A Tabletop Demonstration Railgun
The projectiles needed to be injected into the rails with some initial velocity, to prevent
sticking in the rails. The first method was pushing the pennies into the rails using a piece of
PVC pipe. This gave very inconsistent results, so in the next design, a spring-loaded launcher
was added. This consisted of a bolt in a piece of PVC pipe, with a spring on the bolt and a
block on the end for the spring to press against. This gave more consistent results, but was
still not fast enough.
Figure 8: Spring Injector
The final injection system consisted of the PVC pipe from the spring-launcher with an air hose
leading into the back, a hand-operated valve, and a compressed air source. This gave us better
consistency and higher speed.