4inch coax predictions?

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 10:47 am

hey guys, pyro and I are going to build a 4 inch coaxial with a 2inch barrel later on today. what kind of performance do you think we are going to be getting? with a cauk tube.
thanks i cant use ggt or whatever its called.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26183
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 547 times
Been thanked: 326 times

Donating Members

Fri Jun 08, 2007 10:57 am

if you can give us the full dimensions, pressure you intend to use and weight of the caulk tube i'm sure we can give you an idea.

Why can't you use GGDT? You should try, it's a real gem of a program and saves you a lot of trial and error playing with variables before you start building.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 11:03 am

ok, 4 feet of 4inch for the chamber, 6 ft of 2inch for the barrel, 100 psi, and i dont know the weight of the tube as i dont have any at the moment.
i cant use ggdt because i have a mac without exel
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26183
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 547 times
Been thanked: 326 times

Donating Members

Fri Jun 08, 2007 11:17 am

here's a rough estimate with a 100 gram projectile
Attachments
Animation2.gif
Animation2.gif (21.62 KiB) Viewed 2801 times
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 11:18 am

thanks, thats just what i needed
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26183
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 547 times
Been thanked: 326 times

Donating Members

Fri Jun 08, 2007 11:36 am

Interesting to note that that predicted muzzle energy is roughly twice that of a 9mm pistol round :shock:
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 11:38 am

sounds interesting. we should have some fun with this one
User avatar
rna_duelers
Staff Sergeant 3
Staff Sergeant 3
Posts: 1739
Joined: Mon Sep 26, 2005 7:07 am
Location: G-land Australia

Fri Jun 08, 2007 9:24 pm

Twice the muzzle energy as a 9mm pistol round...wow...

What are you going to make the piston out of?Try and make it light as possible.The love for big coaxial never ends,how much is this project costing?
Image
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 9:28 pm

were going to try and keep it under 100$. 3inch endcap for the piston.

unfortunately, we didnt get to start the build tonight. no gass money
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26183
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 547 times
Been thanked: 326 times

Donating Members

Fri Jun 08, 2007 10:10 pm

rna_duelers wrote:Twice the muzzle energy as a 9mm pistol round...wow...
It gets better, with a 2 inch steel ball as ammunition, the energy is about 100 ft/lbs greater than a 0.44 magnum round :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 10:14 pm

jackssmirkingrevenge wrote:
rna_duelers wrote:Twice the muzzle energy as a 9mm pistol round...wow...
It gets better, with a 2 inch steel ball as ammunition, the energy is about 100 ft/lbs greater than a 0.44 magnum round :D
HOLY WOW! i think this one might have to live down at pyros farm....
User avatar
turbohacker
Specialist 3
Specialist 3
Posts: 392
Joined: Wed Dec 20, 2006 12:34 am

Fri Jun 08, 2007 11:07 pm

It works great!!!
I reccomend using a slightly filed 3"cap as your piston as seen on my gun.
Attachments
P1010013.JPG
P1010001.JPG
<-- This is not a cat avatar

If it walks like a dog, sratches like a dog, and barks like a dog, than its probobly a...-TURTLE, it's a TURTLE!!! Cant you see?!!!
frankrede wrote:Great googlay mooglay!
Thats a beast!
User avatar
mopherman
Corporal 3
Corporal 3
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Been thanked: 1 time

Fri Jun 08, 2007 11:13 pm

turbo, i just checked out your coaxial. I love the flanges ( or whatever they are called) how long did the sanded cap take? I only have a drill and a dremmle
edit: to avoid confusion, I meant pyromaniac not pyro. too many pyro names....
edit edit: sorry didnt see your pics. thought you meant the green gun
User avatar
turbohacker
Specialist 3
Specialist 3
Posts: 392
Joined: Wed Dec 20, 2006 12:34 am

Fri Jun 08, 2007 11:21 pm

Yeah, i just drilled the hole for the bolt dead center and mounted it in my drill press. I then ground and fit a few times with an angle grinder with a flapper wheel. A drill mounted in a vise would probobly work just as well...
<-- This is not a cat avatar

If it walks like a dog, sratches like a dog, and barks like a dog, than its probobly a...-TURTLE, it's a TURTLE!!! Cant you see?!!!
frankrede wrote:Great googlay mooglay!
Thats a beast!
User avatar
rna_duelers
Staff Sergeant 3
Staff Sergeant 3
Posts: 1739
Joined: Mon Sep 26, 2005 7:07 am
Location: G-land Australia

Fri Jun 08, 2007 11:22 pm

Ahh yes an 3"endcap,fill it with space filling foam or similar to reduce the pilot volume.Haha I wouldn't shoot something like that in town or a city thats a little crazy and could see something bad happening..

@jackssmirk-A .44 magnum,thats getting out of hand!You gave me links to a website with caluclators to find the muzzle energy of projectile and I can't seem to find them.If you could be as good to post the link that would great.Wanting to find the energy of some of my pneumatics :wink: .
Image
Post Reply