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 61 users online :: 6 registered, 0 hidden and 55 guests


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

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

new to this and a little confused about valves

This area is for the discussion of BB or airsoft sub machine guns, and or other small arms such as pellets.
Sponsored 
  • Author
    Message

new to this and a little confused about valves

Unread postAuthor: mattyg » Tue Nov 19, 2013 11:18 pm

hey all Im new here and have what is probably a very noob question.
I have been designing a semi auto based on a video I found on you tube
by wyz
the design integrates a blow forward bolt into a sleeved barrel and uses a qev to discharge air= down the barrel
now I dont want to use a slide valve as I want a trigger system that is more realistic.
i was considering using a blow gun but then the air has no where to vent
ive also heard if I put a little pin sized hole in the outer edge of the QEVs piston that it will allow it to vent and i would be able to use a blower.. My only concern with that is Would that reduce the posible rate of fire???
and if it does reduce the rate of fire what alternatives are there.



Edit: just found this on ebay but its only rated to around 110 psi alot lower than i want to go
http://www.ebay.com.au/itm/1-4-PT-Air-Inlet-3-Way-Two-Position-Momentary-Mechanical-Valve-MV322PP-/390580128004?pt=AU_Business_Industrial_Industrial_Supply_MRO&hash=item5af063c904&_uhb=1
  • 0


mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: Biopyro » Sat Nov 23, 2013 12:53 pm

Hi mattyg, I'm having a little trouble working out what you're asking. You want to know what kind of valve is best to trigger a QEV for semi-auto use?

Perhaps you could post the video you're basing your design on? Also I recommend writing your posts in a program like microsoft word as it does all the grammar stuff and makes it easier to read posts :)
  • 0

Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. -Benjamin Franklin
User avatar
Biopyro
Colonel
Colonel
 
Posts: 656
Joined: Fri Aug 04, 2006 5:32 am
Location: UK
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: POLAND_SPUD » Sat Nov 23, 2013 1:27 pm

You want something like this >>
Image
It's called a 3 way valve
You want one that's normally open not normally closed (though some are universal)

You can either buy one with manually operated (with a lever/button) or one actuated by a solenoid and use a push button switch
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Re: new to this and a little confused about valves

Unread postAuthor: mattyg » Sat Nov 23, 2013 6:45 pm

here is the vid I was following


I was thinking a 3 way valve but I though normally open and normally closed didn't particularly matter with a 3 way valve as you can just switch which port you use for exhaust and charge????
Maybe I don't understand how they work properly!
I was looking at the valve that i posted the ebay link for as a possibility but it will only handle around 110psi and I wish to go much higher than that.
  • 0

Last edited by jrrdw on Sun Nov 24, 2013 3:45 am, edited 1 time in total.
Reason: Fixed video.

mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: jackssmirkingrevenge » Sun Nov 24, 2013 6:52 am

pneumatic-cannons/topic25108.html?hilit=atmosphere%20qev#p365630

An explanation of how the whole 3-way valve setup works which you might find useful.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Re: new to this and a little confused about valves

Unread postAuthor: mattyg » Sun Nov 24, 2013 6:00 pm

Yep thats exactly how I thought it worked.

jackssmirkingrevenge you put up a link to this valve
http://www.ebay.com/itm/1-8-PT-Female-Thread-Two-Position-Three-Way-Flow-Control-Pneumatic-Gas-Valve-/310575456187?pt=Pneumatic_Hydraulic_Valves_Parts&hash=item484fbd5fbb

This is a lot more compact than the valve I was looking at and has a slightly higher pressure rating 1MPA (145psi)
but this still seems fairly low for what I am planning.
has anyone attempted to run higher pressures though these valves??
  • 0


mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: jackssmirkingrevenge » Mon Nov 25, 2013 3:05 am

mattyg wrote:This is a lot more compact than the valve I was looking at and has a slightly higher pressure rating 1MPA (145psi)
but this still seems fairly low for what I am planning.
has anyone attempted to run higher pressures though these valves??


They're upside down :-/ start here and read on.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Re: new to this and a little confused about valves

Sponsored

Sponsor
 


Re: new to this and a little confused about valves

Unread postAuthor: mattyg » Mon Nov 25, 2013 4:42 am

well that sucks they were looking good

damn it they looked so promising
  • 0

Last edited by jrrdw on Tue Nov 26, 2013 9:19 pm, edited 1 time in total.
Reason: Double posting.

mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: Ragnarok » Mon Nov 25, 2013 7:39 am

It is possible to find "normally closed" valves though, that just ain't one.

If it doesn't actually clearly say so in the product text, an understanding of pneumatic symbols (ISO 1219-1 is the most common standard) will probably get you through.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Re: new to this and a little confused about valves

Unread postAuthor: POLAND_SPUD » Mon Nov 25, 2013 7:53 am

technically it's it possible to use a normally closed valve too. You just have to build a simple trigger system that keeps it pressed when the trigger is in normal position. Damn it hard to explain it using words so here's a diagram

The added advantage is that NC valves are easier to get and you can make a more comfortable trigger
  • 0

Attachments
madiagramzrszittyIknow.JPG
madiagramzrszittyIknow.JPG (36.67 KiB) Viewed 1717 times
Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Re: new to this and a little confused about valves

Unread postAuthor: jackssmirkingrevenge » Mon Nov 25, 2013 12:19 pm

Yep, brian suggested something similar in the original thread.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Re: new to this and a little confused about valves

Unread postAuthor: mattyg » Mon Nov 25, 2013 11:24 pm

Yep I saw that I was of the same thought as you though. If possible I would rather use off the shelf item.
but this is not my biggest concern.
My biggest concern remains the relatively low pressure rating of these valves.
  • 0


mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: jackssmirkingrevenge » Tue Nov 26, 2013 9:58 am

What pressure do you intend to fire at? These are probably good for at least 300 or so psi.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Re: new to this and a little confused about valves

Unread postAuthor: mattyg » Tue Nov 26, 2013 4:35 pm

I was intending on running around 300 psi
if I run the valve at those levels will it loose reliability or shorten its lifespan?
I am willing to pay more for a higher rated valve i just cant find any
  • 0


mattyg
Private
Private
 
Posts: 7
Joined: Tue Nov 19, 2013 11:06 pm
Country: Australia (au)
Reputation: 0

Re: new to this and a little confused about valves

Unread postAuthor: T_Money » Wed Nov 27, 2013 2:49 pm

  • 0


T_Money
Private
Private
 
Posts: 17
Joined: Sat Jun 29, 2013 12:22 pm
Reputation: 0

Next

Return to BB/Airsoft/Pellet Gun Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], Majestic-12 [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'