Inspired by Wintergatan’s Martin Molin, iSax set out to create a MIDi-controlled robotic trombone of his own. Although the aptly named RoboTrombo may not replace professional trombone players any time soon, it’s nonetheless an impressive musical hack.
The instrument is controlled by an Arduino Nano running Firmata, along with a host computer, and employs a variety of pneumatic and electrical actuators to produce the tunes.
When played, air flows through the mouthpiece via artificial lips, and turned on and off with a trumpet valve and servo. The lips can be manipulated for different sounds using a stepper motor setup. A slide mechanism is driven by a pneumatic actuator, with a linkage system that pushes it in an out, and a potentiometer provides positional feedback.
While it can’t reliably play songs on command, it’s a very entertaining project that makes a bunch of fun semi-random noises! More details on the design and construction of the RoboTrombo can be found in PDF form on iSax’s Hackaday page.