A Tabletop Demonstration Railgun

Intro Theory Construction
Power Source Rails Projectiles Injection Our Results Go To
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Building a railgun is not as simple as it sounds. There are several problems associated with physically building a working railgun. First, a large enough current pulse must be applied to produce a reasonable amount of force. This large current tends to damage the projectile and the rails. This current also produces large forces in the wires carrying it (due to the same electromagnetic forces pushing the projectile), pushing the wires apart with great enough force to bend, break, or launch them.

Here is a picture of one of the conductors we used to connect the capacitors in parallel. This previously flat copper strip was bent by the electromagnetic forces.

Here is the crimp lug on the end of one of the wires carrying the current from the capacitor bank to the rails. It was stretched out by the electromagnetic forces.

The force on the conductors connecting the capacitors together and the cap bank to the rails was one important consideration that we didn't allow for. Large stress was placed on the terminals of the capacitors, damaging some of them. A better design would allow for these stresses and not put sideways force on the cap terminals.