Auburn-engineered football training device has roots in tornado cleanup efforts

Inventors Vaughn Maceina, left, and Sesie Bonsi, right, worked with Auburn mechanical engineering students to create the SledHammer strength-training device.
AUBURN UNIVERSITY – Auburn University mechanical engineering students in Professor David Dyer’s comprehensive design class take good ideas and help turn them into sleek, customer-ready products. Interestingly, the good ideas can be generated at the most unusual times.

One idea, now a finished product called the SledHammer, originated when a high school football coach helped his neighbors remove debris from their yards after the April 2011 tornadoes ripped across Alabama. Vaughn Maceina, now a strength coach and teacher at Auburn Junior High School, was living and coaching in the north Alabama town of Guntersville.

“Fortunately, our community did not have any fatalities, so we were mainly dealing with property damage,” Maceina said. “I was helping cut fallen trees and then rolling the logs out of the way, when I realized this rolling motion was excellent for building strength in the arms and legs, really the whole body.

“Later, I thought about collecting some logs to try out the method, but that didn’t work because logs were not round enough. They were uneven and had knots and cut branches, so you couldn’t get a smooth motion.”

Maceina and his childhood friend, local attorney Sesie Bonsi, decided to call Professor Dyer to see if he and his students could take the idea and turn it into a training device that could be used by football players and other athletes.

“They did an unbelievable job developing our concept,” Maceina said.

Dyer and his students went to work and made the SledHammer that consists of either an 18- or 24-inch-diameter PVC cylinder attached by chains to two metal bases with free weights on top. “We wanted something like rolling a log and with variable resistance,” Dyer said.

Three groups of six undergraduates have worked on the project, with the first group working in summer and fall 2012 to make a working prototype. They did drawings, a wooden prototype and a PVC-cylinder model, followed by a full-size, metal prototype.

“We wondered how we could add variable resistance to the cylinder,” Maceina said. “The students had the idea to simply use free weights on two attached bases. The unique design allows the SledHammer to reverse directions simply by pushing it the other way as the core rolls through the sleds and goes the other direction.”

Auburn University mechanical engineering students helped inventors develop the SledHammer strength-training device.A second group of students took over in 2013 and streamlined the manufacturing process and enhanced the appearance. A third group continues to work on variations of the SledHammer as well as other new fitness products.

“The students enjoy it because there are a lot of challenges in these projects,” Dyer said. “The projects in our comprehensive design classes are very practical, real-world projects and the students get to work with industrial sponsors who need their assistance.”

Brad Martin, a 2012 Auburn mechanical engineering graduate, was among the first students who worked on the project.

“Witnessing the SledHammer project grow from a simple hand drawing to a working prototype gave me a great sense of accomplishment,” Martin said. “The lessons learned about the design process and working to meet an industrial sponsor’s needs were a great base for starting my career as a mechanical engineer.”

Maceina and Bonsi worked with Auburn’s Office of Technology Transfer to obtain patent protection and have started a company, TROUT Fitness, featuring the SledHammer. TROUT is an acronym for toughness, resistance, originality, utility and technology—and it is Maceina’s middle name.

The company has a licensing agreement with the university and has the rights to the co-owned invention. Maceina and Bonsi also worked with Auburn’s Department of Industrial and Graphic Design on brand identity, paint schemes and company logos. The university’s Auburn Technical Assistance Center, or ATAC, part of the Raymond J. Harbert College of Business, assisted with marketing and website construction as well.

“The assistance provided by ATAC and Industrial Design was crucial in helping us develop a brand identity and Internet presence to begin a plan for selling on a larger scale,” Maceina said.

Those marketing and graphic design aspects were made possible by funding from ATAC’s Economic Development Administration, or EDA, grant. “Helping existing and start-up businesses like TROUT Fitness commercialize an innovation is one of our primary roles as an Outreach and EDA University Center,” said David Mixson, director of the EDA University Center, part of the Auburn Technical Assistance Center.

Auburn High School and several other high schools and colleges are using or have used SledHammers as part of their training regimen, as are fitness companies.

In January, Maceina and Bonsi will travel to the American Football Coaches Association Conference in Indianapolis to display the SledHammer in front of thousands of professional, college and high school coaches. Maceina says the SledHammer can be customized with school colors and logos upon request and he adds that it can be used for other training programs such as crossfit.

More information about the SledHammer is available at Auburn’s Office of Technology Transfer has information on its website,,

about partnering with the university.

(Written by Charles Martin.)

Contacts: Charles Martin, Office of Communications and Marketing, (334) 844-9999, (, or Brian Wright, Office of Technology Transfer, (334) 844-7962, (