WPI Student Combines Interest, Skills and Academics to Build Exercise Machine

Contact: Neil Norum, WPI Media & Community Relations

John Tassinari is shown with his cable crossover exercise machine in the WPI Fitness Center

Worcester, Mass. -- To the uninitiated, the rectangular steel framework of the Worcester Polytechnic Institute (WPI) Fitness Center's newest exercise device might look like something a kid put together with an Erector(tm) set. But the muscular athletes who make working its weighted handles seem as effortless as pulling taffy know that it's a cable crossover machine - and a welcome addition to WPI's increasingly impressive array of fitness equipment. What makes this machine remarkable is not that it's something unique (most gyms have them), but that it was designed and built by a WPI student as his Major Qualifying Project (MQP).

Manufactured by several fitness equipment companies at prices that can range from $4,000 to $8,000, cable crossover machines can vary significantly in quality and design. As a certified personal trainer, John Tassinari, a senior majoring in mechanical engineering from Braintree, Mass., knew firsthand how a poorly built machine could upset an athlete's concentration. As an engineer, he understood how they're constructed and what makes some of them superior to others - and he knew he could build a better one for less money.

"Cable crossover machines have two weight stacks, one on each side, and usually have four handles," explains Tassinari. "By changing attachments, a person can work every muscle group. Because they are so versatile and are used by so many people, they should be among the best-made pieces of equipment in any gym or fitness center."

But that's not always the case. "Most companies make their machines with thin-walled tubing, arranged in less-than-ideal configurations," he says. "Thin-walled tubing has a lower cross-sectional first moment of inertia that makes it easier for the tubing to bend; when the tubing bends, the machine feels flimsy and unstable. Another problem is that moving parts are rarely designed to minimize friction. The pivots are isolated from the frame using bushings, not bearings. Since bushings produce much more friction under load than bearings, they can make the motion choppy and stiff and cause the device to feel unsafe. And if the machine feels unsafe, users can't fully concentrate because they are worried about its structural integrity or because the motion simply does not feel natural."

During A-term Tassinari used Pro/ENGINEER computer-aided design software to redesign and model a new cable crossover machine with a stronger, more rigid frame and components that move with minimal friction. In the following weeks, he drew on his strength and stamina as well as his engineering expertise as he turned the raw materials he unloaded from the supplier's truck into the machine he'd described in his MQP report. "I worked about eight hours a day welding and machining the parts throughout B-term," says Tassinari, who estimates that his design could be manufactured for about $1,500.

"John did an excellent engineering job from start to finish-design, analysis and construction," says Tassinari's MQP advisor, Eben C. Cobb, visiting assistant professor of mechanical engineering. "The identification of a problem is always the key step in engineering design and John did it very well."

The Fitness Center purchased it at cost and installed it in January. A plaque in the upper right hand corner identifies Tassinari as the builder. Faculty, staff and students who completed a survey after using Tassinari's machine indicate that it is stronger, more rigid and smoother than existing devices.

John did a tremendous job constructing this piece of equipment," says Matthew Ballard, Fitness Center supervisor. "It is without question one of the best fitness machines currently in the center. This is certainly an MQP that all members of the community can benefit from."

Tassinari is the son of Paul Tassinari and Dawn Goodrich of Braintree, Mass. He is vice president of the WPI chapter of Tau Beta Pi, the national engineering honor society, a member of Pi Tau Sigma, the mechanical engineering honor society, and comptroller for the WPI Weights Club.

WPI, a technological university, is renowned for its project-based curriculum and its overseas global perspective program. In the 1999 U.S. News & World Report's edition of America's Best Colleges and Best College Values, WPI is ranked among the top national universities.