Robotic musicians are nothing new — we’ve all seen Compressorhead, The Trons, and Shimon, each having their own different playing techniques, instruments, and styles. The drive for great robot musicians has continued to spur development among academic institutions and makers alike. One of the latest I’ve come across comes from robotics enthusiast Clayton Darwin with his mandolin-playing delta robot.
Darwin’s designed his delta robot using a pair of NEMA17 UniPolar stepper motors, two H-bridge modules, an ESP32 module, and two wooden arms connected to a guide frame that performs the picking motion. He states that his robot is still undergoing development, so the actual makeup of his design is limited in details.
From what I’ve seen in his project videos, the ESP32 controls the H-bridges via varied step counts for each motor based on the song being played. For example, the top will articulate at a different speed from the bottom to facilitate plucking the correct note on the mandolin without inadvertently hitting any other string in the process.
An earlier version of the robot shows it was only capable of down picking only, limiting what songs it could play; however, his latest shows it can now perform both upward and downward strumming, allowing it to play more complex tunes.
Darwin mentions that he’s still working on the robot’s mechanics and programming (uses MicroPython) and hopes to add some O-rings to act as dampeners and bearings to the push rods so it will lessen the buzzing while playing. It seems after each upgrade; the delta robot is capable of playing new songs, it will be interesting to see what songs it will be able to play on its next evolution.