MU2301 – Making Music with Machines – A term, 2025
By Frank Santen, Aiden Cunningham, Libby Condrate, Addison Hoopes
Hurdy Gurdies are a type of instrument that actuates multiple strings by spinning a large central wheel across the strings. Our group was very interested in Hurdy Gurdies, but they are prohibitively expensive to purchase, and none of us had heard one in person before. Therefore, our goal for this project was to construct our very own mechanized Hurdy Gurdy, dubbed the “Mercury” because of the acronym HG.
Our Hurdy Gurdy was notably different than most commercial Hurdy Gurdies in several important ways. Instead of spinning the wheel via a crank that can be turned by a human, an internal stepper motor drove the wheel. The two strings on our Mercury Gurdy did not change pitch via a keybox of tangents like a normal Hurdy Gurdy, but rather by changing the tension of the strings with one stepper motor per string within the chassis. Typical Hurdy Gurdies have trompette and drone strings in addition to the main strings, but these were omitted from our design due to time and scope restrictions.
One important part of the design for us was the shape being similar to a typical Hurdy Gurdy, and somewhat matching the portability of the instrument. While the shape is not identical and the Mercury still needs to be plugged into a computer and an external 5V power supply, it looks somewhat similar and can be picked up and carried around quite easily. The chassis is made from scrap wood through a combination of laser-cutting, sawing, and sanding to achieve the desired shape.
On the more technical side, one of our group members decided that it would be good for the Mercury to work using any DAW, and not just the Ableton serial communication software that we were provided with. So, we created a .clap plugin that is compatible with almost any DAW and built our code around its use. This allows the DAW to communicate with the Arduino code and send signals from prerecorded tracks or through playing a MIDI device live.
Most of the Mercury Gurdy was built under a time crunch because the physical assembly was time-consuming and difficult to delegate the responsibility for. We ended up creating much of the planned functionality for the design, but it does not all work smoothly together. Things like the bridge height being slightly off, the wheel being just barely off-kilter, the lack of cotton on the strings, and the inexact gearing on the pitch-shifting mechanism mean that the Mercury is not a fully-functional instrument without a human to hold certain parts together and make sure it doesn’t seize up. Given more time, these would be solvable problems that we could have ironed out, but the deadline hit us before we could fully solve certain issues. Despite this, the core mechanisms remain as a solid proof-of-concept for such a device.
Videos:
Internal Close-ups:
3d Design:
Code & .clap Plugin:
Bill of Materials:
| Quantity | Item | Brand/Model/Type | Cost OR Already Obtained (AO) | Link |
| 1 | Arduino | UNO Rev3 | AO | – |
| 3 | Stepper Motor | Ender v3 | AO | – |
| 2 | Tuning Pegs | Bass Guitar | $9.99 | https://a.co/d/jgK0nmO |
| 2 | Strings | Violin | $6.59 | https://a.co/d/97J7sbx |
| – | Wood Body | Pine wood | AO | – |
| 2 | Wood Bridge | Pine wood | AO | – |
| 1 | Power Supply | Ender 23v | AO | – |