SpudFiles

This is my second pneumatic cannon. It has a ball valve trigger system. The expansion chamber is 4' long and 4'' in diameter. I fill it with a schraeder valve. There are two inter changeable barrels, they are both 4' long and one is 2'' in diameter and the other is 1.5''. I typically shoot at 65 psi but my cannon is capable of higher pressures

well nice gun! love the black paint =)
couple things though:
1. What's the purpose of the Wye you have near the valve...do you use it as a shoulder rest or something? or is it there "just cause"
2. You might want to fashion a spring or small pnuematic ram to your ball valve, to lower the opening time, or better yet go with a sprinkler valve!.
3. doesnt look like you have the best spot to shoot from, from your backyard (or where ever this picture was taken) so be careful where you point that beast!
4.you said you're using golf balls, as ammo...you might want to check out pimpmann's signature, or some hardware store and pick up some SDR-21 1.5" pvc..its a perfect fit for golf balls.

On that note, with the right barrel, and the sprinkler valve, i can shoot golf balls through a 2x4 easily with one of my cannons thats not too much larger than yours 8) (just thought i'd give an example of how great a couple little upgrades can make a cannon!)

anyways, great cannon, and happy spudding!

BOOYA
simple and powerful, me like, me like

Nice Gun.

Your chamber is a overkill, but I guess it doesnt hurt anything. Check your local pipe stores for SDR 21 and if you cannot get it, you can buy from me. GB's are defintly the way to go for power, by the way nice destruction pic. By covering the dimples your loosing performance. You can get 400% better performance with a un-wrapped ball. Proably even more considering the duct tape creates drag by its self. By all means a duct tape wrapped GB is more destructive then a potato.

istnt that wye nsf-dwv? just wondering, cause it looks it.

Absolutely Massive! Your probably gonna scare the crap out of your neighbors. I applaud you.
P.S. How much does that thing way?

I would say it wieghs in anywhere from 20-30, but that is just a guess. It is not to hard to handle considering that you shoulder it.

Looks like that wye is dwv, but what do I know.

that's huge ... like a freaking basooka or something ...

What is nsf-dwv?

it means it is not pressure rated unlike nsf-pw which is, my personal tests show that some dwv parts are safe up to 80 psi but most people reccomend 50-60 as do i if you havent pressure tested them

i have used it up to 65 psi multiple times with no problems, should that be my maximum, or would it be safe to hit 75 psi? Also i do not know if it is nsf-dwv, if there is a way to check i would like to know.

would nsf-dwv go that high in the first place?

Well I know it goes up to 65 psi so if nsw-dwv cannot go that high i guess i am not using nsw-dwv.

i have taken nsf-dwv to 80 psi without issues but its isnt rated for anything so it isnt gaurentueed. it should have pvcI or nsf-dwv if it is infact. otherwise is would have nsf-pw printed on it.