Custodial staff in Howard County schools ran into a problem last year when the handles on several floor buffers began to break and the manufacturer discontinued replacement parts. Rather than buying new buffers, however, the staff got help from Reservoir High School junior Christian Michael, who used reverse engineering and 3-D printing to successfully design improved parts, with guidance from technology education staff.
Using ABS plastic, commonly used to make water bottles and children's toys, 15 sets of the three floor buffer handle parts were 3-D printed at roughly $22 per set and a total cost of about $330, saving the school system thousands of dollars, according to technology education teacher Daniel Rosewag.
Now, whenever the original parts of the floor buffers break, Rosewag said, the blueprints for replacements will be sent to the school's 3-D printer to create improved handles.
Jeremy Dyer, the school system's former maintenance manager, said custodians across 13 schools reported handles breaking on the Nobles Ultrashine model floor buffer. Fifteen machines broke no more than two years after purchase from Minneapolis-based Tennant Company, he said, which were all purchased between 2003 and 2013.
A technical support spokesman for Tennant said only 17 complete handle assemblies are still in stock since the part has been discontinued. They declined to comment further on the floor buffer issue.
Dyer and Reservoir High's head custodian Monroe Graham presented the task to Rosewag and two other tech teachers, David Burke and David Walley, who recommended the 16-year-old student engineering enthusiast for the job.
"Christian not only reverse-engineered the part so that we could perfectly replicate it within a 3-D printer, but he also identified a flaw in the part, which is where the part was continuously breaking," Rosewag said. "We beefed up that part, printed a number of sets for the county and to our knowledge, none of our parts have broken at this point."
The three teachers work in the Career and Technology Education Department, where they first met Christian in a pre-engineering class as part of the Engineering: Project Lead the Way academy program. The national program introduces engineering to high school students through mathematics and science, and provides each Howard high school with a 3-D printer for specific courses.
During his classroom instruction, Christian showed "outstanding abilities" when they began using the 3-D modeling software in an introductory assignment, Burke said.
"When the [floor buffer] project was brought to me, he was really the only student I had who had had enough experience, and I knew he was very engaged with the software," Burke said. "With Christian, he will give 110 percent to everything he does."
The course also introduced reverse-engineering, he said, which requires a backward way of thinking as engineers break down a product and piece it back together, while improving its overall function. Rosewag said rival companies often use the process when they try to replicate products and add their own features to avoid copyright infringement.
"[The process] includes the tensile strength of whatever the material is all the way to the specific measurements of whatever the item is," Rosewag said. "If you're talking about something that's electronic, you're going to look at how the various electronics work within the product."
Sitting over his design journal at a classroom desk, Christian lined up two sets of floor buffer handle parts, one unbroken set provided by the Tennant Company and another set made of white ABS plastic. The North Laurel resident said he was given the original three handle pieces to review and then used a dial caliper tool to measure the thickness, width and length of the each piece to replicate the parts before tinkering with its effectiveness.
During his evaluation, he said he noticed a weakness in one of the three parts that may have contributed to the breaking.
"I noticed that on one section on a piece that always snapped, there was a gap in the middle and it seemed very flimsy," Christian said. "For me, it's not so much challenging as it is satisfying to know that I'm creating something close to a replica and comparing them."
For two weeks, Christian spent his lunch breaks designing replicated replacement parts for the floor buffers, Rosewag said, but making slight adjustments to its durability.
Graham, the head custodian, said he was delighted about the tech department's quick turnaround for a possible fix to the ongoing problem.
"When they said they had a student working on it, I was like, 'Sweet!'" Graham said. "Once they had blueprints of the piece that we were going to make, we could send it to other schools if we needed to and have them print some as well. … They actually saved the county a lot of money because without that part, we would've had to replace the machine all together."
Christian's dedication to problem solving benefited the outcome of this project, said Walley, who saw his student's interest in engineering and mechanical drawing during Robotics Club gatherings.
"Here at Reservoir, we really try to teach those real-world application skills," Walley said. "He took it and ran with it and I couldn't have been happier with the outcome."
Describing his own work ethic as "passionate and driven," Christian said he hopes to become an aerospace engineer and learn more about the process of reverse engineering.
"I was … surprised [it worked] because I was expecting that I'd need to change around a few areas for it to successfully work. The whole time I was thinking, 'I have to get these to work,'" Christian said. "I'm very passionate about technology and science. I would consider this project as a mini hobby. It was very interesting."