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Rapid fire ball valve

Posted: Sun Mar 11, 2007 11:19 pm
by shud_b_rite
The bestway to make a rapid fire machine gun is to have a it hooked up to a large compressor because they have such high air consumption. So here's my idea that will allow you to make a rapid firing gun that you can use with an average sized chamber.

A ball valve is simply a ball with a hole through it. The ball is turned 90 degrees to allow the air to flow through the hole and then turned back to close it off.

If a ball valve could be modified to turn a full 360 degrees and a battery powered motor could be attached to it, then BAM! you have yourself a rapid changing valve. I have never built anything that shoots more than one shot but I reckon it could work. The speed of the motor would have to be tuned to get the best performance.

I dont have any ball valves handy that aren't attached to something so I havent had the chance to pull one apart to modify it.

Im not sure if anyone has ever had this sort of idea before, I did search the forums but there are so many keywords that all lead to the same thing so if it has been done before the MODS can delete this post.

Anyone else think this could work?

Posted: Sun Mar 11, 2007 11:30 pm
by homedepotpro
that has some potential,
like civil war gatling guns, with a big cranck turning the ball valve

Posted: Sun Mar 11, 2007 11:37 pm
by A-98
OO! im getting a co2 reg sometime soon, so ill set it up with a 1/4 or 1/2 ball valve and see how it works.

Posted: Mon Mar 12, 2007 12:00 am
by CS
This idea has been 'thought up' many of times. Its generally dismissed at the fact of its gas consumption. I am not sure if it has been done, but that is the general consensus.

Posted: Mon Mar 12, 2007 12:01 am
by MrCrowley
Ball Valves are really simple to modify to make 'em turn 360*
You just cut/file down the small metal/plastic bits sticking up that stop the handle when it turns so far. Plastic ones you may have to open up to modify but thats only the ones with threaed tops.

Posted: Mon Mar 12, 2007 12:37 am
by Matheusilla
I saw a concept that used two ball valves turning full 'round. One ball valve was to open/close air to the barrel and the other had a hole drilled in the side to load in the marbles, one at a time. The two ball valves were connected together with a chain drive and were timed 180 degrees out of phase (I think). The same site also had some other concepts for auto loaders as well. I don't remember the site though, sorry.

Posted: Mon Mar 12, 2007 12:44 am
by A-98
that could be a possibility. it could be rigged like this
..............||
======o{::::::::::::}o......[::::]

key:
{:} is the chamber
= is the barrel
[:::] is a co2 set up
|| is a gravity fed mag
o are ball valves(out of sequence)
....is a pressure hose

i would draw an image, but im too lazy right now. i might do one tomorrow

Posted: Mon Mar 12, 2007 1:05 am
by shud_b_rite
Ok maybe it has been done before but I haven't any seen any before. I will make one as soon as I find a place to buy a ball valve. My local gas/plumbing shop doesn't exist anymore so I will have to find somewhere else.

There is a slight problem that I didn't think of before with this design. How can it be made so that when I take my finger off the trigger the valve will shut off even if there is still air in the chamber? Any ideas?

Posted: Mon Mar 12, 2007 1:28 am
by isban
First of all, A-98, that has got to be the best text diagram I have ever seen.

As for the valve problem could you have a regular valve right before the main valve so that you would be opening and closing both valves at the same time? That way when they are both open it works fine but when closed the first valves keeps the pressure in regardless of the other one's position. Just an idea.

Posted: Mon Mar 12, 2007 1:33 am
by shud_b_rite
isban where do you get your crazy ideas aye? that is such a simple solution i don't know how that idea never crossed my mind. Should work perfectly thanks

Posted: Mon Mar 12, 2007 8:30 am
by Fnord
The problem with ball valves is there is only a relatively short period of time when they close completely, and the rest of the time they are open to a degree.

what you need is something like this:
(note; this might not work, and might not be a new idea, but I though of it myself a minute ago so its new to me)

Posted: Mon Mar 12, 2007 11:34 am
by iknowmy3tables
error
air will only flow when its in the perfect 90 degree position, on a ball valve air will flow when the valve is in almost every position other than 0 degrees
so air is leaking so much it can dump a small chamber untill the projectile has enough space to actully exit the barrel even break certain projectiles

this concept has been used for single shot breechloaders very sucessfully but not like this

Posted: Mon Mar 12, 2007 12:15 pm
by FiveseveN
You could solve the inefficient air dumping problem by using the projectile as the valve:
http://www.spudfiles.com/forums/viewtopic.php?t=1683&
If the projectile fits snug inside the ball, and the ball has the same ID as the barrel, the air behind the projectile can't escape until everything is aligned, allowing the projectile to move forward.
Bullet-shaped projectiles are probably not the best for this application, but you're probably getting the idea.

Alternatively, a mechanical device that rotates the ball swiftly by 90 degree increments could probably be constructed. Or maybe one is better off using a regular ball valve, actuated by a hydraulic/pneumatic ram. With the systems described above, the ram would also control the loading sequence on it's return course.

Posted: Mon Mar 12, 2007 1:48 pm
by pyromanic13
A-98 wrote:OO! im getting a co2 reg sometime soon, so ill set it up with a 1/4 or 1/2 ball valve and see how it works.
wtf!!! you changed your avatar to a worst one!

any way the idea has been thought up many times, it was even suggested for a pneumatic pogostick

Posted: Mon Mar 12, 2007 1:56 pm
by MrCrowley
Jesus Christ your avatar is heavy! Didn't even pick that up 'til then lol :P