Design of repeating projectile toy based on bistable spring propulsion

Abstract

Recently, bistable springs have been proven as a viable propulsion method for the standard 1.75" foam balls used in Nerf® projectile toys. This technology was developed at M.I.T. by William Fienup and Barry Kudrowitz, who designed a single-shot hand-popper that utilized a large bistable spring. The goal of this research was to design and develop a projectile toy capable of safely firing multiple foam balls in succession, using this novel propulsion. A structured design process was followed and this toy, the shot-popper, was brought to the alpha-prototype level. Largely this project was a success. Between the shot-popper, and the flat model that came before it, every module of the toy was shown to function as desired.