Big or Small Fitting = Power?

[DrowningTrout]

Hello!

I made a pneumatic cannon last month to shoot 1.75" easter eggs. I found it to be a little over kill for what I needed.

(Its CO2 Powered using Kobalt CO2 System.)

Anyways I decided to make a smaller more compact version, that gets me the most bang for my buck (aka CO2 # of shots)


Here is my original setup:


Question: See how I went from the 1" Inch sprinkler valve to the 2" PVC 90's?

Will I get more power/better results by Using 2" Fittings or 1"?

(Im having a hard time explaining, if you need more explanation let me know!)

[pizlo]

I *think* you might as well go with the one inch so you can get more shots, the onlky loss is less chamber volume, other than that I *think* there would be no difference.

[starman]

You're going to lose some velocity in that fat 180 around back. It's called dead space and is essentially going to become an air spring behind your projectile.

The better configuration would be to install the sprinkler directly behind the barrel breech. The 180 becomes just part of the air tank at that point and your dead space is minimized.

[sully4]

The better configuration would be to install the sprinkler directly behind the barrel breech. The 180 becomes just part of the air tank at that point and your dead space is minimized.

Do you mean that when I make a cannon, I should have it go from the chamber, to a 90* then another 90* then to the valve, then to the barrel?

[daberno123]

Correct Sully, thats just what starman was talking about.

[starman]

Correct Sully, thats just what starman was talking about.

Thanks Dab. Yeah make the 180 section part of the tank.