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I was beginning to look down upon my coilgun after seeing other single-stage ones like this, so I decided to get a bigger capacitor bank. I'd heard rumors on the internet that you can get photoflash caps for free, if you know where to go. I tried CVS, and they handed me one. I asked for ten, and the guy had to check with his manager, who said I couldn't have any. So, I walked next door to Ritz Camera, who brought out a huge box full of used disposable cameras. He had no problem with me taking ten. Apparently they get paid $0.50 per empty camera, but if they try to charge you for them just act all nice and say it's for a school project or something.

This is based loosely off of this, but put my caps inside the box. Yes, I was able to fit all 10 in the box (barely). I have a big switch that lets me choose between 600μF (extremely dangerous) and 1120μF (insanely dangerous). It uses a standard camera charger board with the extra stuff (xenon tube, trigger coil, battery contacts) removed, so it can fit flat against the bottom of the box. Then, of course, there's the momentary charge and discharge buttons, and a safety diode for kickback if I use a coil. All of the caps are tied together with some 12-16 AWG wire, which was a big pain to solder in there. I was using 12 AWG solid copper for ground, and burnt my wrist on the wire 30 seconds after soldering it. When I was testing it, I charged it up to ~280 volts, then discharged it through a 470 ohm 1/4 watt resistor, which promptly exploded in my face. I came back after a 2 hour break, and shorted the bank with a screwdriver, and the spark still scared the crap out of me. But now it's all done, and further sparking will be carefully controlled.

I know I'm not yet in the big leagues with cap banks, but this thing sure scares me on an accidental discharge.

I would have had more pics if I had known where my camera was while I was building.

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