I don't have a lot of cash lying around, so I went as low-buck as possible, using a lot of things I had on hand already and buying what I needed as I went. Hopefully this will be a safe, reliable gun that will respond to upgrades down the line. (spark strip and stungun ignition)
I used all-black 4"x10" foamcore ABS for the chamber, ABS adapters, BBQ ignitor with dual-spark screws spaced approx 1/3-up, 1/3 down 90 degrees apart, a spare 2" CPU fan on standoff bolts in the cleanout cap, 9V battery holder with custom blue LED indicator and micro-switch, 2"x5' foamcore ABS barrel and 1.5"x5' PVC barrel. All screws and bolts are epoxied on the outside and superglued inside. I also epoxied the joints on the chamber because the cement didn't seem to do a very thorough job after drying(there were bubbles and small holes at the seams). All wiring is soldered at joints and connectors.
I'm hoping using the foamcore ABS wasn't a huge mistake, I planned on taping the combustion chamber up with a roll of electrical tape just to err on the side of safety. There was no standard PVC available locally in shorter lengths, I would have had to buy a 10' stick of 1.5", 2", and 4" pipe which adds up quick! Total cost on this was around $40 in pipe and adapters, BBQ ignitor and glue/primer. I have enough pipe left over to build another one and possibly sell off to get some cash back, heh.
Keep in mind this isn't quite finished yet, I know there's a sticker to be removed and the barrels haven't been chamfered and I haven't fired it yet...
On to the pics!
![Image](http://temp.damagedreality.com/spudgun/spudbuild1.jpg)
![Image](http://temp.damagedreality.com/spudgun/spudbuild2.jpg)
![Image](http://temp.damagedreality.com/spudgun/spudbuild3.jpg)
![Image](http://temp.damagedreality.com/spudgun/spudbuild4.jpg)
![Image](http://temp.damagedreality.com/spudgun/spudbuild5.jpg)
And one of my little gun. (shoots about 200-300 feet as far as I can tell)
![Image](http://temp.damagedreality.com/spudgun/spudgun1.jpg)