[Yannick], aka [Gigawipf] brings us this (mostly) musical delicacy: a 3D-printed siren that’s driven by a brushless quadcopter motor, and capable of playing (mostly) any music that you’ve got the MIDI score for. This is a fantastic quickie project for any of you out there with a busted quad, or even some spare parts, and a 3D printer. Despite the apparent level of difficulty, this would actually be a great quickie weekend build.
First stop is Thingiverse, for the Mini Air Raid Siren model. Start that printing and get to work on the electronics. For the MIDI-to-ESC (electronic speed controller) conversion, any Arduino with USB support (ATmega32u4 or ARM boards) will work. The important bit is that you can run the MIDI-USB library. All that remains is a MIDI-to-servo pulse conversion and lookup table. Here’s [Yannick]’s file, but we’re guessing that you’ll want to tune your own siren.
How well does it work? See the videos below. Short notes, as well as note-offs, tax the quad motor’s ability to stop the siren rotor immediately. There’s a nice portamento effect as it ramps up between notes as well. You’ll need to pick your repertoire accordingly.
We have a strange affinity for musical sirens, so we’ll readily admit that [Yannick] had us at the word “spinning”. This is an easy project, with a pretty cool result. As far as we know, there’s only one 3D-printed, MIDI-controlled siren in the world, but it shouldn’t be hard to scale the siren model up or down to make different registers and effects. So who’s up for an entire symphony of these things?