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CBHV: Masterclass entry

Posted: Sun Aug 28, 2011 2:44 pm
by Brian the brain
Edit: This is now my official Masterclass Challenge entry.

Image
The goal is to build a cannon that looks ( almost) factory made.
The challenge is not to beat each other, but rather to beat yourself and inspire others.
I hope to see many more entries.

Not yet a cannon but definately a showcase.

(In case you haven't read this the gun is now finished)

I finished the valve for my upcoming gun..
It uses the same principle as my " 35 bar pushbutton valve"

Normally a poppet style hammer valve has to overcome the pressure to open.
I extended the head into a piston and the housing into a cilinder.
The piston head seals into the bulletnose ( see picture) via an O-ring.

This illiminates the force pressure would normally excert on the front of the head almost completely.
The valve seat is only slightly larger than the piston diameter, making it pop open at the gentlest tap, yet providing massive flow.

This one offers me a 12 mm ( minus the center rod) diam. hole for the air to rush through.
Definately an improvement over traditional hammer valves and a breeze to " hammer"

This also means I won't need a massive hammer and spring to go bigbore.

Also, I think this valvedesign would be a very simple way for those with a lathe to upgrade their Crosman airguns to say... a 9mm beast! :wink:

That's why I could not keep this design from you guys.

The one way valve that will be used in the cannon can also be seen in the pic.

Enjoy!

Posted: Sun Aug 28, 2011 3:07 pm
by MRR
Nice :D

I've had nearly the same design like this in my head for quite some time but never bothered to actually build it due to the lag of 'proper' tools. :?

The only difference in my design would have been that the part on the left is actually balanced and that there would be a surface differential on the right to make it self cocking.

Posted: Sun Aug 28, 2011 3:07 pm
by jackssmirkingrevenge
Simple but effective, I like!

You know, since you need a weaker hammer to open it, that means that reloading for a semi-auto won't need much effort...

Posted: Sun Aug 28, 2011 3:14 pm
by Gippeto
Looks interesting...look forward to a video of it shooting. :)

Take notes of start and final pressures, average velocity for the shot string, number of shots and projectile mass, and we can compare the efficiency with the more traditional style valves. :)

1.25ft.lb/barcc is "working good" (1.25ft.lb for every cc of air @ atmospheric pressure.) I've seen some 9mm stuff hit 1.4ft.lb/barcc.

Posted: Sun Aug 28, 2011 3:15 pm
by Brian the brain
Jack...this thing could run on unregulated CO2... :D

Plenty of shots me thinks...

Just flip it under/over so a mag can be allowed from the bottom and autocock T-bolt style...

The reservoir tube could extend past the valve-striker allowing for an inline hammer ( with spring inside the tube)
Just let some gas pass the striker and...voila!
Pneumatic full auto MP5 in 9mm cal.

:D

Posted: Sun Aug 28, 2011 4:23 pm
by POLAND_SPUD
Normally a poppet style hammer valve has to overcome the pressure to open.
I extended the head into a piston and the housing into a cilinder.
great, now it's a spool valve :D

Looks promising
Pneumatic full auto MP5 in 9mm cal.
hmmm

Posted: Sun Aug 28, 2011 5:16 pm
by Moonbogg
Just because I don't understand it doesn't mean it don't sure look pretty!

Posted: Sun Aug 28, 2011 6:40 pm
by jhalek90
*drools* I WANT!!!!!

Looks very promising. Cant wait to the what BTB can make outta this beast.

Posted: Sun Aug 28, 2011 6:42 pm
by Hubb
jackssmirkingrevenge wrote:Simple but effective, I like!
And that's usually how it goes. Simplicity makes for the most effectiveness.

And my thoughts on the design:
:thumbright: :thumbright:

Posted: Mon Aug 29, 2011 2:18 am
by Crna Legija
I'm sure wyz2258 will be happy when he sees this.

Posted: Mon Aug 29, 2011 2:22 am
by LovableAirGuns
Im guessing this gun is going to be for the master-class challenge?

Good job iv nearly fished my valve.
Its a very good concept to :D

Posted: Mon Aug 29, 2011 2:27 pm
by Brian the brain
I've had nearly the same design like this in my head for quite some time

Something like 2 years? :D
we can compare the efficiency
Yeah...riiight...
Power..maybe...but she's a gas-guzzler...no where near efficient :D

She's meant to give a big boom...asking little in return.

the opposite if a woman actually... :wink:
now it's a spool valve
No!!!!!!!
Aarghhhh
:P
Simple but effective, I like!
And that's usually how it goes. Simplicity makes for the most effectiveness.
Hahahaha....

The simplicity is a result of going over the design again and again, eliminating parts, reconfiguring etc.. to make it simpler and more importantly, more compact.I had thought of this particular design fairly early on but I have reconsidered it conciderably....uhmmm :roll:


I started out with a counterpiston out the front of the chamber, then a counter piston in the back, with some introgate channels providing it with the required pressure.

It's a well thought out concept..of simplicity..

Posted: Mon Aug 29, 2011 3:19 pm
by MRR
Brian the brain wrote:
I've had nearly the same design like this in my head for quite some time

Something like 2 years? :D


No, not thaaaaat long :) but at the time when you introduced your balanced push button valve. The beauty of the concept is that you can do so much things with it, like pilot, 3-way, hammer valves and regulators.

Posted: Mon Aug 29, 2011 6:52 pm
by POLAND_SPUD
The beauty of the concept is that you can do so much things with it, like pilot, 3-way, hammer valves and regulators
you see I told ya - everything is a DCV
:D

Nahh but seriously - an air regulator is essentially just an air actuated 3 way valve


the simplicity is certainly there... the only question is how well it will perform as there are many things that have to be tweaked to offer both good performance and efficiency

ohh any idea what sort of loading mechanism could you use with it??

Posted: Tue Aug 30, 2011 3:26 am
by wyz2285
Crna Legija wrote:I'm sure wyz2258 will be happy when he sees this.
I´m sure very happy to see this :P I have been looking for hammer valve that opens with a weak spring at high pressure for a long time, good job :thumbright: I will make one simular to see how well it works :)