Chime Machine

Background

In our First-Year Engineering Design Tools course, each team was tasked with creating a robotic chime machine capable of playing a song at least 40 seconds long with five or more unique notes. We were limited to the provided materials—metal conduit, 1/8” laser-cut plywood, DC gearmotors, and solenoids, and no more than 50g of 3D printed parts.

Build

Our team chose to encode the song mechanically rather than through software like most others. We adopted a music-box-style design featuring twelve rotating cams on a central shaft, each actuating a hammer to strike its corresponding note. I spent over 20 hours modifying sheet music, writing a Python script to interpret MIDI data and generate a CSV file, and developing a FeatureScript in Onshape to automatically create the 3D cam geometry based on the song data. I was also responsible for most of the CAD modeling and project data management.

Result

The final product was a worm-gear-driven, music-box-style device controlled by an Arduino. It became a fan favorite at the end-of-semester showcase. My CAD professor was particularly impressed, mentioning she had never seen a student use Onshape’s FeatureScript before, and our machine was selected to be shown to future classes as an example project.