Some questions about a design.

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warhead052
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Fri Aug 31, 2012 12:50 pm

Ok, I've been put in charge of making a paintball heavy machine gun for my airsoft team, and I need some help with this design. Basically, I need the semi auto that poland perfected, but in full auto. Doesn't have to be fast, just needs to work. This is what I have so far.

Image

If it doesn't make sense, here's the parts that correspond with the numbers in the picture.

1. Air Control Valve Spring Return, 4-Way, 1/8" NPT Pipe, Straight Lever
2.Push to connect 1/4" Tube OD X 1/4" NPT Male Pipe
3.Quick-Exhaust Air Valve 1/2" Inlet, 1/2" Cylinder/Outlet, 3/4" Exhaust
4.3/4 Male X 1/4 Fem Pipe Size, Hex Reducing Bushing
5. 1/4 Pipe Size, Fem X Male X Fem Tee
6.Multirange Brass Pop-Safety Valve 1/4 NPT Male, 25-200 PSI
7.Push to connect 1/4" Tube OD X 1/8" NPT
8.High-Pressure/Vacuum Polyethylene Tubing
9.1/8 Pipe Size X 1-1/2" Length, Long Hex Nipple
10. 1/4 X 1/8 Female Pipe Size, Reducing Coupling
11.Industrial 1/4 hose quick disconnect
12. 1/2 Pipe Size X 1-1/2" Length pipe nipple.
13.Stainless Steel Air Cylinder Nose-Mount, Spring Return, 3/4" Bore, 1" Stroke
14. 1/2 X 1/4 Female Pipe Size, Reducing Coupling
15.Push to connect 1/4" Tube OD X 1/8" NPT Male Pipe

That's it for now. I will buy stuff for the barrel in person, but this is what I am ordering. I need input, so let me know if it would work. I would add a flow regulator if needed to slow the flow so that it has time to cycle properly, but I don't know if its needed. Thanks for any input.
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POLAND_SPUD
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Fri Aug 31, 2012 1:21 pm

I admit I am drunk at the moment but I don't think that's the reason why I don't understand how you turned that into a fullautogun?

EDIT
ohh now I see... that will require some tweaking you know?

you got to make sure that the air cylinder has enough time to retract fully and enough for ammo to fall down from the mag/hopper... As soon as the pop off resets air will enter the chamber and extend the cylinder again - so you might get it to work but that's not 100% sure
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warhead052
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Fri Aug 31, 2012 1:35 pm

Yeah, I am going to order a pop off that is adjustable so I can fine tune the time needed to fill then fire. If I time pressure and the pop off just right, will that make it more likely to work?
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POLAND_SPUD
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Fri Aug 31, 2012 2:02 pm

well there is just one way to check that :-D
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wyz2285
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Fri Aug 31, 2012 2:03 pm

I had this idea of using the cylinder in pop off full autos, what really matters it's not the pop off but the flow from chamber to cylinder. What you need it's what I call one way flow control valve, witch means it only controls the flow from one direction to another but not both sense. In you case you need the cylinder to be emptied fast but lower recharge speed so there is enough time to do the reloading. You can do that by modify a normal one way valve (let it leak a little) to control the flow. I did the same with my semi.
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warhead052
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Fri Aug 31, 2012 2:08 pm

wyz, just as well I have a few one way valves to spare. I will give that a shot.

Poland, I agree, one way to find out!

Over all though, this design should work for semi auto at least, right? If it works semi auto, I will just tell the captain of the team to learn to move his fingers faster.
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