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 68 users online :: 4 registered, 0 hidden and 64 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

QEV + slide valve multi shot - HELP!

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

QEV + slide valve multi shot - HELP!

Unread postAuthor: encohen » Sat Mar 11, 2017 7:26 pm

Hey,

I'm new to airguns and I've decided to build one.
I'm still testing for an effective setup, and was hoping you can help.

My first version was a 500cc soda stream air reservoir with a 1\2" ball valve (powered by a spring) and a 1\2", 38" long galvanised steel tube as a barrel. it was a single shot and it was really powerful. it could completely penetrate a 1" plywood from 15 meters shooting 100 grains nail dart at 160 PSI.

it was nice, but i wanted to upgrade it and get multi shots per fill, so i got a QEV and slide valve and connected them to the same barrel and air reservoir, as shown here:

Capture.PNG




so i get more shots per fill now, but the power has decreased dramatically, the same nail dart does not penetrate the plywood.

volumes:
air reservoir: 500cc
firing chamber: 50cc
barrel: 120 cc
--------------------------------------------------------
so after doing some reading in this forum i have come to understand i need to make some changes.
I think these are my options:

1. increasing firing chamber volume
2. decreasing barrel volume
3. increasing air pressure (got a new shock pump - 600 PSI)

which will make the most impact?
it there any better options?

Thanks :)
  • 0

I have tasted the maggots in the mind of the universe, but I was not offended.For I knew I had to rise above it all, Or drown in my own ***
User avatar
encohen
Specialist
Specialist
 
Posts: 40
Joined: Thu Mar 09, 2017 4:36 am
Country: Netherlands (nl)
Reputation: 4

Re: QEV + slide valve multi shot - HELP!

Unread postAuthor: jackssmirkingrevenge » Mon Mar 13, 2017 2:26 pm

The best idea is to first download GGDT:

http://www.thehalls-in-bfe.com/GGDT/

This excellent program will allow you to virtually model the parameters (chamber volume, pressure, barrel length etc.) to give you a very good idea of what will give you optimal performance.

Higher pressure is definitely the parameter that will give you the biggest boost. Also reducing your barrel length will almost always reduce performance unless you have a really tiny firing chamber or are using extremely low pressure.

(got a new shock pump - 600 PSI)


It will take you forever to pressurize that size of bottle to 600 psi with a shock pump, consider a fridge compressor:

how-to-database/topic11866.html
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24449
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 80

Re: QEV + slide valve multi shot - HELP!

Unread postAuthor: encohen » Sun Mar 19, 2017 1:32 pm

That's what i came up with

  • 1

Last edited by jrrdw on Sun Mar 19, 2017 5:37 pm, edited 1 time in total.
Reason: Embedded video.
I have tasted the maggots in the mind of the universe, but I was not offended.For I knew I had to rise above it all, Or drown in my own ***
User avatar
encohen
Specialist
Specialist
 
Posts: 40
Joined: Thu Mar 09, 2017 4:36 am
Country: Netherlands (nl)
Reputation: 4

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'