SpudFiles

thanks to everyone who helped me build it. this is my first pneumatic it is about 5 feet long. please give me any ideas to make it better

there is a updated picture on page 2

Looks pretty good for a first pneumatic gun. I just don't like the silver paint on the parts, but that's just me. Am I right in assuming the ball valve between the chamber/sprinkler is to help the sprinkler seat properly or as a safety?

the only improvement I could think of is to reduce the dead space by having the sprinkler valve directly inline with the barrel, rather than under it like it is now, but no biggie.

when i first started building it the sprinkler was leaking and someone said to add a ball valve and it will work. after i added it i realized it was leaking somewhere else. so i'm just going to leave it in case i need it later.

when i first started building it the sprinkler was leaking and someone said to add a ball valve and it will work. after i added it i realized it was leaking somewhere else. so i'm just going to leave it in case i need it later.

I think they said it because when you pump up slowly, the air can leak because the equalising hole is too slow; but when all the air rushes in from being stopped by the ball valve, it decreases chance of leaking. This is all just an educated guess though, so dont take my word for it!
Nice cannon though.

Nice gun....You should use brass pipe or galvinized pipe for the gun...I would use brass pipe for the barrel because the inside of the pipe is smooth...You can get brass pipe nipples up to 3 feet long I think ,from plumbingsupply.com...The only thing is its kinda pricey..........It might weight a little more but the gun would be strong and look cool...


Kevin.B

Extra weight is always a good thing when it comes to a rifle. Ever hear of a bull barrel? If he built a wood stock and such, he could have one heck of a gun.

I like it how it is. just add a stock

I have been thinking of adding a stock. would it be easy to make out of wood?

Wood is prolly the best material to make it out of. Of course, you could always heat form PVC pipe into the shap of a stock...

nice cannon I think the silver paint is cool

I have been thinking of adding a stock. would it be easy to make out of wood?

with a band saw or scroll saw yes it will be smooth and comfortable if you use a belt sander as well, if you use a jigsaw maybe

and for your leaks submerse the gun or the most leaky part in water or get a spray bottle with soapy water then follow the bubbles, if the leak is on a threaded section you use more teflon tape of course, it its on part of a socket remove dirt and paint and don't pick up that silicon sealent junk you used on the blowgun get JBweld (or other hard solid epoxy) mix well and glob it on the leak so its at least 3mm thick and get t the proper time to solidify (its difrent based on the type you buy)

this is my semi auto marble gun. I posted it a few weeks ago but i upgraded it with a gravity feed and a scope. from 50 feet the marble will go through a 1/2 inch piece of plywood.
i need ideas for mounting the scope (right now it is hose clamped on and is very wiggly)
and i need help with what color i should paint it i might leave it the same color.

I'm personally partial to silver and blue paint jobs. I saw the topic title semi MG and I thought to myself, well, it can be a semiautomatic machine gun, that doesn't make sense.

Nice gun. When you get tired of semi auto, put a pop-off valve on the sprinkler instead of the blowgun. Then add a quick disconnect to the chamber instead of the schrader valve and have a ball valve to control the air flow into the chamber. The air will fill the chamber until the pressure reaches the opening pressure of the pop-off valve, making the gun fire once the valve pops open and the cycle completes itself over and over again making your gun fully automatic.

What type of feed do you have?

when the first marble is shot another will fall into the barrel