Tuesday, September 16, 2008

CO2 speargun - Mechanism

Here is a bit more on my CO2 gun and its mechanism. It is surprisingly easy to make.
I used to valves to trap CO2 from a soda stream cylinder. The size of the chamber between the two valves determines the amount of gas there is to push the spear out.

Warnings:
1.If you make yourself a gun like this remember that it can kill easily, spears or any other projectile can easily injure or destroy and possibly result in premature checkout!
2.Compressd gases can also injure and cause explosions if the user is uninformed.
3.Spearos, without a pressure guage, to may pull the trigger and watch the spear pop out weakly enough to make a large yellowtail burst out laughing at you as I experienced.





The cyliner screws into the valve at teh bottom right of teh pic, and when the valve is opened teh CO2 rushes in filling the tubes and elbows up to the next valve - this is the pressurized breach. I then close the bottom valve. The top valve is opened to fire the gun, allowing teh gas out rapidly, the gas then pushes out whatever is in teh barrel, spear, sinker, salt, fire cracker(with very recently ignited fuse) or arrow.

Let's look at my simple, yet robust, trigger mechanism:




Here is a view of the trigger valve open and discharged. My fingers point to where I had a spring that yanked open teh valve as the trigger was pulled.



To shorten the gun one could swing the cyliner under the barrel:



The muzzel, the carbon fiber was just a sticker my brother in law put on the gun when using it to impress his freinds. My motto of function precedes aesthetics is undergouing a gradual change.



The rear end of the spear and the slider. Not shown is the rubber seal I had to fit the barrel closely to prevent power loss.



Now all that remains is for me to service the gun and make a video clip of it in action...

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