Rapid fire ball valve

A place for general potato gun questions and discussion.
User avatar
shud_b_rite
Specialist 2
Specialist 2
Posts: 290
Joined: Tue Jan 30, 2007 7:10 pm
Location: Auckland, New Zealand

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?
Airbeds... so many different uses
User avatar
homedepotpro
Specialist 4
Specialist 4
Posts: 443
Joined: Sun Nov 26, 2006 1:00 am

that has some potential,
like civil war gatling guns, with a big cranck turning the ball valve
User avatar
A-98
Corporal 5
Corporal 5
Posts: 921
Joined: Thu Apr 27, 2006 7:41 pm
Location: Santa Barbara, CA

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.
There are rules, and then there are hundred dollar bills.
User avatar
CS
Moderator
Moderator
Posts: 1837
Joined: Fri Feb 18, 2005 5:32 pm
Location: Southern Utah

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.
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

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.
Matheusilla
Specialist
Specialist
Posts: 140
Joined: Tue Feb 13, 2007 7:43 pm

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.
User avatar
A-98
Corporal 5
Corporal 5
Posts: 921
Joined: Thu Apr 27, 2006 7:41 pm
Location: Santa Barbara, CA

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
There are rules, and then there are hundred dollar bills.
User avatar
shud_b_rite
Specialist 2
Specialist 2
Posts: 290
Joined: Tue Jan 30, 2007 7:10 pm
Location: Auckland, New Zealand

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?
Airbeds... so many different uses
User avatar
isban
Private 3
Private 3
Posts: 49
Joined: Wed Jan 31, 2007 3:56 pm

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.
User avatar
shud_b_rite
Specialist 2
Specialist 2
Posts: 290
Joined: Tue Jan 30, 2007 7:10 pm
Location: Auckland, New Zealand

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
Airbeds... so many different uses
User avatar
Fnord
First Sergeant 2
First Sergeant 2
Posts: 2239
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Been thanked: 1 time
Contact:

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)
Attachments
there might be some problems with the timing involved in the rotation, such as the projectile not leaving the valve quickly enough and getting stuck, but Im sure with some pressure tweaking it could be made to work.<br /><br />Feel free to try making a gun with my design.
there might be some problems with the timing involved in the rotation, such as the projectile not leaving the valve quickly enough and getting stuck, but Im sure with some pressure tweaking it could be made to work.

Feel free to try making a gun with my design.
dfgsad.GIF (7.8 KiB) Viewed 5349 times
iknowmy3tables
Staff Sergeant
Staff Sergeant
United States of America
Posts: 1596
Joined: Fri Dec 15, 2006 3:57 pm
Location: maryland
Has thanked: 3 times
Been thanked: 9 times

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
User avatar
FiveseveN
Specialist 3
Specialist 3
Posts: 337
Joined: Fri Oct 14, 2005 5:48 am
Location: Nowhere
Contact:

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.
pyromanic13
Corporal 5
Corporal 5
Posts: 913
Joined: Wed Oct 19, 2005 7:54 pm

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
Movie dialogue: "The good die first."
Tom: "But most of us are morally ambiguous, which explains our random dying
patterns."
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Jesus Christ your avatar is heavy! Didn't even pick that up 'til then lol :P
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post