SpudFiles

I improved on my first copper gun design. I removed some of the chamber length to conserve on air, and I made the barrel threaded, which can now be breech loaded. Most marbles fit very tightly into the back of the barrel where the compression nut fits over it, and holds them in place.

The valve is a normal piston valve. The piston itself is made from a 3/16" threaded bolt, some washers, and nitrile sheeting, (1/8"). The exhaust valve is a 1/4" Q.E.V., which is triggered by a blowgun valve. The launcher is filled through a male auto coupling, which is shut-off by a ball valve. There is also a safety ball-valve to prevent accidental firings, after I almost put a piece of chocolate through my face with my sprinkler-valve cannon.

Here's some pictures.
And finally, destroying another perfectly good book:
Anyways, that's all I got right now. Tell me what you think.

i cant realy see the pics but the video it sounded realy quiet for a piston gun.

markfh11q wrote: after I almost put a piece of chocolate through my face with my sprinkler-valve cannon. .

i can imagine at your funeral "we pray for the soul of Markfh11q who tragicly died of chocolate-to-the-face disease "

a few questions:

• 1) how much did it cost, like what would you guess?
  
  2) could you post pics of your piston, pretty please
  
  3) how hard was it to make, like, how many hours, did it work the first time, was soldering hard.

once again i feel the alure of a copper piston cannon tugging at me.

PS, like my sexy list making?

Very nice update. It looks really good, and I sure it is fun to fill. However, was cutting the chamber down necessary? With my 1" x 60" chamber, it fills to 40 PSI after only six pumps with a bike pump... in other words, really fast. Was there some other reason that you cut down the chamber (I know you got a new compressor). Either way, it looks nice with the reduced chamber length.

@Mark: Pretty damn good - there seems to be a barrage of copper spudguns hitting the forums at the moment, and this is defininately one of the neatest built. Nice soldering.

That chocolate incident sounds like it could have been nasty.
Safety ball-valves are a big thing with me - I always have one if the design allows it. Accidents with high speed tuber are not something I want to explain at the hospital.

@A-98: Soldering isn't that difficult. Just get a bunch of cheap 1/2" capillary fittings and pipe and practise on that until you get it sorted. You pick up how much solder and heat to use quite fast.
As for time, I normally reckon on a minute (or two for a larger one) to heat each joint and get the solder properly through it.
The cooling process afterwards takes much longer though - don't rush it...

That can add up to an hour or two for a whole spudgun.

i spy with my little eye...a sick piston gun 8)
it looks awesome but it did sound rely quiet n the movie?
great gun, i to would like to see a picture of ur piston

@A-98

It cost around twenty bucks for everything I had to buy. I had a lot of stuff lying around that I used, like the Q.E.V. As for construction, it was rather simple. Soldering is pretty easy as long as you flux and keep everything clean. Here's a picture of the piston as well.

<img src="http://i43.tinypic.com/nco1hv.jpg">


@Rmich732

I cut down on chamber length to conserve air. I only get to run my air compressor when everyone's awake... which is suprisingly rare given the schedule I have for work and my stepdad's work schedule.

@Joannaardway

Yeah, the best thing I gotta remind myself when soldering is it'll all clean up in the long run, unless it's solder. You could have an ugly, multicolored joint with browned flux running all over the place, and it'll all come off. 8)


@ lukemc and experament-u2

It is a quiet gun, and attribute to the reduced chamber volume. And, those shots were only around 80 PSI.