Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 73 users online :: 4 registered, 0 hidden and 69 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Big Stuff

Built a pneumatic cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
Sponsored 
  • Author
    Message

Big Stuff

Unread postAuthor: Vice » Fri Jun 30, 2006 6:08 pm

This is my Pneumatic cannon, I call it Big Stuff... until I can think of a better name.
Image
It's built completly out of Sch 40 PVC, save for the Sch 20 barrel (wrapped in duct tape) that I use to launch tennis balls and cans of spray paint. Both barrels are a 2.5 inch outside diameter, but the tank is a 3 inch outside diameter.
Image
I didn't expect it to as a powerful as it really is, but it's got some pretty serious kick behind it. My theories are that I used a large steel ball valve, and a long barrel to allow more time for the projectile to accelerate with the expanding air behind it. I also think that it was because the tank was built large enough to supply air for the projectile's entire trip through the barrel (to not experience a vacuum effect towards the end), so it can really send something flying. Shot at 90 degrees relative to the ground it can, with about 80 or so PSI in the tank, launch a tennis ball into the air for around ten seconds, which is ROUGHLY (without figuring in air resistance.. a rather large factor..) 125 meters. The cannon design was loosely based off of the design of "Pnewton's Petard" from the book "Backyard Ballistics" (An AWESOME book if you like this kind of stuff)
Any Questions or comments?
-Vice
  • 0

User avatar
Vice
Private
Private
 
Posts: 7
Joined: Mon Jun 26, 2006 1:20 pm
Reputation: 0

Unread postAuthor: SpudStuff » Fri Jun 30, 2006 6:12 pm

get a sprinkler valve and modify it via the how to
  • 0

User avatar
SpudStuff
Major General
Major General
 
Posts: 1410
Joined: Sat Dec 10, 2005 3:55 pm
Location: Cupertino, California
Reputation: 1

Unread postAuthor: mark.f » Fri Jun 30, 2006 7:31 pm

That duct tape won't save you. Get a pressure rated 2.5" SCH-40 barrel if you want to shoot tennis balls... especially on a pneumatic.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: PVC Arsenal 17 » Fri Jun 30, 2006 8:21 pm

Just curious... I have a book called Backyard Ballistics that has a plan in it for a cannon very similar to this. Is that where you got the idea?

*EDIT* Sorry didn't see you did mention that in your post. Cool. I like that book a lot.
  • 0


PVC Arsenal 17
Major General
Major General
 
Posts: 1762
Joined: Mon Mar 27, 2006 4:18 pm
Location: United States
Reputation: 1

Unread postAuthor: Torch » Fri Jun 30, 2006 8:30 pm

Cool cannon! Have you thought of puting a stand on it? Might help with the kick :)
  • 0

User avatar
Torch
Sergeant Major
Sergeant Major
 
Posts: 180
Joined: Tue Jun 27, 2006 2:08 pm
Location: Maryland
Reputation: 0

Unread postAuthor: x.X.Cpt.Rollhart.X.x » Fri Jun 30, 2006 9:23 pm

The "T" design suck really hard ....

why didnt you make a simple over and under cannon ?

and a sprinkler valve is definetly better than your lil ball valve.
  • 0

User avatar
x.X.Cpt.Rollhart.X.x
Staff Sergeant
Staff Sergeant
 
Posts: 128
Joined: Sun Apr 30, 2006 6:46 pm
Reputation: 0

Unread postAuthor: Shrimphead » Fri Jun 30, 2006 9:26 pm

Mark, barrels don't need to be pressure rated. As long as they are decently strong then it's fine. But if a chamber were to rupture, duct tape wouldn't do anything.
  • 0

Controlled insanity = Genius
Life flies when you're being dumb.
User avatar
Shrimphead
Colonel
Colonel
 
Posts: 509
Joined: Thu Nov 17, 2005 7:42 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: benstern » Fri Jun 30, 2006 9:34 pm

barrels need to be pressure rated.
let's see you put pvc barrel on a gun.
  • 0

User avatar
benstern
Donating Member
Donating Member
 
Posts: 909
Joined: Wed Sep 21, 2005 8:24 pm
Reputation: 0

Unread postAuthor: CS » Fri Jun 30, 2006 9:46 pm

Benstern, not so much. Barrels are exposed to such pressure over a MUCH shorter time. Since when the projectile moves the volume increases, via dropping the air pressure. So you decide if exposing a barrel to several milliseconds of pressure is suitable.
  • 0

User avatar
CS
Donating Moderator
Donating Moderator
 
Posts: 1897
Joined: Fri Feb 18, 2005 5:32 pm
Location: Southern Utah
Country: United States (us)
Reputation: 4

Unread postAuthor: Vice » Sat Jul 01, 2006 12:45 am

The Sch 20 barrel works wonders for me, it does really well with tennis balls especially because they slide in very smoothly and don't require a high pressure build up behind them for them to glide out of the barrel, as opposed to being stuck to where it would take much more pressure to launch. I think the Sch 20 is ideal for tennis balls and for things that are not very heavy. Even a can full of soda will launch easily out of it with no problems... the ball valve I think also reduces the risk of it exploding due to the slightly longer amount of time it takes for it to release the air, so maybe I'll save the sprinkler valve for a later project when I use some heavier things. :)

The "T" design suck really hard ....

why didnt you make a simple over and under cannon ?

and a sprinkler valve is definetly better than your lil ball valve.



P.S. Actually, I like the "T" design because it's easier to aim then an "Over-under cannon", and it works really well for me because the less parts you have in a cannon, the fewer chances you have of something breaking. Where would we be without different designs? How would we improve them? By the way, ball valves are cheaper and can withstand a considerable amount of PSI. A longer barrel would be a simple way to make up for a slower release of air, especially with a Sch 20 and it's lack of friction on a tennis ball (for example).
Cheers!
-Vice
  • 0

User avatar
Vice
Private
Private
 
Posts: 7
Joined: Mon Jun 26, 2006 1:20 pm
Reputation: 0

Unread postAuthor: Vice » Sat Jul 01, 2006 12:54 am

Cool cannon! Have you thought of puting a stand on it? Might help with the kick :)


Thanks! I did think of putting a stand on it of some sort but tossed the idea because I didn't have too many issues with aiming it and nothing really with the kick.. it's pretty cool the feel the power of that thing sometimes :)
-Vice
  • 0

User avatar
Vice
Private
Private
 
Posts: 7
Joined: Mon Jun 26, 2006 1:20 pm
Reputation: 0

Unread postAuthor: SpudStuff » Sat Jul 01, 2006 1:03 am

are you sure that isn't a SDR-21 barrel. as i have seen 2.5" in that class
  • 0

User avatar
SpudStuff
Major General
Major General
 
Posts: 1410
Joined: Sat Dec 10, 2005 3:55 pm
Location: Cupertino, California
Reputation: 1

Unread postAuthor: Vice » Sat Jul 01, 2006 1:12 am

Well to be honest I don't know, but I'm pretty sure it's just regular Sch 20 PVC.. that's what I bought it as.. and the duct tape is covering up the markings.. so I can't really go back and check :\
  • 0

User avatar
Vice
Private
Private
 
Posts: 7
Joined: Mon Jun 26, 2006 1:20 pm
Reputation: 0

Unread postAuthor: SpudStuff » Sat Jul 01, 2006 1:25 am

PVC dosn't come in sch 20 it comes in 10, 40, 80, 120, 160 or SDR- 13.5, 21,26,60
  • 0

User avatar
SpudStuff
Major General
Major General
 
Posts: 1410
Joined: Sat Dec 10, 2005 3:55 pm
Location: Cupertino, California
Reputation: 1

Unread postAuthor: Rambo » Sat Jul 01, 2006 10:45 am

Oh man can't you buy a bigger ball valve?Or you paln to launch heavy steel balls?
  • 0

User avatar
Rambo
Colonel
Colonel
 
Posts: 509
Joined: Sun Jan 15, 2006 2:07 pm
Reputation: 0

Next

Return to Pneumatic Cannon Database

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Yahoo [Bot]

Reputation System ©'