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 :: 5 registered, 0 hidden and 68 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Metal barrel sealing tee design

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: MrCrowley » Sat Aug 05, 2006 6:02 am

if i ever make a copper cannon which i will after my first pneumatic due to be finished end of august,i will base the design on this one if you don't mind 8)
  • 0

User avatar
MrCrowley
Moderator
Moderator
 
Posts: 10207
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Country: New Zealand (nz)
Reputation: 4

Unread postAuthor: )DEMON( » Sat Aug 05, 2006 6:05 am

I got all the things to make a new piston housing(and jelly beans). My exhaust valve is a brass one way valve, I could post a pic of it it you like. I got it from a local irrigation store. My new compression fittings are copper, do they also need teflon tape?

*Go ahead, this is a great design.
  • 0

Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: Brian the brain » Sat Aug 05, 2006 10:25 am

Yep. tighten first, unscrew and teflon over the ( now compressed) ring.Make sure to "" merge"the pipe to the ring with the teflon.

If you use a reducer "ring", tape it up too.


This gun should be in the competition!!!
  • 0

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
Brian the brain
Moderator
Moderator
 
Posts: 3494
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Country: Netherlands (nl)
Reputation: 29

Unread postAuthor: )DEMON( » Sun Aug 06, 2006 1:23 pm

You must be crazy, I have not even completed 1/3 of the work I am going to do on this gun.

My piston housing is nice and sealed but the metal fittings always seem to have a leak, I put loads of teflon tape on them! I will just have to apply massive amounts of tape then try again.

I have decided a double barrel will be too hard to make with what I have got but a special barrel which is designed to fire shotgun like cartiges will take its place. I am planning to use a paintball cylinder as a portable fill source. From what I have gathered the set up must go: tank>paintball inline regulator>ball valve>pipe>chamber(back of piston). I am sure this will work but do you know of any ulternitives for the regulator?

I realized today that where I glued the chamber and valve together is a little off center, which causes the barrel to be a little un-paralell to the chamber. I will just buy some new fittings(hehe).

Another question I have been thinking is how to make a barrel sealing/normal piston valve automatic. This would be great for a SMG. If I take the chamber and attatch it to the piston valve directly (so it is perpendicular to the barrel) I could make a cannon to closely resemble the world war 2 STEN SMG. Thats why it would be nice to make an automatic piston.
  • 0

Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: Brian the brain » Sun Aug 06, 2006 6:03 pm

THe reg has no substitute.It's an absolute must.

If you can set the flow of the Co2 tank low enough, so it doesn't interfere(sp?) with the pilot-excaust, it should be semi auto.
May I suggest you unscrew that tiny pressure gauge from you extinguisher, and use that on you gun?
Should make it look even cooler.

The compression fittings have to be tightened very hard.Clamp the fitting into a vice and use a long wrench to get leveridge.
They should seal properly then.

I'm very impressed by this build!
I'm looking forward to seeing more.
  • 0

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
Brian the brain
Moderator
Moderator
 
Posts: 3494
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Country: Netherlands (nl)
Reputation: 29

Unread postAuthor: )DEMON( » Mon Aug 07, 2006 9:16 am

I have completely fixed all the leaks but I can't fire it off at more than 50psi because I can't push the one way valve open. A hammer is the next thing to get. Thanks for the idea of using the small pressure gauge, I will use that.

I have been thinking of a few semi auto ideas but I haven't figured out how to refil after every shot but I have to trigger, bolt and return set up planned. I will keep it simple for now. When I said regulator I ment if there was any other regulators I could use other than the paintball one, I is quite pricey. I know nothing about co2 regulators.

Now with the piston, I am not sure it has to be bigger than the barrel. I just has to have a big surface area. So if you made a piston similar to the one I am using but with and irregular surface that should be enough to open sufficiently. With that you could make small pistols and other goodies.

What do you think I should call it? How about the BULLDOG, project BULLDOG.
  • 0

Attachments
rencarnation.jpg
This pic is a bit hard to see but I made improvements. Small pressure gauge on the front now.
rencarnation.jpg (11.7 KiB) Viewed 866 times
Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: Velocity » Mon Aug 07, 2006 10:40 am

You could call it "Brian the Brain's sawnoff replica". We already have about 5 of those :)

Just kidding... maybe project Bulldog... what do you have left to do?
  • 0

User avatar
Velocity
Brigadier General
Brigadier General
 
Posts: 1039
Joined: Tue Feb 07, 2006 5:42 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: )DEMON( » Mon Aug 07, 2006 11:29 am

Well, I wouldn't want to give away details befor the contest now would I?

I have lots more work to do on this, if you read all the pages then you will find out.
  • 0

Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: Brian the brain » Mon Aug 07, 2006 5:10 pm

I use a soda stream regulator.I like the look of a paintballtank and PB reg better but hey.
And you shouldn't call it a replica.
It has evolved beyond that.It's different( I won't say it's better yet!!).Too bad you can't open the pilot valve that easy.
It will need a REALLY heavy hammer from what I can tell.
  • 0

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
Brian the brain
Moderator
Moderator
 
Posts: 3494
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Country: Netherlands (nl)
Reputation: 29

Unread postAuthor: )DEMON( » Tue Aug 08, 2006 7:39 am

I have some heavy tension springs to use in the hammer design, it will be all steel but I am not sure if it will work or not.
The worst thing that can happen is I have to change the pilot valve.

*Preformance issues.

Ok, I got rid of the one way valve because you needed too much force to open it. It works fine for sprinkler valves but not as main exhaust valves. The only other think I can think of is a ball valve but when I was testing it I found that you need to open it very quickly to get the piston to work.

I came to a conclusion that the more space after your piston, the bigger and faster exhaust valve you need. Therefor I need to get the least space possible behind my piston. I will have to see what happens if I put the ball valve directly after the piston housing but then I will have to put the filling tee and another ball valve after that.

Using a ball valve to fire it off is very loud. I suggest using a spring loaded design for ball valve. Example: with your hammer design, instead of the hammer having a point of rotation on a skrew it can be connected to the ball valve handle (handle removed, connected on the actual threads). Then a trigger like that of yours will lock the 'hammer' when it is cocked. When you pull the trigger the ball valve will be shot open.

What is your opinion?
  • 0

Attachments
ball-valve.jpg
This is my current set up. What I do is open the ball valve and connect a schardar, then fill and close the ball valve and remove the schardar. I need more help.
Last edited by )DEMON( on Tue Aug 08, 2006 9:24 am, edited 1 time in total.
Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: WOW!! » Tue Aug 08, 2006 9:02 am

Sweet gun, that thing is awsome. If you still have problems with the leaks get some liquid sealer(not really a liquid more like a paste), I use it and it seals really good and it costs about the same as 2 rolls of teflon or you could use the gas pipe sealer(yellow tape)that stuff is a bit thicker.
  • 0

(\__/)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination.

My girl friend says I dont listen, at least thats what I think she said...
User avatar
WOW!!
Brigadier General
Brigadier General
 
Posts: 889
Joined: Thu Mar 16, 2006 9:47 pm
Location: New jersey
Reputation: 0

Unread postAuthor: Brian the brain » Tue Aug 08, 2006 11:01 am

If you use a spring you should be able to fill from the chamber side.
I used a ballvalve that has 2 extra 1/4" ports.
That was very expensive.A little spring would solve your problem.

I did the same thing.Screw on the schrader part, fill, close valve, and remove the schrader( in a pipe with endcap)
  • 0

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
Brian the brain
Moderator
Moderator
 
Posts: 3494
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Country: Netherlands (nl)
Reputation: 29

Unread postAuthor: WOW!! » Tue Aug 08, 2006 11:21 am

You could use a femlale quick connect, and then have a male one with the shrader on it and do it that way.
  • 0

(\__/)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination.

My girl friend says I dont listen, at least thats what I think she said...
User avatar
WOW!!
Brigadier General
Brigadier General
 
Posts: 889
Joined: Thu Mar 16, 2006 9:47 pm
Location: New jersey
Reputation: 0

Unread postAuthor: )DEMON( » Tue Aug 08, 2006 11:35 am

I am using a spring so I could try filling from the chamber side. I would like to sort out the valve problem first.I have a question:
If your exhaust valve is too big or your piston is not a perfect seal then could the majority of the air get exhausted befor it exits the barrel?

Another question:
Could the power of the gun be limited if a lot of the air is used to push the piston back?

I want my cannon to be very powerfull but I find if I dont open the valve fast enough the piston dosn't work like it should. Mabey my piston is too short or the housing is too long and the piston is travelling further back than needed.
What should I do? :?
  • 0

Forever dreaming...
User avatar
)DEMON(
Major General
Major General
 
Posts: 1391
Joined: Sun Mar 12, 2006 1:22 pm
Location: Johannesburg South Africa
Reputation: 0

Unread postAuthor: WOW!! » Tue Aug 08, 2006 11:41 am

As long as the piston has a good seal all the way around it should make it go back, if it does not the piston wont move and all the air will go away. That is what happened on mine. The best thing to do is just try it.If it does not work you could put some tape on it a little at a time untill it works, and when it gets a good seal put some heavey grease in the houseing so that it will slide easyer.
  • 0

(\__/)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination.

My girl friend says I dont listen, at least thats what I think she said...
User avatar
WOW!!
Brigadier General
Brigadier General
 
Posts: 889
Joined: Thu Mar 16, 2006 9:47 pm
Location: New jersey
Reputation: 0

PreviousNext

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'