Written 10-8-19

Considering how much I liked building Lego guns when I was little, it naturally followed that I’d want to build an electric gun too. The gist of a coil gun is that a projectile is pulled toward the center of a coil. Once it reaches the center or at least some time around that, the coil is shut off, letting the projectile continue through the barrel. The timing is really important, but using a capacitor bank, which could dump its energy in a split second, made that part easy.

To charge the capacitor bank, I used the flash circuit from a disposable camera. Those things can pump out like 300v from a 1.5v AA battery. The instantaneous current through the coil is enormous, so I had to use a TRIAC to do the switching. Anyway, here’s some pictures.

To test the power, I actually made some ballistic gel but the coil gun pretty much only made dents. Here’s some videos of the coil gun firing.