mpmrla's .36 and .50 cal qev muzzleloader questions

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jonesy42
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Tue Jul 24, 2012 1:18 pm

Hi.., has anybody built the above muzzleloader's?,... i have a few questions?
Firstly, i have nearly all the parts that mpmrla has listed in his plans from his threads/diagrams etc. He uses a 250psi qev valve, but shoots at 300-400psi in his vids?, How is this possible
if the qev is 250psi rated? Do you mod them to take more psi? Also i was i thinking of
using a ninja slp regulator set at 300psi, so i can regulate air to the qev valve and get 10 shots out of my 3000psi paintball tank.. All answers appreciated, cheers guys.
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Tue Jul 24, 2012 2:37 pm

jonesy42 wrote:He uses a 250psi qev valve, but shoots at 300-400psi in his vids?, How is this possible
if the qev is 250psi rated? Do you mod them to take more psi?
A QEV rated to 250 psi won't explode at 251 psi, pressurised components usually have a generous safety factor built in which can be abused at your own risk. Members of this forum have taken standard QEVs to 500 psi and beyond. Doesn't mean it's 100% safe, but there's relatively low risk of something bad happening. The weak point is usually the piston/diaphragm, this will typically fail before the body shatters.
Also i was i thinking of using a ninja slp regulator set at 300psi, so i can regulate air to the qev valve and get 10 shots out of my 3000psi paintball tank.. All answers appreciated, cheers guys.
With an efficient design you can probably get away with a smaller chamber and therefore more shots per fill.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Tue Jul 24, 2012 9:27 pm

@jacksmirkingrevenge....Thanks for the info on the qev!, i was wondering if that was the answer. I only want to put an extra 50psi through the qev.... Also, is the "1/8 button vent valve"(for the pilot- trigger) the same as a relief valve you get on a standard shop compressor tire inflator or blow gun? Thanks.
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Tue Jul 24, 2012 11:58 pm

jonesy42 wrote:Also, is the "1/8 button vent valve"(for the pilot- trigger) the same as a relief valve you get on a standard shop compressor tire inflator or blow gun? Thanks.
It's basically like a blowgun.

If you want semi-auto though, you need to be thinking about three way valves.

Here's one: http://www.ebay.com/itm/PARKER-PNEUMATI ... 231e59cd8d

You can also consider slide valves: http://www.spudfiles.com/forums/semi-au ... 23626.html

If you don't use a three way valve, you will basically have to manually refill your chamber after every shot.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 1:02 am

@jacksmirkingrevenge... This is how im thinking of doing it : A 3000psi "spare air" scuba buddy bottle, i picked up second-hand on ebay. From there, screw in a ninja slp 300psi regulator. The other side of the regulator joins to a 1/2 street elbow and 1/2 nipple, to 1/2 inch 250psi alpha qev - point "A".... Qev point "P" will have a 1/2 - 1/8 reducer bushing, to 1/8 nipple, to 1/8 tee, to 1/8 button vent (pilot) valve etc..... If i just use it as a single - shot muzzleloader would this work?, as in the regulator "re-sends" another 300psi
fill of air to qev after each shot?
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Wed Jul 25, 2012 2:45 am

the way you describe it, it will never seal - QEV pistons allow air from the pilot to the chamber, but not vice versa, so you cannot fill from the chamber side unless you modify the piston.

Even if you could, it would not reset itself the way you describe it.

Read up a little on QEVs and three way valves, there is plenty of information on the forum to give you a better idea of how the setup works.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 3:53 am

@jacksmirkingrevenge.. :? Now you have really confused me! :lol:
So, what your saying is the paintball tank has to be filled from the pilot
side of the qev to work right?.. I can still put a fill connection on the pilot
end if need be, instead of filling it via the tank regulator.. Will it work
with the regulator in the air tank now?
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Wed Jul 25, 2012 4:50 am

Wait what?

http://www.spudfiles.com/spud_wiki/inde ... aust_valve

here'a a thought, quick sketch of your intended setup will help us go further ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 5:38 am

@jacksmirkingrevenge.... I can't do a diagram or post photos yet...
im using a sony ps3 to post .....You can see photos/diagrams of the
one im copying in "pneumatic cannon showcase"
under :"400 psi 150 fpe metal 50 cal muzzleloader qev cannon" by mpmrla.
Funnily enough, you left a comment on the thread too.
To see them in action, check out - Mathew simon on youtube. 8)
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Wed Jul 25, 2012 9:48 am

Note that mpmrla's launcher fills from the pilot side. What he does basically to get multiple shots is only release a small amount of pilot volume at a time with his push button valve, so that the valve reseals after he releases it.

This will work, but using a 3 way valve as a pilot being fed by a regulated air supply will give you much more consistent results.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 10:05 am

@jacksmirkingrevenge... im with you now!... any cannons you can
think of, with the 3 way pilot valve set-up? Where do the other 2 ports
of the 3 way valve join up too? Or are blocked off?.... I also checked
out the 3 way valves that you left in the link from your previous post as well.
Thanks heaps for all your help too. :D
Last edited by jonesy42 on Wed Jul 25, 2012 10:35 am, edited 1 time in total.
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Wed Jul 25, 2012 10:24 am

A couple of interesting examples built with imaginatively used off-the-shelf parts:

http://www.spudfiles.com/forums/semi-au ... 22363.html - this would need your paintball tank connected the QD.

http://www.spudfiles.com/forums/semi-au ... 24091.html

my slide valve tutorial: http://www.spudfiles.com/forums/semi-au ... 23626.html

wyz's even better one: http://www.spudfiles.com/forums/how-to- ... 24038.html

of course you don't really need a magazine system if you want to muzzle-load, just look at how the slide valves are used.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 10:51 am

@jacksmirkingrevenge....Nah, don't like the slide valves, to hard to make
it in to a nice trigger!.... With the 3 way pilot trigger valves a question?
1 port = qev
1 port = fill nipple
1 port = air chamber
Yes?
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Wed Jul 25, 2012 12:52 pm

jonesy42 wrote:@jacksmirkingrevenge....Nah, don't like the slide valves, to hard to make
it in to a nice trigger!.... With the 3 way pilot trigger valves a question?
1 port = qev
1 port = fill nipple
1 port = air chamber
Yes?
If you don't like slide valves there are other more ergonomic options, i linked to a pushbutton 3 way valve earlier.

one port is permanently open, this goes to your pilot area ("P" here: http://hosting.pbportal.de/ionguide/imgs/board/qev.gif ).

the other two ports are alternately open and closed.

one of these is connected to your air tank

the other is left open to the atmosphere.

To "A", you connect a smaller ("firing") chamber with enough volume to hold air for one shot.

To "R", you connect your barrel.

when the system is at rest, the connection to "P" is open allowing the main tank to fill and the QEV to seal.

When you push the button, this connection is closed, sealing off the main tank, and the pilot is then open to the atmosphere, meaning it will empty and fire the valve. This empties the firing chamber through the barrel.

When you release the button, the cycle is allowed to repeat.

Voila, semi-auto.
Last edited by jackssmirkingrevenge on Fri Jul 27, 2012 10:19 am, edited 1 time in total.
hectmarr wrote:You have to make many weapons, because this field is long and short life
jonesy42
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Wed Jul 25, 2012 8:18 pm

@jacksmirkingrevenge....I have orderd the Parker 3 way trigger valve you mentioned thanks.

Question: So,.. i need a smaller "firing chamber" to contain the supply of regulated 300
psi air for each shot?......... 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?
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