new project and need advice on power

[beastmode986]

ok i have a few cannons im posting soon but im gonna build another one.
now i have a sprinkler valve cannon but im looking for something with more power. i fill the sprinkler valve cannon to 110 psi max and i get decent performance.However i was considering a qev or piston valve, would these be more powerful? Right now i dont own a shock pump(anyone know what store sells them in illinois?) so i can only go to 200 psi max.whats the max pressure a sprinkler valve can hold specifically a 3/8 in orbit?

what is my best opttion for power? qev,piston or sprinkler?
would a sprinkler valve yield the same power as a qev or piston valve with the exact same chamber and barel sizes etc? and finally how would i make a pump that can go to like 400 psi+? i havent seen any tutorials...

thanks in advance sorry for all the questions

[jackssmirkingrevenge]

what is my best opttion for power? qev,piston or sprinkler?
would a sprinkler valve yield the same power as a qev or piston valve with the exact same chamber and barel sizes etc?

A QEV is a piston valve you can buy. They generally can take higher pressures than sprinkler valves, though in real terms I doubt you would see a difference in performance that could be detected without a chrony.

and finally how would i make a pump that can go to like 400 psi+? i havent seen any tutorials...

Just because you haven't seen them, it doesn't mean they don't exist

http://www.spudfiles.com/forums/easy-20 ... 13264.html

If you're lazy, get a fridge compressor.

[beastmode986]

thanks. so whats the safest pressure to use a 3/4in orbit sprinkler vlve at? so bassically a qev or a piston valve is best for higher pressures right?
i was thinking about buying one. whats the highest pressure i can put in it with out it breaking?? http://www.ebay.com/itm/Pneumatic-Quick ... 3ca1f78e9c
once again sorry for all the questions these are the laste ones thanks again

[jackssmirkingrevenge]

these are the laste ones thanks again

I'm not holding my breath

Sprinkler valves generally have plastic bodies and can take less pressure safely, 150 psi is about the limit. The QEV you linked to on the other hand can be pushed to 500 psi plus without any safety fears.

[beastmode986]

Thanks for the help

[Technician1002]

In terms of power, high flow rocks. Don't use a valve with too many restrictions and bends inside. A slow to open valve provides high flow restriction for most of the shot. A fast valve can get out of the way of high flow for a high power shot.

A combination of a fast valve with low restrictions to flow provides the best power.

Long barrels such as pumpkin cannons running on lower pressure can perform well with big slower valves. Short barrel cannons will require higher speed valves.

[beastmode986]

ok so, im going to post pics and a video on my current cannon when i find my cameras sync cable... but i have a questions ive been filling the tank to 125psi max and its a fire extinguisher is that safe? Also im going to make another sprinkler valve cannon. my current one has a scope and looks like a sniper but not as powerful as i would like it has a 1/2 in barrel.I have access to a 1'' and 3/4in sprinkler valves, i want my next cannon to be more accurate and powerful. Im not sure what size barrel or chamber to use, bassically im trying to make something that looks like a sniper and has a excessivly large amount of power. So heres my problem a 1'' or 3/4'' sprinkler valve are to big for a barrel that shoots .22 pellets or 1/4 in ball bearing or any smaller ammo because of the flow restrition. any suggestions?

[jackssmirkingrevenge]

ive been filling the tank to 125psi max and its a fire extinguisher is that safe?

your tank should have a pressure stamped on it, probably much higher than 125 psi.

So heres my problem a 1'' or 3/4'' sprinkler valve are to big for a barrel that shoots .22 pellets or 1/4 in ball bearing or any smaller ammo because of the flow restrition.

Not really, a valve with more flow than your barrel is a good thing.

If you want high velocity and power from a small bore though, you're much better off getting yourself a shock pump that can take a small (say 1 or 2 cubic inch volume) chamber to 400 psi and use a fast valve like a 1/8" or 1/4" QEV.

[beastmode986]

ya but atm i dont have a qev and im not good at making pistons(im extremely bad at it) i was planning on a sprinkler valve because im not sure how to make a good piston for a qev/sprinkler valve. what size barrel would give me more power and accuracy than my current 1/2 in one? any tips on making pistons?

[jackssmirkingrevenge]

What do you want to penetrate, and at what range?

[beastmode986]

i want to penetrate umm idk 1/4 in ply wood but still have power once it exits the other side(not much just speed to fly another 20 ft or more) so basically i want to shoot through 1/4 in plywood at 50 ft+ .My goal for this project is to make something that looks like a sniper and is accurate but has alot of power also.Im thinking a 1/4 in qev with a barrel for 9mm ball bearings (maybe something smalller if i can get more power from it) then using galvanized pipe peices a 1/4 in to half in adapter then a 18in 1/2in chamber with a 1/2 in to 1/4 in adapter then a 1/4 in t and a gauge and a schrader valve. then a blowgun as a trigger. What do you think?

[jackssmirkingrevenge]

Im thinking a 1/4 in qev with a barrel for 9mm ball bearings (maybe something smalller if i can get more power from it)

In general, bigger calibre = moar powah

then using galvanized pipe peices a 1/4 in to half in adapter then a 18in 1/2in chamber with a 1/2 in to 1/4 in adapter then a 1/4 in t and a gauge and a schrader valve. then a blowgun as a trigger.

I'm assuming you're making a single shot launcher and filling the chamber with a shock pump to 300-400 psi:

- chamber is too big, 6" long is more than enough, and it also makes it easier to pump

- gauge is not necessary, there's one on the pump

- make sure the blowgun is mounted the right way round, otherwise it will leak.

[beastmode986]

ok thanks! im considering .357 pellets or .50, problem is i have to order all of my ammo because i cant buy .50 or 357 at any stores around me i dont know of any that carry them. If i were to use .50 as my ammo would a 1/2 in copper tube work as a barrel? also if i have a bigger air chamber will it give me more power?

[jackssmirkingrevenge]

ok thanks! im considering .357 pellets or .50, problem is i have to order all of my ammo because i cant buy .50 or 357 at any stores around me i dont know of any that carry them. If i were to use .50 as my ammo would a 1/2 in copper tube work as a barrel?

These won't fly straight out of an unrifled barrel.

also if i have a bigger air chamber will it give me more power?

Yes. And make it more difficult to pump.

[beastmode986]

what ammo do you reccomend? i dont know where to get an unrifled barrel