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 63 users online :: 4 registered, 1 hidden and 58 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

my first piston valve (picture and video)

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

my first piston valve (picture and video)

Unread postAuthor: far_cry » Mon May 11, 2009 10:19 am

at last i build a piston valve and he work great
it's 3/4" T copper (or bras !!)
the piston made from wood , sweeper stick :D turn it on a lathe and he is about 18mm

and here is the video hoe fast he dump the air. the pressure is about 130 psi
dont forget to watch the video in HD .you know how :roll: :roll: :roll:
[youtube]http://www.youtube.com/watch?v=m1JjibL8pd0[/youtube]
  • 0

Attachments
Picture 001 (Medium).jpg
the piston
Picture 001 (Medium).jpg (33.78 KiB) Viewed 3279 times
Picture 011 (Medium).jpg
Picture 012 (Medium).jpg
Picture 005 (Medium).jpg
Last edited by far_cry on Fri May 22, 2009 5:04 pm, edited 1 time in total.
ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Unread postAuthor: Technician1002 » Mon May 11, 2009 12:45 pm

Congratulations on getting it right so it pops open. Nice home built QEV.
:D
  • 0

User avatar
Technician1002
Chief of Staff
Chief of Staff
 
Posts: 5190
Joined: Sat Apr 04, 2009 11:10 am
Reputation: 14

Unread postAuthor: Gippeto » Mon May 11, 2009 2:01 pm

Very nice job Far Cry. :)

You may have some trouble with the sealing face being retained at higher pressures, but only time (and pressure) will tell for sure.

You did a nice job rounding the piston seat too. :D

:thumbright: :thumbright:
  • 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: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: littlebro05 » Mon May 11, 2009 2:23 pm

Your Piston looks friggin' beautiful lol. It' looks so cleanly built.

Nioce Job.
  • 0

It's Nerf or Nothing.

Don't start crying when I play this as my hobby, Paintball, Airsoft and Nerf are equally good hobbies, except you can play Nerf in public. Good day! Hmph!
User avatar
littlebro05
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 417
Joined: Wed Oct 17, 2007 5:04 am
Reputation: 1

Unread postAuthor: VH_man » Mon May 11, 2009 6:01 pm

Gorgeous!

Could probably cut down on Pilot volume in the back, And use a smaller Ball valve, But otherwise I'm Envious.

Whatcha gonna put it on?
  • 0

User avatar
VH_man
Major General
Major General
 
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Reputation: 1

Unread postAuthor: far_cry » Mon May 11, 2009 6:19 pm

Technician1002 wrote:Congratulations on getting it right so it pops open. Nice home built QEV.
:D

thank you technicaian . you the Technician


littlebro05 wrote:Your Piston looks friggin' beautiful lol. It' looks so cleanly built.

Nioce Job.


i love my work to look beautiful so this take time
thank you

Gippeto wrote:Very nice job Far Cry. :)

You may have some trouble with the sealing face being retained at higher pressures, but only time (and pressure) will tell for sure.

You did a nice job rounding the piston seat too. :D

:thumbright: :thumbright:


and Gippeto thanks for the compliment
and what you did mean by You may have some trouble with the sealing face being retained at higher pressures
so may i have some leaks or the seal face stuck ? if so what i can do,, and the piston is temporary from wood .i will turn one from hard plastic or aluminium
  • 0

ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Unread postAuthor: far_cry » Mon May 11, 2009 6:28 pm

VH_man wrote:Gorgeous!

Could probably cut down on Pilot volume in the back, And use a smaller Ball valve, But otherwise I'm Envious.

Whatcha gonna put it on?


Envious :o :o you can do this too, its easy
and the pilot volume is big , i know i just test the piston valve ,it's a temporary install.
and the pilot valve , i want to make i hammer valve to pilot the piston :twisted: :twisted: like Gippetos canon
the air gun will take some time to build the stock mostly
  • 0

ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: Gippeto » Mon May 11, 2009 6:48 pm

[quote="Gippeto"]You may have some trouble with the sealing face being retained at higher pressures quote]

What I mean;

With my bbgun, the teflon seat was "sucked" right out of the hole it was pressed into. This would seem to demonstrate that the flow creates a vacuum at the front of the piston.

Your sealing face "may" be pulled over the head of the screw by the flow.

If this does present itself as a problem, you could turn a washer from teflon or some other softer plastic (hdpe?) to use as the sealing face.

Harder sealing surfaces take more work to be successful, but also yield some small improvements in performance. :D

The screw should then be entirely adequate.(This was the case with my bbgun.) :D
  • 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: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: far_cry » Mon May 11, 2009 7:01 pm

i understand , the seal face will sucked into the barrel with high pressure because the strong vacuum
i will find solution after all

and , can this piston valve handle 1000 psi ? agnor the seal face issue

and i have alittle problem the long part ,seat face i put allot of teflon but he still leak what can i do
  • 0

Last edited by far_cry on Mon May 11, 2009 7:08 pm, edited 1 time in total.
ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Unread postAuthor: VH_man » Mon May 11, 2009 7:06 pm

Id be weary of 1000, But 500 Definetly. My copper one holds 500.

Cant wait to see what this thing will be able to do.
  • 0

User avatar
VH_man
Major General
Major General
 
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Reputation: 1

Unread postAuthor: far_cry » Mon May 11, 2009 7:17 pm

the leak is here what can i do ?
Image
  • 0

ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Unread postAuthor: Gippeto » Mon May 11, 2009 7:33 pm

If you have access to a product called "Loctite", the blue variety should provide a seal.

Clean off the teflon tape, apply the loctite and tighten the pieces together.

Then leave it for a day or so. It'll seal.

500psi I think would be fine. Since I've not tested any brass/bronze fittings, I am hesitant to suggest more.

The "turned" fittings would be fine. It's the casted ones you need to watch out for.(the tee)

What do you estimate the minimum casting thickness to be?

Can you provide accurate dimensions as well?
  • 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: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: far_cry » Mon May 11, 2009 8:05 pm

Gippeto wrote:What do you estimate the minimum casting thickness to be?

Can you provide accurate dimensions as well?

2-3 mm APPROX the T thickness. if the T dont have enofh thickness i will replace it with stell or another copper T but with a very good brand T

dimension i am not in the home right now but its standard 3/4" T ,
  • 0

ImageImage
User avatar
far_cry
Donating Member
Donating Member
 
Posts: 317
Joined: Wed Aug 20, 2008 3:59 pm
Reputation: 0

Unread postAuthor: Mitchza89 » Mon May 11, 2009 10:44 pm

Very nice gun Far_Cry. I love it. Be careful with the piston though. I used lathed timber for a while until the wood swelled from the condensed air and vapor and the piston completely got stuck.

I solved this problem by putting on a coating of "super glue" to more or less seal it.

I now use hand machined aluminum. It's very easy to machine on a wood lathe, it just takes a little more time.
  • 0

Image
User avatar
Mitchza89
Brigadier General
Brigadier General
 
Posts: 1056
Joined: Tue Jan 09, 2007 12:05 am
Reputation: 0

Unread postAuthor: Carlman » Mon May 11, 2009 11:02 pm

Sweet mate! I have to post up my brass piston, brass FTW!
  • 0

Image
Aussie spudders unite!!
User avatar
Carlman
Major General
Major General
 
Posts: 1618
Joined: Sat Nov 24, 2007 1:18 am
Location: Western Australia
Reputation: 0

Next

Return to Pneumatic Cannon Database

Who is online

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

Reputation System ©'