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 48 users online :: 3 registered, 0 hidden and 45 guests


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

Registered users: Bing [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 piston valve work?

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 piston valve work?

Unread postAuthor: Gunner » Sun Oct 21, 2007 10:15 am

Here is the picture,any suggestions?
  • 0

Attachments
Piston Valve.JPG
Piston Valve.JPG (13.71 KiB) Viewed 541 times

Gunner
Staff Sergeant
Staff Sergeant
 
Posts: 111
Joined: Sun Oct 21, 2007 9:05 am
Reputation: 0

Unread postAuthor: potatoflinger » Sun Oct 21, 2007 10:37 am

Yeah, it should work, but you should check the wiki before you make a post like this. The type of piston you are thinking of is a piston in a tee, and ti has been done many times before. I'm not trying to flame you, but it is a common mistake that new members make (I did it a few times)
  • 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: Gunner » Sun Oct 21, 2007 11:03 am

OK,but what does it matter when piston is in tee? :wink:
  • 0


Gunner
Staff Sergeant
Staff Sergeant
 
Posts: 111
Joined: Sun Oct 21, 2007 9:05 am
Reputation: 0

Unread postAuthor: SpudBlaster15 » Sun Oct 21, 2007 11:57 am

This valve will work, but will require A LOT of cutting to remove the inner lip of the T fitting in order to allow a piece of pipe to pass through far enough to allow the piston to sit as forward in the T as you have sketched. My suggestion is to make this piston significantly longer, which will cut down on pilot volume, and reduce the amount of cutting required.
  • 0

People should not be afraid of their governments. Governments should be afraid of their people.
User avatar
SpudBlaster15
Major General
Major General
 
Posts: 2385
Joined: Wed Oct 18, 2006 11:12 pm
Location: Canada
Country: Poland (pl)
Reputation: 3

Unread postAuthor: Bluetooth » Sun Oct 21, 2007 12:52 pm

It will work, but your piston is going to have to be very short because the bushing that you would put in the end to plug it up will take up most of the space. SpudBlaster15, you do not need to cut out anything, or slide a pipe in. It would let the piston slide back further, but is not needed.
  • 0

User avatar
Bluetooth
Brigadier General
Brigadier General
 
Posts: 863
Joined: Tue Jun 27, 2006 7:57 am
Reputation: 0

Unread postAuthor: Gunner » Sun Oct 21, 2007 1:05 pm

OK,how about now,better? :)
  • 0

Attachments
Piston Valve.JPG
Piston Valve.JPG (12.72 KiB) Viewed 496 times

Gunner
Staff Sergeant
Staff Sergeant
 
Posts: 111
Joined: Sun Oct 21, 2007 9:05 am
Reputation: 0

Unread postAuthor: spanerman » Sun Oct 21, 2007 1:08 pm

yup



message to short
  • 0

Image

spanerman
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 438
Joined: Sun Sep 17, 2006 2:54 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: SpudBlaster15 » Sun Oct 21, 2007 1:15 pm

Bluetooth wrote:It will work, but your piston is going to have to be very short because the bushing that you would put in the end to plug it up will take up most of the space.


Exactly why I suggested a design that allows the piston to slide inside a piece of pipe rather than the T itself.
  • 0

People should not be afraid of their governments. Governments should be afraid of their people.
User avatar
SpudBlaster15
Major General
Major General
 
Posts: 2385
Joined: Wed Oct 18, 2006 11:12 pm
Location: Canada
Country: Poland (pl)
Reputation: 3

Unread postAuthor: MrCrowley » Sun Oct 21, 2007 4:39 pm

Damn I wish we had some sort of built in paint program when posting.

Anyway, what most people do is sleeve the tee with the same diameter pipe as the tee itself. You only need about 2" of this pipe but you should measure it beforehand.

Now what you need is a reducing threaded plug, this means it goes inside the tee, but reducers down to say 1/2" threads, where you can attach your pilot setup.

Find out how much room the plug takes up in the tee, and find how long the tee's socket is(from the opening of the tee socket(where the pilot setup will be) to the 'lip' which is just before the opening socket to the bottom of the tee) This will only be about 5" long.

So say your plug is 3" long, that means you need some pipe to sleeve the tee which is only 2" long. Cut the pipe, jam it in the tee, and makea piston for it.

Try and have the seat(barrel) a bit further forward then you have it now, and then you need to make a piston which fits inside the sleeved tee, is lnog enough to seal against the seat(barrel) without the piston coming to far forwards(you will have piloting problems if this happens) and so the piston has enough room to be pushed back when the piston fires.

Here's a quick diagram:

Black = Tee
Green = sleeved pipe
Maroon = 'lip' inside tee
Grey = Reducing threaded plug
Brown - Pilot setup
Yellow = fill valve
red circle = ball valve(pilot valve)
Orange = piston(the grey is a bolt and the washer holding on the sealing face)
Purple = Barrel
Sky Blue = sealing face

Image
  • 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: Gunner » Mon Oct 22, 2007 1:01 am

OK,thanks for the picture and suggestions. :wink:
  • 0


Gunner
Staff Sergeant
Staff Sergeant
 
Posts: 111
Joined: Sun Oct 21, 2007 9:05 am
Reputation: 0

Unread postAuthor: Tsukiten » Mon Oct 22, 2007 2:10 pm

Hey hey hey hey guys
This can't be right...doesn't all the compressed air need a surface to push the piston back against? Or does it work on a different way...?


Edit: Oh sorry I think you guys meant that the air can flow to the front of the piston to push it back, my bad...
  • 0

If you experience glitches and/or distortions in the space-time in close proximity to yourself, the above post may be an alteration of the truth.

Tsukiten
Staff Sergeant
Staff Sergeant
 
Posts: 115
Joined: Sun Aug 12, 2007 3:39 am
Reputation: 0

Unread postAuthor: watto » Tue Oct 23, 2007 4:33 am

As of today I have my own working piston cannon so I'm officially allowed to advise people lol, I found the main things are to make sure the end of the barrel that contacts the piston is perfectly level and smooth, I used some really fine wet and dry sandpaper then buffed it. Also don't leave much space behind the piston you only need a bit more than 1/4 of the barrels diameter. Make sure you get a big pilot valve not just a blow gun. Don't drill an equalization hole in the piston the air will get around the outside no matter how perfect the fit is. Make sure you can remove the piston so you can fix it if you need to. And most of all give the pipe glue 48 hours to dry not 24. I have to buy and glue a new plug because I didn't leave the glue long enough before testing it.

Good luck
  • 0

User avatar
watto
Captain
Captain
 
Posts: 327
Joined: Wed Dec 13, 2006 5:47 pm
Location: Australia
Reputation: 0

Unread postAuthor: chaos » Tue Oct 23, 2007 4:51 am

In the interests of correct information for searching users;


Make sure you get a big pilot valve not just a blow gun.


not so true


Don't drill an equalization hole


not so true


all the rest is good tho mate, knowledge is power!!
  • 0

User avatar
chaos
Brigadier General
Brigadier General
 
Posts: 1205
Joined: Wed Jan 17, 2007 8:31 am
Reputation: 0

Unread postAuthor: watto » Tue Oct 23, 2007 6:39 am

chaos wrote:
Make sure you get a big pilot valve not just a blow gun.


not so true


Well generally the bigger the pilot the better the gun will work within reason.

chaos wrote:
Don't drill an equalization hole


not so true


Unless your machining a piston with o-rings, which this guy isn't, your not going to need an equalization hole...
  • 0

User avatar
watto
Captain
Captain
 
Posts: 327
Joined: Wed Dec 13, 2006 5:47 pm
Location: Australia
Reputation: 0

Unread postAuthor: Gunner » Tue Oct 23, 2007 7:28 am

What is the right size tee because I am gonna use barrel which ID is 20mm and outer diameter something 22mm?Something 30-40mm?
  • 0


Gunner
Staff Sergeant
Staff Sergeant
 
Posts: 111
Joined: Sun Oct 21, 2007 9:05 am
Reputation: 0

Next

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'