Picture of Drummer Wanted - Things That Think (TTT) - 2012
Drummer Wanted is a slide guitar playing automaton that will play as long as someone will play the drums for it, designed and built for the Fall 2012 Things That Think course taught at the University of Colorado -- Boulder.  There are two main mechanisms controlling the motions, one for the strumming arm and another to move the slide.  These are both driven from the same DC motor off different points from a gear box.  The input is taken from a hand drum with a piezoelectric mic affixed and sent to an Arduino.

We'll discuss the various components that made up this automaton and how it was all assembled.  Here's an overview of the pieces that make up the project.

Slide Mechanism
Strumming Arm

Step 1: Canjo

Picture of Canjo
The Canjo was built based on a simple cigar box guitar instructions found here.ri

The main modification made was to swap out a standard 1 gallon paint can for the cigar box guitar.  Since we knew we were going to use a slide this seemed like a cheap approximation of a resonator guitar.  We hoped it would provide more volume and richer sound.  

The neck is a piece of 1x2 pine from the hardware store. cut to about 24" in length for this project.  A notch about 4" is cut into one end which will become the headstock where the tuning pegs go.  These are installed by drilling three holes in the headstock and attaching with wood screws that came with them.  These tuning pegs from Amazon were used.

Two small holes were cut out on opposite sides of the paint can as close the bottom as possible.  This is where the 1"x2" is slide in.  Some wood screws hold it in place through the bottom of the paint can.  The nut and bridge can be made any number of ways, see the cigar box guitar website for ideas.  Here, metal plates which were cut down and bent to 90 degrees in a vice.  A similar technique was used for the saddle which holds the strings in place on the end of the guitar.  
This sounds unbelievable! So you hit the drums and the automaton knows to play the canjo/guitare?
danathughes (author)  Penolopy Bulnick2 years ago
That's pretty much the idea. We're pretty happy with how it turned out, given the time constraints. Glad you liked it!
Pretty dang sweet! What kind of time frame were you working under?