HOWTO convert an MP3 to a playable, 3D printed record
Instructables user Amandaghassaei has posted a HOWTO for making a 3D printed record that plays on a regular turntable. Her method converts any digital audio file to grooves ready to print. It's a bit fuzzy, but still rather exciting! I'm waiting for the way when taking a snapshot of a vinyl disc can be the first step toward deriving its audio content, converting that back to a shapefile, and printing out a high-fidelity duplicate.
In this Instructable, I'll demonstrate how I developed a workflow that can convert any audio file, of virtually any format, into a 3D model of a record. This is far too complex a task to perform with traditional drafting-style CAD techniques, so I wrote an program to do this conversion automatically. It works by importing raw audio data, performing some calculations to generate the geometry of a record, and eventually exporting this geometry straight to the STL file format (used by all 3D printers). Most of the heavy lifting is done by Processing, an open source environment that's often used for coding interactive graphics applications. To get Processing to export to STL, I used the ModelBuilder Library written by Marius Watz (if you are into Arduino/Processing and 3D printing I highly recommend checking this out, it works great).
I've uploaded some of my complete record models to the 123D gallery as well as the Pirate Bay. Check Step 6 for a complete listing of what's there and what I plan on posting. Alternatively, you can go to Step 7 to download my code and learn how to make your own printable records from any audio file you like.