When we think of a xylophone we envision hitting the keys from above with mallets. But this robot instrument launches stones from below to play a tune. [Niel] calls the device a Pinger and it is part of a Rock Band — all instruments using rocks.
Although the original post has “xylophone” in it, this musical instrument is technically a glockenspiel because it uses metal keys instead of wood. Either way, it’s a work of art; the instrument’s creator ([Neil Mendoza]) was participating in
Adobe’s Autodesk’s Pier 9 artist-in-residence program when he built it.
The keys were cut using a water jet, a process not easily in reach for most of us. But you could make do with a different process in a pinch. On the face of it, fabrication seems simple, but there’s software to calculate the right size for the keys depending on the material. The cuts need to be precise to yield an in-tune instrument.
The circular part is laser-cut acrylic, acting as a base for each key. Below the plate there is a cylinder positioned in the middle of the bar which keeps the stone from getting away. When the solenoid fires, the stone flies up and strikes the key, creating a ringing tone but also adding to the body of sound with a rattle when it falls back down to the base. The entire thing is driven by MIDI, so it can play a lot of tunes besides the biographical “Here Comes the Sun” (since, apparently, the pebbles are out in the sun). Check that out in the video below.