semi automatic pneumatic airsoft design

[burgerace69]

here is my idea that i have finally put into a gif animation. The goal is to have a portable gun that will give you multiple shots without reloading.
http://img23.imageshack.us/img23/3016/sg172.gif

[POLAND_SPUD]

Have you considered adding an extra piston or two and some dead space here and there ?

one word -> Rube Goldberg machine (yeah I know... 3 words not 1)


There are a lot simpler designs, you know ?

[jackssmirkingrevenge]

Wow, and I take POLAND_SPUD to task for his designs which I perceive to be overcomplicated

What's the advantage of this over a simple QEV-popoff-blowback breech setup?

edit: jeebus, even he thinks it's overcomplicated

[Fnord]

Instead of all those manual air controlled parts why don't you set up build a circuit to control stuff electronically with solenoid valves?

something like this

I am so helpful. were's ragnarok?

[saefroch]

The design seems like it would work, even if it is way over-engineered. My only objection to the design is that you'd need to have a regged-down tank feeding into the system, or I'm pretty sure that bottom valve won't close.

[burgerace69]

The design seems like it would work, even if it is way over-engineered. My only objection to the design is that you'd need to have a regged-down tank feeding into the system, or I'm pretty sure that bottom valve won't close.

well i have a lead going from the reservoir to the air chamber to equalize pressures so that the spring on the lowest valve can over power the res chamber. The bottom should close as long as the area infront and behind the piston are = .

and dang...never knew what a QEV was till now, but i would think that the QEV would take a bit of time to refill so that the piston isnt blown back. It would be tough to think of a valve to allow faster air flow for refilling this.

And what it like about the piston valves to sprinklers is that there is way more power. Ive always wanted to do a piston exhaust because i wanted the fasted release possible for that main piston lol

[burgerace69]

i dont know if anyone has sucessfully tried this or not, but if the ammo reloading system was simply the piston with a pin that extended into the barrel, replacing the piston with holes in it, do you guys think that it would stay opened long enough for the ammo to drop in?

[velocity3x]

do you guys think that it would stay opened long enough for the ammo to drop in?

I don't see how you can control it to fire a single projectile. As the pin retracts during firing, I see a possibility of a few balls loading before the pin closes. When the pin closes, I think it will mildly shove a waiting ball (assuming one will be waiting) out of the barrel and the barrel will be empty for the next shot.

[burgerace69]

do you guys think that it would stay opened long enough for the ammo to drop in?

I don't see how you can control it to fire a single projectile. As the pin retracts during firing, I see a possibility of a few balls loading before the pin closes. When the pin closes, I think it will mildly shove a waiting ball (assuming one will be waiting) out of the barrel and the barrel will be empty for the next shot.

that was what i was thinking. Of course i would use a rubber stopper, which i do have, but i dont think that would be effective enough to load it precisely. if you have any suggestions on the ammunition loader i would appreciate it.

[POLAND_SPUD]

they say this is complicated->
http://www.spudfiles.com/forums/semiaut ... 20259.html

here is another one based on the same principle->
http://www.spudfiles.com/forums/semi-au ... 21799.html

[burgerace69]

i like that idea- it just seems like air leaking might be a problem unless there was a rubber stopper or something to press up against the barrel and the piston behind it. (it would need to be a backwards piston)

[POLAND_SPUD]

No offence but....
If you didn't get it... we are saying that the design is a little bit overcomplicated

Even if you get it to work it won't be very powerful due to deadspace, excessive pilot volume and things like that

Have you checked the links I posted ??

[velocity3x]

i also intent to have one way flow valves in the two main pistons for faster air refilling.

If fast filling is your objective, you can achieve continuous filling without all of the mechanical apparatus shown in your drawing. I've looked at your drawing and I'm afraid I'll have a Brain Aneurysm long before I begin to understand it.

IMO, you should design/build your gun as two SIMPLE systems.....A valve / barrel mechanism that fires on command and a controllable loading mechanism. Then merge the two mechanisms together.

[burgerace69]

i want to clarify this: I want to make a fully semi automatic gun that can be carried. this means that whether i use a QEV or a piston valve i need to have some way of preventing a complete discharge of the air reservoir. The bottom valve on this diagram is therefore necessary or the pilot valve will drain it.Again, if i use a QEV this might not be as much of a problem, but it will still drain the tank unregulated. It all depends on the spring's ability to close, which is not reliable.

Second thing, I'm using a piston valve as the pilot for the primary. If anyone has used a modded sprinkler valve for a pilot they would know that it will cause the primary piston to move significantly faster than an unmodded one...This means that if a piston is used as a pilot then the speed of the primary will be faster than a modded sprinkler valve. This is why it looks complicated to you, but it really isnt any more complicated than a piston valve gun with modded sprink pilot valve and a backflow valve on the air tank. (which i am making before i make this one)

I did see the links that POLAND_SPUD posted. it is a reversed form of what i made for the ammo reload, however it does look slightly more reliable.

[jackssmirkingrevenge]

IMO, you should design/build your gun as two SIMPLE systems.....A valve / barrel mechanism that fires on command and a controllable loading mechanism. Then merge the two mechanisms together.

Oooh oooh!

i want to clarify this: I want to make a fully semi automatic gun that can be carried.

There are far simpler ways to achieve that. Don't let us stop you from building your design though, it's just that it seems a little weird to want to eat soup with chop sticks when there's spoons around