Students engineer robotic chimes

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Michelle Cometa

Mechanical engineering students put the finishing touches on robotic chime machines they built during the fall semester as part of an Engineering Design Tools course.

Recording artist John Mayer may not have intended his composition “Gravity” to be played on chimes, but the rendition created by undergraduate engineering students came very close to the original tune.

Armed with a mixed box of parts and equipment—from sensors and gear motors to bamboo sticks and metal piping—teams of students from an engineering design tools course in RIT’s Kate Gleason College of Engineering were asked to design robotic chimes programmed to play recognizable songs.

The project was more than putting together a few pipes.

Students had to determine acoustical frequencies, build three-dimensional computer-aided design, or CAD, models of the chime structure and test the end product’s mechanical function as well as song quality. Over the semester, the students were able to learn about, and apply, foundational engineering concepts and techniques, such as moments of inertia and frequency domain analysis, they would use for subsequent undergraduate coursework.

And it was also a chance to make good music.

“We brainstormed song ideas and decided on “Kids” by MGMT because it’s so distinctive,” said Evan Mori, a first-year mechanical engineering student from Latrobe, Pa. Once the song selection was made, there were multiple steps in the design process. Mori and his teammates, Alaysia Gilbert, Brenna Lewis and Collin Cragon, predicted the length of each pipe needed for their song based on a theoretical model of beam vibration, their measurements of pipe diameters, and estimated values for the pipe’s material properties.

“They’d hit the pipes, measure the sound, look at the frequency spectrum, and see how close they got to their original prediction,” said Mario Gomes, assistant professor of mechanical engineering.

Gomes worked with Elizabeth DeBartolo, associate professor of mechanical engineering, to devise the overall project concept for the new class as RIT transitioned from the quarter system to semesters. The class is an opportunity for students to learn the various elements necessary to design and manufacture a new product prototype. It is a required course for all RIT’s engineering students and involves not only learning the design process, but also about project management and team communications.

“When we re-organized the curriculum for semesters, the mechanical engineering faculty thought it would be good for our students to have a course that combined CAD, machine shop and also, for the first time, an introduction to design, at the freshman level, as we hadn’t had that before,” Gomes explained.

At the start of the class, the goals and constraints for the design problem were given to the students, and the teams began brainstorming structural options and sketching their ideas.

Gomes provided each student team with an identical kit of parts consisting of common electrical conduit, lumber, popsicle sticks, adjustable DC gear motors and switches. Gomes and graduate student Konrad Ahlin designed and built custom electrical test boxes.

Although each team was given an identical kit of parts and the same goal—to play a recognizable song with at least five different notes—designs varied widely. Some were elaborate, tall structures with pipes in the center; others were flat, boxed designs with clappers running across the different pipes in sequence.

Mori’s team chose a pulley system to move the clappers along the main structure: “It seemed the most reliable of the process choices, especially for our song.”

Songs included seasonal classics such as “Christmas Bells” to favorites like “The Pink Panther” theme and “Keyboard Cat.”

“Ours was semi-complicated, but we have 10 notes,” said Lucas Jackling, with a laugh. The second-year mechanical engineering student from Fillmore, N.Y., enjoyed the experience of working in teams and getting a chance to understand the latest technology.

Note: This course was taught through a team approach with several mechanical engineering faculty and staff participating with Gomes: Marca Lam, mechanical engineering lecturer, taught the CAD component; Jan Maneti, Rob Kraynik and Dave Hathaway instructed the machine shop lab component on how to safely operate machine tooling and fabricate parts from drawings.

Mechanical engineering students put the finishing touches on robotic chime machines they built during the fall semester as part of an Engineering Design Tools course. Michelle Cometa