There was a certain amount of satisfaction seeing the pickups fit nicely into their case. After some discussion as a group we proceeded under Ed’s guidance to modify the design further in Fusion 360. A bench was added for the pick along with reinforcements for the two end boxes. Ed took the reigns and transformed the design further quite considerably. Rails we added to the base of the device for additional support. It was decided that this was needed to support the device when the strings were tightened. A long bench was added across the device, along with a bridge for the strings at ether end.
Barry, keen to explore the musical capabilities of the device, managed to power up one of the prototypes. Using an exploratory approach akin to circuit bending Barry found an interesting feedback effect. Barry tried a few different potentiometers, salvaged from a box of scrap components, for controlling the feedback amount. These potentiometers were of various values and from different manufacturers. What was particularly interesting was that they all had different sonic qualities. Barry chose a favourite and then this was factored into the design.
Ed suggested creating a tremolo effect through the use of an LDR. This was coupled with a spinning disc, also laser cut MDF, which blocked out light at certain intervals as it rotates. The motor was controlled by a Teensy microcontroller. Ed introduced me to the new touchRead() library available for Teensy. A clear example is described on the little-scale blog. The touch pads themselves were etched from a copper circuit board and mounted on top of one of the side boxes of the device.
To complete the digital fabrication picture, Ed talked us through using a CNC machine to mill a piece of solid wood which would be used to support the tuning pegs of the strings. A drawing was made in Autocad of the basic shape. Ed then used Corel Draw and printer driver CAM software to determine drill paths, set the number of passes and the depth of each cut.
Unfortunately, despite working into the early hours of the morning, we didn’t manage to finish building the instrument. We were able to take all of the parts home with us however. Now it’s just a case of putting aside some time to complete the build. All in all it was a very enjoyable week, and I certainly learnt some skills which will help me with my research.