Page 2 of 3

Posted: Thu Jul 26, 2012 12:26 am
by jakethebeast
Mpmrlas version has that hose sticked to the bacl of the QEV, that fills the airtank after every shot. So the air chamber is the firing chamber

Posted: Thu Jul 26, 2012 12:33 am
by jackssmirkingrevenge
jonesy42 wrote:Question: So,.. i need a smaller "firing chamber" to contain the supply of regulated 300 psi air for each shot?.........
If you are using a three way valve as an air feed/pilot valve as described above, yes.

Here's an exhaustive explanation of what's happening, in this case using a coaxial piston valve but the concept is the same:

Image

The slide valve is basically a three way valve.

A three way valve has three ports, which we will call A, B and C

There are two possible paths, AB (with C blocked off) and AC (with B blocked off)

A is connected to the pilot area of the piston valve, QEV in our case

B is connected to your paintball tank

C is simply left open to the atmosphere.

At rest, the three way is in position AB. This means your reservoir is filling the launcher chamber.

When the trigger is pulled, the valve switches to position AC. This means the reservoir is blocked off, and is no longer filling the pilot and chamber, while the pilot is exhausted to the atmosphere, which fires the launcher.

Once the trigger is released, the valve goes back to AB, refilles the pilot and chamber and the cycle can be repeated.

[youtube][/youtube]

:D
I didn't see the "firing chamber" in mpmrla's version?

Using the 3 way valve and paintball regulator in the air tank , would it not just "take"
the regulated 300 psi air from the air tank and primed pilot line , dump that air
and recharge to another 300 psi after each shot, without the need of a "firing chamber"
to "hold" the air?
Not sure if you're quite getting what's going on, have a read through the above and see if it's a bit clearer.

Posted: Thu Jul 26, 2012 9:01 am
by jonesy42
I hear what your saying in your slide valve/qev diagrams!... but i need to look at
it with a diagram of the parker 3 way pilot trigger you recomended,
connected to the alpha 1/2 inch qev i got,.. and a paintball tank with the
300psi reg fitted,,and also the "firing chamber" you mentioned,

Also,.. a diagram of how you would integrate these"hop-ups" into mpmrla's
version with relevant fittings / connectors, needed to complete it etc.

Now,... that would be helpful!,... and don't forget im from noob school :roll:

Posted: Thu Jul 26, 2012 3:02 pm
by jackssmirkingrevenge
jonesy42 wrote:Now,... that would be helpful!,... and don't forget im from noob school :roll:
at the risk of being too helpful, something like this ;)

Posted: Fri Jul 27, 2012 8:22 am
by jonesy42
@jackssmirkingrevenge... Works for me mate, (the diagram that is).. let me get some more parts organised/delivered and watch this space!...."I'll BE BACK"...with some pics n stuff of finished product...

Your info has been invaluable and is muchly apreciated! (even though it came down to one diagram really) my fault lol :roll: :shock:

PS,... at the risk of sounding stupid, (whoops to late), whats the best thing to use for my
"tank" firing chamber in the diagram?

Posted: Fri Jul 27, 2012 10:08 am
by jakethebeast
Galvanized plumbing parts would look quite nice, be easy to work with and has nice pressure capabilities, and they were also used in the video. Others like extinguishers or paintball tanks could also be used

Posted: Fri Jul 27, 2012 10:28 am
by jackssmirkingrevenge
jonesy42 wrote:PS,... at the risk of sounding stupid, (whoops to late), whats the best thing to use for my
"tank" firing chamber in the diagram?
You don't need too much volume, so as jake suggested glavanised fittings would be perfect.

modded the diagram slightly to show it more clearly, the valve is shown at rest but the detail in the box shows both rest and fired positions.

Posted: Fri Jul 27, 2012 4:25 pm
by jonesy42
Thanks guys :lol:

Posted: Sat Jul 28, 2012 5:34 am
by jonesy42
Will threaded 1/2 inch pipe with end cap about 100mm long be okay for
the firing chamber?....bigger or smaller than 100mm?, thanks.

Posted: Sat Jul 28, 2012 9:42 am
by jackssmirkingrevenge

Posted: Sat Jul 28, 2012 10:54 am
by jonesy42
I noticed the parker 3 way valve is 150psi rated... Am i not
going to be putting 300psi through it? Or does it work the same as
when you explained the qev? You can put a little more through than
its rated for- and all good? - See -, i have been paying attention a
little bit. :lol:

Posted: Sat Jul 28, 2012 11:41 am
by jackssmirkingrevenge
jonesy42 wrote:I noticed the parker 3 way valve is 150psi rated... Am i not
going to be putting 300psi through it? Or does it work the same as
when you explained the qev?
Pretty much

Posted: Sat Jul 28, 2012 11:56 am
by Gippeto
Jack....I think you've earned this... :)

Image

Posted: Sat Jul 28, 2012 12:03 pm
by jonesy42
I can't download that pressure converter you linked for some reason?

Should i just multiply the example conversion page of 100psi x3 to
get my firing tank size?... Looks like its going to be huge, going off
the 100psi calculation?

Posted: Sat Jul 28, 2012 12:10 pm
by jackssmirkingrevenge
Gippeto wrote:Jack....I think you've earned this... :)
"Golden spoon" sounds like something you would do with a lady who is into watersports after the action is over :D

*ahem*
I can't download that pressure converter you linked for some reason?
It's a program that will allow you to virtually model your launcher, and tell you how much power you will get for a given chamber size. Make the effort to install it, it's an extremely useful tool to use before commiting yourself to a build.