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 56 users online :: 7 registered, 0 hidden and 49 guests


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

Registered users: Baldyforks, Bing [Bot], Exabot [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

will this work?? piston valve

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

will this work?? piston valve

Unread postAuthor: The_Kangsta » Tue Jul 29, 2008 5:35 pm

Will this idea work? its not really a *proper* barrel sealing valve, but it should work.
  • 0

Attachments
piston valve.jpg
piston valve.jpg (9.41 KiB) Viewed 360 times
Live now, die later
User avatar
The_Kangsta
Corporal
Corporal
 
Posts: 69
Joined: Sat Oct 27, 2007 9:20 pm
Location: Canada
Reputation: 0

Unread postAuthor: Coodude26 » Tue Jul 29, 2008 5:45 pm

Whats with the arrows at the end of the chamber?
And no one can tell you for sure if something will work or not because you haven't even built it yet.
  • 0

User avatar
Coodude26
Master Sergeant
Master Sergeant
 
Posts: 167
Joined: Sun Apr 20, 2008 1:03 pm
Reputation: 0

Unread postAuthor: jrrdw » Tue Jul 29, 2008 5:48 pm

It might. I'de move the sealing face to the center of the tee. More flow that way.
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6540
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: Gippeto » Tue Jul 29, 2008 7:19 pm

If it was a straight pipe, it would be a co-ax. Which is just fine! :D


Comments;

If that is anywhere near scale, you should reduce the pilot volume.

Otherwise, jrrdw gives good advice, as always.
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2394
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: potatoflinger » Tue Jul 29, 2008 7:22 pm

It will work, it is pretty much just a coaxial piston valve with a tee and another air chamber coming out of it.
  • 0

It's hard to soar with eagles when you're working with turkeys.
User avatar
potatoflinger
Brigadier General
Brigadier General
 
Posts: 1136
Joined: Thu Nov 02, 2006 3:26 pm
Location: Maryland
Reputation: 1

Unread postAuthor: mobile chernobyl » Tue Jul 29, 2008 7:32 pm

What size Tee is that you plan on using? If its a 2" I have a way better design thats just as easy to make that I use on my "1 gallon" launcher.
  • 0

User avatar
mobile chernobyl
Colonel
Colonel
 
Posts: 732
Joined: Sun Dec 03, 2006 11:53 am
Reputation: 9

Unread postAuthor: Mr.Sandman » Tue Jul 29, 2008 7:39 pm

pretty good but why this design? also what do you plan on using as your piston? wait nevermind i was looking at it wrong.
  • 0

User avatar
Mr.Sandman
Donating Member
Donating Member
 
Posts: 762
Joined: Fri Mar 28, 2008 9:10 am
Country: Antarctica (aq)
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: the unit » Tue Jul 29, 2008 10:32 pm

Gippeto wrote:If it was a straight pipe, it would be a co-ax. Which is just fine! :D


Comments;

If that is anywhere near scale, you should reduce the pilot volume.

Otherwise, jrrdw gives good advice, as always.


while your talking about pilot volume, what would be a good pilot volume for a 1.5" chamber co-ax :D
  • 0


the unit
Specialist
Specialist
 
Posts: 51
Joined: Tue Jun 24, 2008 8:20 pm
Reputation: 0

Unread postAuthor: MrCrowley » Tue Jul 29, 2008 11:16 pm

Coodude26 wrote:Whats with the arrows at the end of the chamber?
And no one can tell you for sure if something will work or not because you haven't even built it yet.

The arrows show that the chamber is not to scale and will be longer i'm guessing.

He is wondering if the concept will work, if you understand physics you can tell if something will work before building it...idiot. :roll:
  • 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: Gippeto » Tue Jul 29, 2008 11:27 pm

You didn't say what your barrel id was so I'll just give an example.

If your barrel id is other than .750" you can adjust things accordingly.

Just remember that TOTAL PISTON TRAVEL should (ideally) be equal to id/4 minimum. A little bit more is okay, a little bit less will hurt performance.


Theoretical canon as follows:

Barrel inside diameter of .750inches

Chamber inside diameter of 1.50inches

Ideal piston travel is barrel id divided by 4.

So your piston should move .750"/4 or 0.1875" (3/16") before hitting your bumper. (Mouse pad, camping mat, etc.)

This would make your theoretical "ideal pilot volume" roughly

pi*r*r * .1875" or 3.14*.750*.750*.1875 = 0.3312cu.in.

Hint: Use this number in ggdt to size your pilot valve. Increase/decrease the pilot diameter until you eliminate piston bounce.


Okay, that's in an ideal world. In "our world", call it 1/4" of total piston travel, and a pilot volume of 0.44 cu.in.
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2394
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: Coodude26 » Wed Jul 30, 2008 12:52 pm

MrCrowley wrote:
Coodude26 wrote:Whats with the arrows at the end of the chamber?
And no one can tell you for sure if something will work or not because you haven't even built it yet.

The arrows show that the chamber is not to scale and will be longer i'm guessing.

He is wondering if the concept will work, if you understand physics you can tell if something will work before building it...idiot. :roll:



No need to insult me. I just didn't want him to get over-excited when a couple people tell him it would work, and then be careless with the construction.
  • 0

User avatar
Coodude26
Master Sergeant
Master Sergeant
 
Posts: 167
Joined: Sun Apr 20, 2008 1:03 pm
Reputation: 0

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'