Semi auto bb gun.

Cole · Tue May 31, 2005 11:38 pm

What would i need to make a semi-auto bb gun that ran off of a paintball tank and had a modded sprinkler valve.

spudshot · Wed Jun 01, 2005 4:50 am

http://www.spudfiles.com/forums/viewtopic.php?t=452 a sprinkler valve is overkill for such a small barrel. and for the paintball tank, just get a regulator to get the pressure from 800psi to 100psi i hope you're not gonna shoot at people though (just a suspiscion because of the paintball tank

Cole · Wed Jun 01, 2005 5:22 am

Lol, no the reason im getting a paintball barrel is because it seems to be the most reasonable, 12 gram is too small and bulk tank is overkill. I hear you can get a paintball tank setup for 20 bucks using a beverage regulator is this true? I already have a 20 oz. paintball tank.

Cole · Wed Jun 01, 2005 5:34 am

Also could you post the parts you used for that copper semi auto, I dont quite get the loading mechanism.

spudshot · Wed Jun 01, 2005 8:03 am

sure, its mostly brass by the way, not copper.
basically inside the tee is a small spring that fits around a 1/4" tubing adapter (that horn looking thing) and that is put inside of the tee (large end of the tubing adapter toward blowgun) and when air is let through it needs to go through the smaller opening of the tubing adapter, when it does that the air hits the tubing adapter and pushes it foward, closing off the magazine (tube above the tee) and the air flows through the tubing adapter to fire the bb that has dropped.

from the blowgun to the barrel

quick connect
blowgun
1/8"npt x 1/4" compression elbow
small piece of copper tubing (the tubing was attatched to a compression fitting normally so the ring would stay in place, then the comrpession nut was taken off and put behind the ring and epoxied there so the copper tubing didnt protrude into the tee)
1/4" compression tee
inside the tee: 1/4" tubing adapter and small spring
above the tee: 1/4" steel brakeline for magazine
below the tee: small magnet taped on the outside to keep bb from rolling out the barrel
other end of the tee: 1/4' steel brakeline for barrel

and yes you can make a paintball tank set up really cheap by getting
1. universal refill adapter (goes on the tank and has a 1/8" npt outlet you screw down a pin to open the bottle)
2. a special high pressure fitting to adapt from 1/8"npt to whatever size you can find that will fit the regulator (mine has 1/4" npt threads when you unscrew the bulk tank adapter)
3. a beverage regulator, though a welding regulator may work, as long as it isnt an oxygen regulator. mine is from either an argon tank or an acetylene tank

Cole · Wed Jun 01, 2005 8:22 am

Wow thanks for all the help, not only did you answer all my questions but you did it in a way I could understand. I just have one more question for you I promise, where did you get the spring. Thank you soooo much spudshot for all your help.

spudshot · Wed Jun 01, 2005 9:36 am

i cant really help you with finding a spring, it compresses without any effort, i just have a spring box , i cut a piece out of a bigger spring for that one

Cole · Fri Jun 03, 2005 12:20 am

I found this, http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... eName=WDVW. I thought it might work as a valve for my semi auto bb gun, maybe even a timer so it could be a full auto. Tell me what you think.

spudshot · Fri Jun 03, 2005 4:28 am

hm, it would probably work, though you'd be tethered to the wall, and i dont know how fast they would reseat, they may honk like sprinkler valves do

Thai Fighter · Fri Jun 03, 2005 5:54 am

You know, you could use a valve from an old/unwanted paintball gun. Thats what i am doing for my bb gun i'm making. The valve is a little small, but you an leave it wide open if you want a fully auto. Also the air ways coming out of the valve are smaller so its easy to adapt a small tube for bbs.

Cole · Fri Jun 03, 2005 2:26 pm

Oh, it plugs into the wall?

Cole · Fri Jun 03, 2005 2:55 pm

I see, I missed the 120V thing. My bad.

spudshot · Fri Jun 03, 2005 4:15 pm

no problem, but many people set up ranges for bbmg's in their basements, so if you could do that the valve would be fine, on a side note the spring must have been stretched in mine, because the plunger doesnt want to go forward and it ends up firing in full auto or burst fire, cool effect, but it scared me when i pulled the trigger the first time

Cole · Fri Jun 03, 2005 5:15 pm

Well I want it to be portable so I am going to get a 24V solenoid valve and hook it up to cordless drill 24V battery. Yeah I think the spring will be the hardest thing to find for sure. I thought of a cool clip idea, take the 1/4 inch brakeline and bend in a spiral shape so it will hold more bbs. but still be pretty compact. The only bad thing about that is it may not have enough slope to load the bbs fast enough. Also congrats on the 1st lieutenant thing, either I didnt notice it before or you just got it.

Aaron ????? · Mon Jun 06, 2005 3:55 am

spudshot,

would i be able to make a full auto gun like yours only for the pointed air rifle pellets (i have about 500 air rifle pellets in my room)

im thinking that i would have it allmost the same exept with a rectangle shaped magazine for the pellets

also how do you straighten brakeline i bought mine in a big loop and cant get it perfectly straight??