Cad drawing project (PCP airgun)

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
User avatar
Brian the brain
Moderator
Moderator
Netherlands
Posts: 3497
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Been thanked: 7 times

and CO2 turns liquid at between 50 and 60 bar...not 5!!!
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
User avatar
Pete Zaria
Corporal 5
Corporal 5
Posts: 954
Joined: Fri Mar 31, 2006 6:04 pm
Location: Near Seattle, WA

As mentioned already, your twist rate on the barrel's rifling is far too tight - in fact, rifling that tight could cause a dangerous barrel blockage situation. Rifling more like 1 full twist in 10" will provide much better velocity and still yield good accuracy.

My question is, if you're designing a high-pressure, rifled barrel pneumatic, why not use a barrel from a "real" black powder gun, such as a .44 cal muzzle loader barrel? You could probably find one inexpensively on an auction site or gun show, and modify that to use with your pneumatic setup.

The "reducer valve" you mentioned to knock down the pressure of your HPA tanks down to a more reasonable pressure is called a regulator, not a reducer valve, and you're going to need a pretty hefty regulator for this project.

What kind of (main) valve are you going to use? For pressures this high a metal piston valve seems like the obvious choice.

Good luck.

Peace,
Pete Zaria.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 581 times
Been thanked: 347 times

Brian the brain wrote:and CO2 turns liquid at between 50 and 60 bar...not 5!!!
According to wikipedia:
Liquid carbon dioxide forms only at pressures above 5.1 atm
hectmarr wrote:You have to make many weapons, because this field is long and short life
clide
Corporal 3
Corporal 3
Posts: 784
Joined: Sun Mar 06, 2005 3:06 am
Location: Oklahoma, USA
Been thanked: 1 time

Jack, that just means the pressure where it can turn to liquid at all, and that would be at a very low temperature (−56.6°C) for CO2 to be liquid at 5 bar. At room temperature it liquefies at over 50 bar.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 581 times
Been thanked: 347 times

Ah, you meant room temperature :roll: :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

Yay, the valve stress tested at 200 bars.
Well virtually anyway.

*edit* and a cross section render
Attachments
valve_assembly-study 1-results-displacement1.jpg
valve_assembly.jpg
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

Hmm, I've been wondering... What would be the best way to trigger the valve? I was thinking about using a strong magnet and an electro magnet..and a capacitor, But I do not know if this will work.

Does anyone know?

*edit* and a spring to push it back of course
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 581 times
Been thanked: 347 times

Necrosis wrote:I was thinking about using a strong magnet and an electro magnet..and a capacitor, But I do not know if this will work.

Does anyone know?

*edit* and a spring to push it back of course
have a read through here ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

That's indeed where I got this idea from. :D
Not from that particular document, but from the stuff people at my favorite airgun forum have been telling me.
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

Bumpedy bump, Exactly how would I get the air into the chamber? with a schrader valve?

And if so, does anyone have the dimensions to such an apparatus?

*edit* New piston valve assembly thingy! whoo!
Attachments
valve.JPG
valve.JPG (22.88 KiB) Viewed 6645 times
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post