For our ENGR 103, we have decided to create a self-playing guitar using Arduinos. The two images below are basic concept sketches for the mechanisms that physically play the guitar.
For strumming purposes, this is the design that we have drafted up. The idea is centered around using linear actuators to move a pick back and forth over a string. The guitar pick would be attached to the linear actuator using a custom 3D printed part that we are currently working to design and a screw. The back and forth motion of the linear actuator simulates up and down strokes that a normal guitarist would use. We plan to build 6 of these guitar strummers, one for each string, so that the guitar can play notes somewhat quickly and with high accuracy since these components will not move other than back and forth.
This is the design that we came up with for fretting notes. Again, we are using linear actuators to help achieve our goal. Each linear actuator will extend to press a piece of rubber, similar to what you would find on a capo, down onto the six strings. This structures is supported by a base structure with two bars extending on either sides. The linear actuator is secured above the neck of the guitar and the rubber compressor follows the bars like a track, so that it is balanced as it is pressed onto the strings. We plan to construct four of these, which will allow us to achieve 30 notes. Having four of these also allows for faster note-playing due to the fact that they are stationary and will only move up and down.
Some links we used as inspiration: