SpudFiles

Ok so, I'm new to this. I'm making a project that shoots a 40mm projectile out of a 9" barrel. I'm thinking of using this 10-32 QEV: https://palmerspursuit.com/products/qev ... 2132702855
I'm using a 16g co2 reg'ed down to ~300psi into a 3" 1/4 nipple. I'm wondering if this would provide enough airflow and pressure to shoot a 40mm projectile at a decent speed? Any tips or input?

10/32 is like 5mm, no where near enough flow your'e gonna need a BIG QEV,
A 1/2" at least https://www.ebay.ca/itm/QE-04-Pneumatic ... 0010.m2109
Or 3/4" https://www.ebay.ca/itm/QE-04-3-4-Pneum ... :rk:3:pf:0

Probably wont need 300psi at that diameter, my Nerf Rival will go 200ft at 150psi, that's 20mm projectiles with little mass to it, it uses a 3/8" solenoid valve, probably the same flow as a 1/4" QEV.
This looks like a 3/4"
[youtube][/youtube]

farcticox1 wrote:10/32 is like 5mm, no where near enough flow your'e gonna need a BIG QEV,
A 1/2" at least https://www.ebay.ca/itm/QE-04-Pneumatic ... 0010.m2109
Or 3/4" https://www.ebay.ca/itm/QE-04-3-4-Pneum ... :rk:3:pf:0

Probably wont need 300psi at that diameter, my Nerf Rival will go 200ft at 150psi, that's 20mm projectiles with little mass to it, it uses a 3/8" solenoid valve, probably the same flow as a 1/4" QEV.

MKIII fin.jpg

This looks like a 3/4"
[youtube][/youtube]

This guy seems to have done a similar thing with some 10-32 pieces and this valve:
https://www.evike.com/products/72398/
https://www.instructables.com/id/Airsof ... ncher-Mod/
I own the taginn shell and can tell you it doesnt hold much air volume, and holds about 300psi
I'm trying to make my own though so I'm not gonna use the taginn, but I'm curious why that works with small threadings and a homemade one wouldnt, thanks.

farcticox1 wrote:10/32 is like 5mm, no where near enough flow

Yes, this sort of QEV is more of a control valve for paintball markers, not really useful as a main valve.

a 40mm projectile at a decent speed? Any tips or input?

What's the projectile (weight, shape) and what speed would you consider decent?

Airsoft ?

jackssmirkingrevenge wrote:

farcticox1 wrote:10/32 is like 5mm, no where near enough flow

Yes, this sort of QEV is more of a control valve for paintball markers, not really useful as a main valve.

a 40mm projectile at a decent speed? Any tips or input?

What's the projectile (weight, shape) and what speed would you consider decent?

Im planning on shooting something like these: http://airsoftpyrotechnics.com/airsoft- ... G4InuhKiUk
I've already picked out my valve though, I went with this one:
I also picked up a slide valve and most of my fittings are 1/4 npt. For the per-shot-tank (idk what its called) im using a 1/2 npt 3" nipple. I'm hoping that'll be enough... will it?

a 40mm projectile at a decent speed? Any tips or input?

What's the projectile (weight, shape) and what speed would you consider decent?

For speeds I was hoping about 150 fps over 50m.

I guess you're trying to make a cheaper version of this expensive toy.

Projectile weight should be about 20 grams, here is a rough simulation in GGDT:



Using the parameters given 600 psi gives you about 110 feet per second. I cut down the barrel to 5 inches because due to the limited chamber volume, anything longer would actually decelerate the projectile.

By using a 1/2" valve we can drop the pressure to 500 psi and get the performance you would like:





I highly suggest using GGDT to model your launcher before purchasing parts and planning dimensions.

That guy did do a good job with his though, damn it, I want to build one now.

farcticox1 wrote:That guy did do a good job with his though, damn it, I want to build one now.

download.jpg

We are two who want to do one of these! :bounce:

hectmarr wrote:We are two who want to do one of these! :bounce:

Three!

It's been done in airsoft:

[youtube][/youtube]

Now imagine that with some "proper" pneumatic cartridges at a couple of thousands of psi...

As the ammunition is large, you could put the compressed air on themselves. Beautiful weapon to hit annoying sellers :bom: jajajaja !!

hectmarr wrote:As the ammunition is large, you could put the compressed air on themselves.

This is how the launcher in video works, it uses airsoft 40mm grenades that use the same ball-lock system that I have been experimenting with:

Its operation is very clear. It's quite simple, in general.