A rail gun is a gun which uses projectile kinetic energy instead of chemical means such as gun powder to propel an object.  The rail gun uses an electromagnetic force called the "lorentz force" to propel a electrically conductive object which is initially part of the circuit. The current which flows  through the rails builds up a magnetic field between them.  The conductive projectile doubles as a switch, gapping the space between the two rails completing the circuit.  This results in a  repulsion of the rails against the projectile and the acceleration of the projectile along them.

In the big picture, a railgun is even simpler to build than a motor. It consists of two  metal rails connected to an large capacitor bank. Then a conductive projectile is inserted between the rails from the non conductive end (which acts like an initial platform). Compressed air is then forced down the rails behind the projectile. This pushes the projectile onto the rails and also adds speed.  Now the projectile completes the circuit.  Electrical current runs from the positive terminal of the power supply up the positive rail, across the projectile, and down the negative rail back to the power supply again.

This immense blast of current makes the railgun act like an  giant electromagnet, creating a powerful magnetic field in the region of the rails and the projectile.  Since the current flows in opposite direction along each rail, the net magnetic field between the rails is directed vertically. Now the current  flowing across the projectile,  produces the Lorentz force which accelerates the projectile along the rails. 

Basic Rail Gun Set-up

Rail Gun Test Fire (Projectile Distance : 3 feet)



(coming soon) (799kb)












  • Micro Rail Gun
  • Mini Coil Gun One
  • 90 Joule Coil Gun


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