Makezine

The Quest To Make Player Piano Rolls Using lasers


I’ve found player pianos fascinating since I was a kid. The first time I saw a player piano was at the Mall of the Bluffs in Council Bluffs, Iowa, a grand piano playing away with no one around. A player piano seems like something out of fiction, a dream imagined by someone in the early 1900s of what the future would hold. The combination of music and mechanical motion is something special, and I wanted a piece of that.

I found an inexpensive piano player locally and brought it home. I fixed the electric playing function and watched tutorials on how to fix player pianos and ended up getting it working pretty well. The only problem was that I could only play the few songs that came with the piano. QRS, which has been around since 1900, is the only manufacturer that still makes and sells player piano rolls, and they don’t make very many. There were some great old songs, but I found myself wanting more.

The length of a hole corresponds to the length of a note

Each note on a player piano roll is a hole in the paper. Player pianos use suction to detect when these holes in the paper are lined up with holes in a “reader” bar. When a song starts, all the holes are covered up. Then, when a hole in the paper passes over one of the holes in the reader, it lets air through and pulls down the corresponding key.

Marking Time

My first thought was that I could use a Cricut machine to cut holes in rolls of paper for any song using the information in MIDI files. This presented several challenges. One was converting MIDI song files into images for the Cricut to cut out. I found an ancient piece of Dutch software called MIDIboek that would make MIDI files into the images I needed. 

Another challenge was that the longest paper length that a Cricut can cut is 18 inches. This meant that I had to divide up the incredibly long image file into 18-inch segments, and then cut each segment out with the Cricut. I then had to tape them all back together, being careful to cut out any holes that I taped over when splicing. I made a song this way, and it worked well. But it was an incredibly tedious process that took forever and I decided I wouldn’t do it that way again.

Isaac’s laser-based DIY piano roll cutter

I formulated a plan to make my own machine that could feed through an entire roll at once. Laser cutting seemed like the way to go, as there would be no friction from a blade. I dissected several printers and pulled out rollers and motors and chassis. I bought a little CNC controller board and designed 3D-printed parts. I had initially tried to use stepper motors from the dissected printers, but I ended up replacing one of them with a stronger, more precise motor. I had a friend use a software tool that converts MIDI files into SVG patterns meant for music boxes and fed those patterns into CNC software to send to the cutter.

Sticking Points

I haven’t gotten this new machine to cut rolls as well as the Cricut method yet. I’m having trouble with the paper starting to drift to the sides. Also, when I convert the image of the song to G-code instructions for the machine, the holes aren’t cut out in order. It ends up cutting out a few holes here, then feeding through 20 feet of paper to what would be the end of the song and cutting a few holes there. I can’t seem to find any order to how the G-code decides where to cut, which makes things more complicated. 

         I’ve enjoyed cutting new song rolls, and hearing and seeing songs that I could never play on the piano myself spring to life is a fulfilling reward. Even though I haven’t got it to work exactly the way I want, I’ve learned a ton throughout this process and hope someone else can find this information useful and interesting. Also, I’d love to hear from your experience and collaborate with anyone who could help to get this machine cutting rolls more reliably. 



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