Help with First Pneumatic Cannon

[LordFarquaad]

Hey all!

Relatively new to pneumatics - I've searched past threads endlessly but still haven't found what I exactly want. I'm sorry if any of this is actually obvious. I'm currently starting my first mini semi auto project, the main focus of this project is for it to be compact therefore using CO2 cartridges (such as the ones used for pumping up bicycles), as well as a QEV from Ebay and a flow control manual slide valve. I understand the pilot valve is where the slide valve should be attached and somehow the CO2 cartridge should be attached to the slide valve? Do I need a regulator? The "A" port from what I've learnt is where a chamber is attached? Where can I find a small chamber? Or do I have to make one my self? The "R" port is where the barrel is attached?

New to the forum and to pneumatics, so don't judge too harshly

Thank you all!

[Air2theBrain]

Hi LF...i'm afraid you haven't quite searched enough, for the answers to your QEV questions are readily available in numerous threads here.

You really need to search more in regards to chambers..etc.

Im new to the forum and pneumatics also..check my posts i've asked some very dumb questions, but the answers to yours are easily found.

Dont take anything harshly, take it as constructive criticism.

Have you done an intro thread yet....? You only have 1 post to your name so i guess not..how about you introduce yourself to everyone..describe what you want to build, etc.

QEV's are easy to set up and get going, i built my first pneumatic in around a week with full semi-auto.

Only thing you need to wrap your head around is the ammo feed through a magazine...i had to figure that myself, i found no inspiration for that here or anywhere else.

You get that part sorted then fun times ahead.

[LordFarquaad]

Hey mate!

Thanks for the constructive criticism much appreciated.

I don't understand with regards to the chamber, any pointers on that would be also much appreciated.

I've got a 3D Printer and have designed many things from various contraptions to drones, so no problem with the ammo, magazine etc.

Thanks!

[farcticox1]

Don't know if a co2 cartridge will give you many shots, I think someone asked the question a little while ago.

http://www.spudfiles.com/pneumatic-cann ... 26463.html

Here's something else

http://www.spudfiles.com/spud-cannon-re ... 26613.html

Chambers are mostly made by the builder, threaded steel pipe fittings are easy to work with and will take decent pressures, I have been using PVC lately for chambers but it is more fragile and only for use with low pressure, I take mine up to 140psi max.

To make a semiauto mechanism, there's many many ways to do it.

[jackssmirkingrevenge]

I doubt you'll get many shots from a 12 gram cartridge. A QEV dumps a lot more air than the hammer valves they're typically used with, so your chamber is going to have to be tiny, and also because of the exhaust system a lot of the gas is going to be wasted through the slide valve as you pilot.

[farcticox1]

Heres a semi auto idea

https://www.youtube.com/watch?v=t6ja7UMEkyo

[Air2theBrain]

Heres a semi auto idea

https://www.youtube.com/watch?v=t6ja7UMEkyo

I still can't wrap my head around hammer valves...i don't know why but they confuse me greatly.

[LordFarquaad]

Thank you all for your input.

I'm just trying to design something small using only a CO2 cartridge, if QEV is not an option what would you all recommend.I tried a simple search of "Hammer Valve" but nothing identifiable came up. As I'm just entering the world of pneumatics and I don't really fancy building my own valve at this point in time. So any directions would be great!

Thank you!

[jackssmirkingrevenge]

This project might be of interest: http://www.spudfiles.com/airsoft-pellet ... ml#p276030

[LordFarquaad]

This project might be of interest: http://www.spudfiles.com/airsoft-pellet ... ml#p276030

Thanks Jack, problem is I want to fit the pneumatics to my 3D printed rifle which incorporates my own design of trigger, magazine etc so the valve in-built trigger is a bit of a problem for me.

Thank you!

[jackssmirkingrevenge]

A drawing of what you're hoping to achieve will help us help you

[LordFarquaad]

A drawing of what you're hoping to achieve will help us help you

Unfortunately I can't draw to save my life.

But let me rephrase want I have in mind. I want to make the most compact pneumatic cannon using a CO2 cartridge, with the QEV not being an option, what other options do I have?

[jackssmirkingrevenge]

what other options do I have?

This is contingent on the answers to the following questions:

- what's your budget?
- what technical skills do you have?
- what tools do you have access to?
- what materials do you have access to?

[LordFarquaad]

what other options do I have?

This is contingent on the answers to the following questions:

- what's your budget?
- what technical skills do you have?
- what tools do you have access to?
- what materials do you have access to?

1. My budget is fairly decent I suppose, willing to spend around $50-$100 AUD all together.
2. Technical skills include CAD and 3D printing, repair work, decent with electronics and soldering.
3. All Powertools, 3D Printers, all different types of Welding Machines (not at this right moment).
4. Standard materials from hardware shop, due to family business can access special materials if really required.

[farcticox1]

That's probably more resources than Iv'e got