I wanted to do a mini project with the BeagleBone Blue that would utilise all of its servo capabilities. So I came up with the idea of a mechanical glockenspiel.
There was not much to the mechanical aspects other than the brackets that were designed in OpenSCAD and 3D printed. The beaters were old lolly sticks with some simple wooden balls glued on the end. I attached those to the servos using rubber bands. This was to avoid overloading the servos if the beaters crashed into the glockenspiel and to give a bounce to the motion when the servos moved. The current demands of the servos caused me a bit of an issue so I built an adapter that would allow me to power those independently from the BBBL. I also wrote a bit of driver code that allows the servos to be controlled without the need for root access.