Golf ball cannon

[Juggernaut12121]

First off I have to say that this was probably my largest cannon, and my first piston gun. That being said I needed some help with design and got a lot of it from looking at similar cannons that Gun Freak and MrCowley had built.
Anyway from head to toe it's 7' 7'', it has two barrels,
Both are 5' long and 1 1/2'' in I.D. (one's a golf ball barrel)
The entire body/chamber is made from 2'' PVC pipe
The piston is just a bolt, a couple washers, and duct tape
The piston area is 2''
And the pilot valve is a 1'' modified sprinkler valve with a blowgun pilot

It doesn't work very well unless it's pressurized over 20 PSI, and I haven't gotten to shoot anything yet, but it sounds loud and feels decently powerful.

[Brian the brain]

It looks like the pilotvolume ( between the piston and the sprinkler valve) is quite huge...

That would definately effect performance.

[Juggernaut12121]

I know, I didn't think of that when I built it, I'll have to replace it with a tee going into the sprinkler and use the other port for the fill valve and a pressure gauge

[Gun Freak]

Always glad to know I helped somebody build their cannon! The chamber design is eerily similar to Superna Looking good man, I bet it's a blast to shoot. Like BtB said though, you should have just placed the sprinkler valve directly behind the piston, for more efficiency and a quicker opening time.

[mobile chernobyl]

Needs Paint! (Nice design if I do say so myself!)

My version I made a few years back as well - it was about 6-7 feet long and slightly unwieldy but FUN! Gave it to my friend who lived on a farm that had plenty of crab-apples a.k.a. perfect ammo!

[Juggernaut12121]

I've tested this a few times inside and at low pressures it sounds like a complete cannon, but I'm never able to do it outside since it's too loud and too powerful :s
The only projectile I've shot is a rag tied together with string (to keep it together) and it sounds like a brick smashed into my front door (even at only 30-40 psi) XD
I tried shooting it outside with the rag 30psi, but when I aimed down at my deck (to try and limit range) it bounced off and flew another hundred feet. I need to take it someplace bigger than my yard
I'm still not too sure what kinda paint job I want for it
Update: I finally got a suitable piece of land to shoot it on (a 3 acre strip) but it was still a little too small. The land has a hill about in the midpoint (about 30-40 feet high and maybe 40 yards long), I setup a plywood target at the base of the hill and stood 40 feet away and at 40PSI the golf ball went through the target, ricocheted off the ground behind it and flew another hundred feet or so up the hill, midway to the tree line, and into the woods
Potatoes also broke through the plywood and went across the property, over the tree line, and beyond when inclined XD (still at 40PSI)