Workin on my first Pneumatic cannon/launcher lookin for tips

[Northir]

Im working on my launcher, im using a quick connect and a ball valve, for direct connect to my air compressor and if i want a portable air source a female connector on a bottle cap with a 16 OZ bottle (when my bottle wears out i can replace it), the barrel is about 3/8" inside (a blow gun tube) taped to a air hose (lots of tape and a hose clamp), im not gettin the power i want using a 110 psi max air compressor, heres a picture

[MrCrowley]

Oh wow haha, try connecting the ball valve directly to the barrel. You'll still have poor performance though. Try looking through some of the pneumatic cannons in the showcase sections if you need inspiration. Plan your build, try and make a decent cannon that you can be happy with.

[c11man]

it is very..... um different? if you took your time and made even a simple piston valve you will get loads more power. they are not hard to build, mrcrowly and myself have build some pretty good pneumatics cannons and so have many of the forum members.

[Technician1002]

There is a big issue with the design depending on the volume of air that can get through the hose into the barrel. There is a limit to how much air will go through a hose. This limit limits your flow in the barrel.

As mentioned above a piston valve will make a lot of difference, but only when a local pressure storage container is located at the valve.

With a piston valve and a chamber you can expect this type of performance at lower pressure.

[suburban spudgunner]

Well... That's interesting.

For your next attempt, I would suggest a proper air chamber, to start with. Make sure you have a good C:B ratio (the chamber should have at least the same volume as the barrel; more is better).

If you don't want to mess with piston valves, a sprinkler valve would probably be the best thing to try.

And try using less tape next time...

[Northir]

not sure how to make the piston valve i just tried to search it on the site and got about twenty thousand results, a link of a simple one would be awesome also i do have a Sprinkler Valve not sure how to set it up though and if its even the right kind, again picture>

[geardog32]

it looks like a rainbird. i made a cannon with one and was very pleased. you can find many many threads on here how to modify it. look through the cannon showcase and the how to threads to get some ideas. also read up on materials because an easy noob mistake is to use dwv fittings which are not pressure rated.

edit: here is a link on modding. not sure if this is the exact valve but informative.

http://www.spudfiles.com/forums/pnemati ... 10489.html

[Northir]

Just a little update, got my Sprinkler valve setup now, trying to figure a way to attach it to the Barrel any ideas? its 3/8" inside and just over 1/2'' outside
also i have about 2 feet of hose for my air trigger, does it matter how much hose i have, i have a voice in my head yelling "less hose!"

[Northir]

For your next attempt, I would suggest a proper air chamber, to start with. Make sure you have a good C:B ratio (the chamber should have at least the same volume as the barrel; more is better).

so a im looking at a Chamber of 15/16"x2' and a barrel of 3/8"x3' that should be plenty right?

[Northir]

Well guys i took your advice, did some readin, some breakin, some building, and some swearin and Im done, here she is

[FORE!!!!]

that looks much better , and try use the edit button

[MrCrowley]

Looking alright, i'd add a barrel support to stop the bend in the barrel, probably not good for it, hose between the blowgun and sprinkler valve could also be shortened and the valve moved directly behind the barrel instead of under the barrel for better performance. The space between the projectile and valve is known as 'dead space', this hurts performance as it allows the air to expand and the pressure decrease slightly, meaning less force. In some cases it can be good for the cannon though.

[geardog32]

wow. thats a huge improvement. good job

[Technician1002]

I bet you noticed a little improvement in performance. Good job. Keep learning and your next one will be even better.

Warning, this hobby is addictin. There is always a next one. You are never truly "finishd".

[suburban spudgunner]

Damn! That's a good step up, particularly considering you did it in such a short time.

I would suggest you move the sprinkler valve, and add supports like MrCrowley said (I hate parroting, but this would improve performance a great deal).

Can't wait to see your next one (there will be more...).