The Vibrotron

Behold the Vibrotron! Constructed by the Carnegie Melon University robotics club, the vibrotron is a piece of a larger project called the robOrchestra. The mechanics in action here are quite simple. You have two reservoirs of small steel balls. One at the bottom, one at the top. The bottom ones are fed to the top ones using an Archimedes’ screw. Once at the top, they are dispensed through some tubing down to plink off of a vibraphone key. All of the timing is done via solenoids mounted at the end of the tubes. The final product reminds us of the Animusic animations that were put out a few years ago.

For this system, since they wanted this to be an automated and reconfigurable bot, they are using an Arduino to control the solenoids. This way they can change songs as they please. We have to admit though, we’d love to see one where the timing for the song was all done through tube length or some other passive system allowing it to be hand cranked and purely mechanical.


[via Make]

18 thoughts on “The Vibrotron

  1. I would think that the tubes are full of the balls as much as possible and the thing in the end of the tube is a solenoid controlled “valve” that let’s off one ball at a time.

  2. Sounds like the screw adds too much noise to hear the music properly. I’d like to hear what it sounds like with that part off.

    Maybe they could change the shape of the bearing reservoir to isolate the screw from it, unless that wave action is there to keep the bearings from getting stuck in the hopper.

  3. We’re experiencing the same effect as not sitting in the “sweet spot” for a marching band. If they were to mic it in the center above this particular instrument, it would be more discernible. That doesn’t fix the noise, but this is still a very impressive concept (especially in light of the bigger picture). Kudos to CMU Robotics.

  4. crappy recording with “auto-leveling”. they need to set the recording level manually beforehand, else it will amplify the random noise whenever theres a tiny bit of relative silence.

  5. Those are Vibraphone keys. The worst thing you could possibly use to play those is metal. It would sound much better if you could get your hands on some rubber instead.

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