Interesting device built from a Sherline 5400 tabletop milling machine…information on a a portable, battery powered, electromechanical projectile launcher the author designed and built. It is a type of “centrifugal” launcher powered by a DC motor. The launcher fires primarily plastic spheres (or steel with some modifications) semi- or full- automatically that is more powerful than a typical airsoft gun. No compressed air or any other energy source besides the battery pack is needed to power the launcher, so it is capable of sustained full automatic fire. The device is called a “PEST”, or Portable Electromechanical Slug Thrower for short. *grin* The PEST has the following specifications… Link.