SpudFiles

This is basically a simple sprinkler valve launcher I made for my AP Physics class...

2 inch chamber
1 inch modded sprinkler valve
3/4th inch barrel
1:1 C:B Ratio
Threaded Schrader Valve

I decided to shoot corks (they seal perfectly) because they aren't too dangerous and wouldn't go through the back board (1/2 inch plywood).

Anyway, here it is - simple but very effective.

Cool, Its basic but it probably has decent preformance for a sprinkler valve, my only suggestions would be to paint it and add breach loading

I would love breach loading... how do you do it?

Breech loading.. A couple of choices.. Pick one.

A ball valve with a hole cut in the side;
A port in the breech with a sliding repair joint to cover the hole
Removable barrel with spud cutter breech
Another design.

Example of the sliding coupler is shown below.

[youtube][/youtube]

For a 3/4" barrel it is easy to make a breech load in 1.25 in pipe. Have a look at Lockednloaded's sprinkler valve gun, it uses one, also my gun has one but I didn't post it.

edit, randomly saw the link,
http://www.spudfiles.com/forums/bolt-ac ... 21023.html

I would recommend a breech load and a cover for the blowgun to make it more comfortable. If you have any questions regarding my breech load linked above, PM me or ask ITT. Since you are shooting corks ATM, it wouldn't be hard to cut up a few and use them as sabots for some more destructive ammo. All in all, its a good clean cannon; you've obviously done your homework on his one

Thanks guys...

I have a bigger piston valve cannon to shoot the real destructive ammo, this one was mainly made as a relatively safe one that I could bring to school. I actually have used the corks as sabots though - I shot a piece of re-bar through 1/2 inch plywood, and it's really fun to shoot cherries and rocks...

Haha I sure hope I can build this sort of stuff in high school! It's the simplest ones that are always the funnest right? I mean big piston valve launchers are a lot of work.... but still they're pretty awsome too.

Once you upgrade to pistons there is no turning back.

Im a little late replying but to make a breech loader you could
A-Sand down a coupler the size of the pipe and cut a hole in the barrel
B-Use a Repair Coupler
C-Use a ball valve with a hole cut in the side

I don't agree with the repair coupler idea because it will make too much airloss out the breech load, I think the best way to go is the one like LnL's because there is no air loss.

to be fair, there is a small amount of air loss due to sloppiness. If i put a gasket in the coupler, it would be air tight. I may do that though, on another cannon

and also, IIRC, repair couplers have o-rings

I modeled a 3/4 breech loading barrel after yours and the 3/4 piece of pipe goes into the coupling pretty far but it's enough to almost prevent air loss, yeah theres a little, but it isn't noticable on mine...
About the repair couplings... the 1.5" ones I got at Home Depot didn't have o-rings, they just slipped right over the pipe....