive answer to the wood vs. aluminum debate, one thing is clear: Engineering does equal performance, and companies like Easton that employ engineers and let research and engineering drive new product development will probably have an edge on their competition.

"Of all aspects that have contributed to Easton's success, none is as important as the research and development Easton engineers put into every product," the R&D page on the company Web site states. It then goes on to challenge conventional wisdom about engineers by noting, "at Easton, most of the engineers are also athletes in the sport in which they innovate and design product based on their own experience. The two-piece aluminum Easton hockey stick was developed by an engineer with a passion for hockey. He developed a design that would in time become the No. 1 hockey stick in the National Hockey League."

Engineering is definitely a game-changing profession.