inportb

The baby railgun was fired for the first time tonight. I was surprised that it actually worked, being so tiny. It’s also horribly inefficient. At the moment, it’s a hot rail type railgun, which means that the rails are energized before firing, and the projectile completes the circuit when injected into the barrel. Currently, I use a bamboo toothpick to push the projectile into the barrel. There’s a problem with that — because my hand is relatively slow, the moment any part of the projectile contacts the rails, that part is blown off, leaving the rest of it behind. I can certainly use compressed gas to inject the projectile, but that defeats the purpose of having a small and cheap demonstration railgun. The other choice is to use a neutral rail design, and use a switch to close the circuit. The switch would be exposed to sparks and arcs, so it would not last long.

That’s enough talk for now. On to the pictures!

That’s the whole assembly. The single AA battery used to power the device is lying around, and so are the aluminum foil and toothpick injector.

The aluminum foil has been rolled up into a suitable shape and loaded into the barrel. The injector is in position for operation.

The following are frames from movie clips of the tests.

The projectile has just completed the circuit. In a brilliant flash, it is vaporized and converted into a conductive plasma.

At the end of the shot, the projectile has exited the barrel and can be seen at the far right of the picture. It is still in the plasma phase.

Apparently, there is a quite substantial EMP generated during the shot. The camera itself was affected and the picture turned out strangely.

In this last shot, the projectile is seen just as it is halfway down the barrel.