Slingshot is an attempt to repurpose interactions normally associated to sling shots and string instruments and reimagine them as a language to control a music player device. When the motion of bending a string is combined with how the user goes about it (such as the direction and amount of distortion), the interactions are translated to actions such as skipping, randomizing, pausing and playing.

My initial concept was that of a metronome which emits music. The music would follow the tempo of the metronome. However, this idea was not so much about different types of movement by a person, as opposed to the different types of movement by the object. I decided to focus on the action of pulling something back to trigger a reaction, which lead to the inspiration (and namesake) for the project: a slingshot.

One of the main interactions I worked with was the relationship between distance pulled on the slingshot’s elastic to the distance of the object sent flying. I decided to express the short pull by having the music player switch to the next song, and the long pull be a random song, as if the force had caused the playlist to scroll through many times over.

As I simplified the design to a string strung between two poles, I began to think of other interactions which could be done. Of these include pushing the string down to pause and play, slinging your finger up and down the string to change volume, and skipping or going back a song depending on which side the user pulls back the string on (I later only focus on skipping, and pause and play).

The first prototype was created with two chopsticks stuck into a cardboard box in order to test the functionality of the sensor (the conductive rubber cord stretch sensor by Adafruit), as well as how it felt using the device. One important element for me when creating this was making sure the string was taught to provide a comfortable resistance when pulled back. It had to feel as if there was a lot of energy building up.

My original intention in the design would be a finger pad in the middle of the string, mimicking the pouch of a slingshot. I wanted the shape of the pad to physically afford being pulled back, and being pushed down. I tested different designs with some putty, but ultimately realized that it felt better interacting with the string without anything at all. I taped off part of the string with copper tape to hint where interactions were to take place.

Slingshot consists of two parts: the object itself, as well as a music player created in Processing.

 

The physical object consists of an Adafruit conductive rubber stretch sensor wound and stretched between two wooden chopsticks protruding from a wooden box. Wood was chosen not only for stability, but to also give Slingshot the feel of a wooden instrument. In the middle of the box contains a button made from a piece of chopstick connected to a mechanical switch. The whole device is operated using an Arduino Uno.