Music boxes are awesome little mechanical devices. These days, they even make some with slightly more modern tunes, like the Zelda and Star Wars themes. But they don’t have everything, of course — certainly not that one song from that TV series that [RandomPrototypes]’ girlfriend absolutely adores.
[RandomPrototypes] started by taking the music box apart to measure the cylinder, and then created a software representation of a cylinder that’s designed to pluck the eighteen notes from low to high rather than play a song. Then he used a Python script to turn it in a 3D model. The slicing preview showed a lot of stops and starts and weak points, so [RandomPrototypes] generated the Gcode directly so that it would print in one continuous spiral and be much stronger.
In order to generate a cylinder with the song his girlfriend likes so much, [RandomPrototypes] printed this scale cylinder and used it to record the notes as a single mp3 and make note of the start times of each note. Finally, he built the new score based on the available notes built into the music box comb. If you want to do this yourself, the code is freely available. The hard part will be choosing a music box mechanism, because they tend to come with a single comb that’s designed to play a specific song. You’ll have to figure out which tune has most or all of the notes you need.
Childlike imagination is a wonderful thing. The ability to give life to inanimate objects and to pretend how they’re living their own life is precious, and not for nothing a successful story line in many movies. With the harsh facts or adulthood and reality coming for all of us eventually, it’s nice to see when some people never fully lose that as they get older. Even better when two find each other in life, like [er13k] and his girlfriend, who enjoy to joke about all the mischief their giant dog-shaped plush toy [Tobias] might secretly get into in their absence. The good thing about growing up on the other hand is the advanced technical opportunities at one’s disposal, which gave the imagined personality an actual face, and have it live inside an old CRT screen.
The initial idea was to just build a little music box as a gift, which beeps out [er13k]’s girlfriend’s favorite song with an Arduino on a speaker he salvaged from an old radio. But as things tend to go when you’re on a roll, he decided to make the gift even more personal. The result is still that music box, built in a 3D-printed case with a little piano that lights up the notes it plays, but in addition the Arduino now also displays a cartoon version of [Tobias] through composite video on an old TV. You can see for yourself in the video after the break how he goes through the day gifting flowers and drawings, and ponders about work and alternative career plans — adult problems are clearly universal.
As soon as [pashiran] laid eyes on his first hand-cranked music box, he knew he was in love. Then, he started punching the holes for his first ditty. As the repetitive stress of punching heated up his arm, his love cooled a bit. Annealed by the ups and downs of this experience, he decided to design a machine that can punch the holes automatically.
Soon, [pashiran] found his people — a community of music boxers that transform MIDI files to DXF format, which creates coordinates for CAD software. In [pashiran]’s music puncher, an Arduino MEGA takes a DXF file and bubble-sorts the jumble of x-coordinates. The MEGA conducts a trio of two stepper motors and DC motor. One stepper pushes the paper through on the x-axis, and the other moves the puncher head back and forth across the paper scroll as the y-axis. The DC motor moves the punch up and down.
Now, paired with [Martin] of [Wintergatan]’s method for chaining music box paper together, [pashiran] can write a prog-rock-length opus without fear of repetitive stress injury. And since he’s published the STL and INO files, now you can, too. Watch it punch and play 250 notes worth of “See My Vest” “Be Our Guest” after the break.
There was a time, not so very long ago, when simply getting a 3D printer to squirt out an object that was roughly the intended shape and size of what the user saw on their computer screen was an accomplishment. But like every other technology, the state of the art has moved forward. Today the printers are better, and the software to drive them is more capable and intuitive. It was this evolution of desktop 3D printing that inspired the recently concluded 3D Printed Gears, Pulleys, and Cams contest. We wanted to see what hackers and makers can pull off with today’s 3D printing tools, and the community rose to the challenge.
Let’s take a look at the top ten spinning, walking, flapping, and cranking 3D printed designs that shook us up:
It started with a cheap, punch-card programmable manual music box. Thirty-one hobby servos later, it ended as an automated MIDI music box, with a short pit stop as a keyboard-driven MIDI device.
If you think you’ve seen the music box in [Mitxela]’s video below before, you’re right. [Martin], musician, inventor, and father of the marvelous marble music machine, took an interest in these music boxes and their programming a while back. Like [Martin], [Mitxela] started his music box project with punch card programming, but he quickly grew tired of the bothersome process, even after automating production with a laser cutter. He decided to do away with the punch cards completely and devised a method to pluck all 30 notes using a few large handfuls of hobby servos. One servo, converted to continuous rotation, spins the drum, with the rest linked to small laser-cut acrylic plectrums via stiff brass wire. The fingers imitate the punched holes passing over the drum and pluck the notes according to MIDI messages. The whole thing can draw quite a bit of current, so in addition to a beefy power supply, [Mitxela] optimized the code to minimize power requirements. This had the happy consequence of reducing the latency enough to allow the music box to be played from a MIDI keyboard in real time.
A lot of work went into this one, but [Mitxela] isn’t resting on his laurels; he has a full slate of improvements that he wants to tackle, not least of which is SD card support for MIDI files to turn this into a jukebox. We’re looking forward to the updates.
[Niklas Roy] built a windmill-powered music box for his backyard, and it was so awesome all the neighbors wanted to take a picture of it. Someone even liked it so much that he stole [Niklas]’s windmill in the middle of the night. (We kind of don’t blame them, it’s a gorgeously clean build.)
In the past few weeks [Niklas] has been mass-producing 20 windmills for the KIKK Festival 2017 to be held in November in Namur, Belgium. The windmills will operate in a cluster, and all play “Für Elise” when the wind blows. However, each one is driven independently and so the music is asynchronous. Since he was building a bunch anyway, he built a replacement windmill for his backyard, and documented how to do it.
Most projects have one or two significant aspects in which custom work or clever execution is showcased, but this Music Box Hole Punching Machine by [Josh Sheldon] and his roommate [Matt] is a delight on many levels. Not only was custom hardware made to automate punching holes in long spools of paper for feeding through a music box, but a software front end to process MIDI files means that in a way, this project is really a MIDI-to-hand-cranked-music-box converter. What a time to be alive.
The hole punch is an entirely custom-made assembly, and as [Josh] observes, making a reliable hole punch turns out to be extremely challenging. Plenty of trial and error was involved, and the project’s documentation as well as an overview video go into plenty of detail. Don’t miss the music box version of “Still Alive”, either. Both are embedded below.