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Posted: Wed Dec 05, 2007 4:17 pm
by CarriageGuy
Nah, this is complicated enough for me.
The rest of the family is just building the old fashioned basic models with a ball valve, mine is uber high tech compared to theirs, and i dare say should propel the ammo MUCH further
Just to give ya'all an idea, here's the specs:
Barrel: 3'-6" long sch-40 grey electrical conduit 2.5" I.D. (it's what i had laying around)
Tank: 2'-5" long white sch-40 pipe 4 inch I.D. (happened to have that laying around too, as you will see by the dirt on it when i post pics)
Then of course there are the reducers on each side of the valve that i *hope* and pray wont make any noticeable difference to performance.
I like to go big, i just dont have a lot of $$$ to spend.
NOW, stupid question; how well will that 2 and 1/2 I.D. pipe work with tennis balls?
The three inch pipe was too big, and the 2 & 1/2 seems real tight, so i am going to make a tamping rod of course, but with it being that tight a fit, will i have to watch out for stress on the barrel?
Tom
Posted: Wed Dec 05, 2007 4:19 pm
by ShowNoMercy
The barrel will be fine, with a burst pressure of upwards of 300 psi but what you want to worry about is the moment put on the reducers and valve. They are they weak points because they will shatter with side to side forces. But I think you should be fine.
Posted: Wed Dec 05, 2007 4:20 pm
by CarriageGuy
ShowNoMercy wrote:
Sorry, I was just voicing the way I would try it. How about a ball valve with a string attachment so you can pull it open from a far? That would go with that time period too.
No problem, i am always open to suggestions...
SPEAKING OF WHICH... i like the idea with the string.... is there a way to *mount* the blowgun to the side of the barrel and attach a string to it somehow that the kids could pull??? That would be awesome!

Posted: Wed Dec 05, 2007 4:23 pm
by ShowNoMercy
Forget the blow gun, you know what a ball valve is? Get a 1/4 inch one and some nipples, and rig it so the ball valve is attached firmly to something and then have a string hooked up so that it will be able to open the valve fully. The only downside to this is that you wont be able to have the cannon hooked up to a constant air source, aka you need to close the ball valve after every firing and then charge the cannon up.
Posted: Wed Dec 05, 2007 4:24 pm
by CarriageGuy
ShowNoMercy wrote:The barrel will be fine, with a burst pressure of upwards of 300 psi but what you want to worry about is the moment put on the reducers and valve. They are they weak points because they will shatter with side to side forces. But I think you should be fine.
What about using some kind of "lube"

on the inside of the barrel?
(ok ... quit laughing guys, i'm serious!)
Posted: Wed Dec 05, 2007 4:26 pm
by ShowNoMercy
I really don't think thats needed, I used to have one and I never had a problem with it. To load it I had to use a broomstick and hammer to jam the ball in. Now about the other stuff, what is your cannon gonna look like?
Posted: Wed Dec 05, 2007 4:32 pm
by CarriageGuy
ShowNoMercy wrote:Forget the blow gun, you know what a ball valve is? Get a 1/4 inch one and some nipples, and rig it so the ball valve is attached firmly to something and then have a string hooked up so that it will be able to open the valve fully. The only downside to this is that you wont be able to have the cannon hooked up to a constant air source, aka you need to close the ball valve after every firing and then charge the cannon up.
sorry man, already got the rainbird all glued in.
from what i read all night last night on the boards, evryone said to go with the blowgun, so i did.
So lets work with what i got already installed and see what we can come up with.
As for what this thing will look like, it should look SOMETHING like this....

Posted: Wed Dec 05, 2007 6:42 pm
by CarriageGuy
Posted: Wed Dec 05, 2007 6:58 pm
by BigGrib
congrats you have just modded your first valve, now all you need to do is epoxy, in the pics of the bowl # 2&3 the tiny hole off to the right hand side, that is your solenoid pilot hole, epoxy that little guy up, and hell you can even put the solenoid back in. once again congrats and good job man welcome to the modded sprinkler valve club
Posted: Wed Dec 05, 2007 8:26 pm
by ShowNoMercy
What i was saying above was to use to ball valve to pilot the solenoid valve, which you modded nicely.
Posted: Wed Dec 05, 2007 8:51 pm
by CarriageGuy
ShowNoMercy wrote:What i was saying above was to use to ball valve to pilot the solenoid valve, which you modded nicely.
OH!!! Now i understand!
Put a small ball valve at the end of the hose! duh.
Posted: Wed Dec 05, 2007 8:55 pm
by ShowNoMercy
Thats what I meant! What do you think ?
Posted: Wed Dec 05, 2007 9:09 pm
by CarriageGuy
Is there such a thing as a flush mount ball valve that i could mount to the outside of the shell tube with screws?
Posted: Wed Dec 05, 2007 9:11 pm
by ShowNoMercy
I bet you could find something like it, and how about a boiler blow off valve. Home depot has them, they are a flip open type valve you use to drain your water heater.
Or sorry why not use a saftey blow off valve ? That way all you need to do is tie a string to the pin and pull, and it reseals! Granted it wont flow all to great but it would most def work.
Posted: Wed Dec 05, 2007 10:42 pm
by BigGrib
I don't think a ball valve would be that easy to open with a string, might pull our aim off a bit, i think if you were to use a blowgun, you could easily wrap a string around the deal and pull it nicley and you wouln't have to use that much hose to reposition it, probably only a couple of feet. the water heater safety valve might work but the restriction and excessive pilot volume would be really inefficent