SpudFiles

if the projectile is tight fit I don't think you can feed it by gravity,

and again its easy to modify ball valves to rotate in 360 degrees, man FiveseveN you really got guns on your mind, you probebly got the idea of a ram from the G11's gas operation system

and now there is another propblem now the chamber is empty so it has to be conected, even then the chammber dosen't have much time to refill with the angle that the ball valve is open
only if we could machine ball valves stuff like this would be easier

Nice idea..but a bit impractical due to high gas consumption ans slow valve opening.Not very powerful.
Now imagine a "regular"piston gun.Exhausted through a 3 way ballvalve that has a larger reservoir filling from the third ballvalve inlet, and crank away!!!
Use a paddle-mag or a piston driven bolt to load the ammo..


Fitting a CO2 bottle and regulator instead of a large reservoir would make it a very nice gun indeed...

Brian are you thinking about using a 3way ball valve to divert presure? cause you should know that 3ways can't divert presure because the ports are too big, I thought of that one untill I realized that the ports in ball valves are so big that at half way all openings are conected/flowing. I'll get a pic to show you and others cause I'm afraid many people mistook 3way ball valves as a a way to divert presure in spud guns and such

pyromanic13 wrote:wtf!!! you changed your avatar to a worst one!

MrCrowley wrote:Jesus Christ your avatar is heavy! Didn't even pick that up 'til then lol

i know, i hate PC's. but i did feel alittle guilty changing it, i think ill alternate every week or so....frog kitten

try again after seeing this...http://en.wikipedia.org/wiki/Ball_valve

pyromanic13 wrote:wtf!!! you changed your avatar to a worst one!

if you look really hard you can see a scwastica on it.

i have though of that idea toobut i think you might not get as many shots out of it as you want

Yea, I reckon using a 2kg fire extinguisher at 120psi will only give ma about 5 or 6 shots. I could make the motor spin faster to give me more shots but that they wont be as powerful.

I wasn't planning on using another ball valve as a gravity loader but that is a good idea too, but a little too complicated for me.

Another Idea I had was to use a small pneumatic drill (wrench, ratchet whatever) hooked up to a secondary tank that will turn the ball valve. This will mean that I can activate the whole thing just by turning a ball valve without an electronic switch. Anyone know how much air an air drill sucks up to turn slowly?


Even if this doesnt work as well as I wanted it will still make a cool sound and I could always hook it to an air compressor.

Been done before.I actually built one and my BBMG worked horrible.

Follow the link to see the excuse of a BBMG.


http://www.spudfiles.com/forums/viewtop ... 699&#43699

When working on the robot for the FIRST competition, we had these really nifty three-way pneumatic solenoids which took an input and either directed it into tube A while venting B, or vice versa. I wish I could remember the manufacturer because I've thought about using it myself in an autocannon. What you could do is alternate fire so that while one fires, the pressure is cut from the other allowing a projectile to fall from the magazine. It is also a lot faster and more efficient than a sprinkler valve.

I wish I could remember more about it, try looking at pneumatics supply websites, its used for pneumatic cylinders to actuate them in and out, so it must be fairly common. Our robot had a very small tank and it took a lot of juice to run the compressor, so I know it must have been fairly efficient.

I 've been working on something similar although a lot more basic for a while.

I am starting with a 3/4in Apollo 3w ball valve housing with 2way ball valve guts
Everything else is pretty much changeable

control will be a sear/hook and spring to open the valve
and a gas piston from a t fitting off the barrel to reset the valve ,


I am aiming for 400/650 cycles per minute, not so much to conserve air as ammo and to be somewhat more realistic .

The pic is a far from finished ,rough idea

SPG and myself had been throwing this idea around a while ago on spudtech.

In it's simplest incarnation, the following setup with one ballvalve and the BBs already inside the chamber will give a very efficient BBMG with no dead space, though it's more of a "hosepipe" than a "machine gun" really.



If you add a motor to continuously turn the ball valve you'd practically end up with a "machine gun", although there are some issues such as having a motor geared with sufficiently large torque to rotate the valve effectively, as well as wiring it in such a manner to ensure that when you remove the current, it's in the "closed" position, like windshield wiper motor circuits...

I might have to build something similar. What I would do is Use duel ball valves (at least the same size of the barrel for optimum flow) on a single gear motor mounted so when one is open the other is off, I would want at least a 5"x(the dia of the barrel) chamber for expansion, 150-200lbs of pressure (supplying that pressure a regulated 20 or 50lb Co2 tank (rent about $5 a month + fills). A gravity fed hopper or chute with a stopper (like a ball stopper on a paintball gun) in the barrel. That in my mind would work rather well depending on the speed of the drive motor.

http://www.spudfiles.com/forums/files/start_212.jpg

holy ghetto batman!

_Fnord wrote: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)

i see complete and total potential of jamming, no offence. good idea with ball valve but big ball valves are hard to turn and that wouldn't realy be automatic, it would be a complete pain with a low fire rate.

not dissin the idea, i just think it could of been a little more complex. good start, lets make it a pain to build now >.<

jackssmirkingrevenge wrote:SPG and myself had been throwing this idea around a while ago on spudtech.

In it's simplest incarnation, the following setup with one ballvalve and the BBs already inside the chamber will give a very efficient BBMG with no dead space, though it's more of a "hosepipe" than a "machine gun" really.

already been made, ALOT.

zeigs spud wrote:already been made, ALOT.

By who?