My project. .50 cal.

[FarmerDanz]

Hey everyone. My name is Dan I am from Coquitlam BC. I saw a video for a Sam Yang Dragon Claw and thought I could make something that would do about the same. I build, machined, welded and made everything you see! I am like a proud Daddy.

The last few things I need to do to complete the unit is a trigger and sear setup and furniture. The trigger will probably be a pin in a guide with a single stage trigger that releases the hammer when pulled down.

The unit is built to handle 4000psi but will be capped at what ever hits 500fps, until my PAL arrives. Haha.

Its got a 30 inch smooth bore barrel. I may rifle it with a rifling button if I find a nice piece of HSS over .5" dia. The rear is where the HPA tank screws on, which should put the trigger around 14" from the rear of the stock.


Check out some pics. If anyone has any questions or comments please do so!

A good overall view with no HPA tank or furniture.






A nice closer view of action.



Another overall view.




And a nice shot of the loading breech and hammer cock arm.

[wesb2007]

Cool! I'm unfamiliar with that kind of set up so forgive me for what is probably a dumb question. How does the air get transferred to the barrel behind the pellet when it's set up over the hammer area?

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[FarmerDanz]

There is an air transfer tube that is welded to the barrel. Its a 1/2in OD 5/16in ID tube I machined an o ring relief into.

That air transfer tube sits inside of an aluminum valve assembly that has a 1/2" hole for the air transfer tube, sealed by the o ring.

The hammer flies back towards the valve, strikes the valve pin, drives the valve open, air comes from the HPA tank into the valve, and up into the barrel behind the projectile.

Super simple stuff!! Youtube the Sam Yang Dragon Claw, mine works VERY similarly, the major difference is the Dragon Claw has its air tanks ahead of the action so you cock the hammer back towards you. I decided to use the 13ci HPA tank as a stock and to make a shoulder pad and adjustable cheek rest that snugs down on the HPA tank.


Edit; next time I have it apart I will take some more pictures for everyone to see. Gun porn is always fun!

[Ace]

very neat idea and setup...little confused from the above comment you made about the hammer strike
please clarify...are you saying that the hammer will somehow be strikes the valve pin on the 13ci tank...
looking forward to the finished project and how the rest of it comes together...

[MisterJ]

Nice work. So to cock it, do you push the arm forward?

[FarmerDanz]

very neat idea and setup...little confused from the above comment you made about the hammer strike
please clarify...are you saying that the hammer will somehow be strikes the valve pin on the 13ci tank...
looking forward to the finished project and how the rest of it comes together...

Ah yes I can see how my wording is a little wonky!

Let me try again.

The HPA tank has a female thread, which you see sticking out the back of the action. This connects the air supply to the actual gun.

That threaded adapter has a male thread on each end, one into the HPA tank, and one which screws into the aluminum valve assembly, which sits inside the action right at the rear.

The aluminum valve assembly is made up of an aluminum body, with a stainless valve pin and head. The SS valve moves towards you when its struck, because thats where the air supply is. The Dragon Claw has the air tanks on the other side of the hammer, so the valve in that device moves away from you when its actuated. I dont even know why I mentioned it. I guess it was a big deal for me when I was designing this thing, because for some reason cocking a hammer by pushing it away from you feels weird. Id way rather have a pull hammer arm but I dont want the thing to be ultra front heavy by having the air tanks up front instead of doubling as a stock like in my design. A trade off I guess!

Nice work. So to cock it, do you push the arm forward?

Yes, exactly. Weird eh? We will see if its a deal breaker.


Right now its got some dummy springs in there for testing and mocking up. You can see its pushed back and resting on the SS valve just waiting to be used!



I found this pic on my cell phone. This should explain it pretty good, maybe even worth 1000 words?

(omg so Canadian half metric half sae im ashamed lol)

[Ace]

Ok ...now im a little more confused... lol
so let me get this straight your going to mount the tank directly onto the threaded end behind
the gun as you said and also act as a stock...very similar in design as the air force condor...correct..?
but if you remove the Reg assembly from the 13ci tank in order to mount it to your threads...
How will you be re filling the tank when you have no more fill nipple...?

[FarmerDanz]

Ok ...now im a little more confused... lol
so let me get this straight your going to mount the tank directly onto the threaded end behind
the gun as you said and also act as a stock...very similar in design as the air force condor...correct..?
but if you remove the Reg assembly from the 13ci tank in order to mount it to your threads...
How will you be re filling the tank when you have no more fill nipple...?

Excellent question and even better example of a design that is similar. The Airforce guns are even better than mine, because the valve is probably hollow (i assume) and inline. IMHO, thats the way to go! Maybe one day I will try. Many months ago when I dreamed this up, my very first sketches were with a single tube design and a hollow valve. But the valve was so intense and hard to plan out, just too complex for me to figure out at the time. So I went with a regular old poppet valve design, almost exactly like you see in an automotive engine. The valve, guide, and valve stem seal are all from a Honda engine.

So the steel piece you see coming out the guns rear isnt quite done. It still needs some ports added to it, 1/8NPT. One for filling and one for a gauge. I should probably add one to release pressure just in case. Maybe that one will point away from your face. Hahah!


Also I should mention, I havent even gotten to the stage where I add air. I am worried, that because the orifices are so large, even at 160psi, the thing will rocket launch projectiles at a VERY high speed. So at this point, an expired HPA tank with a schrader valve would do the trick for some initial trial and error testing.

[Ace]

Ok ...now im a little more confused... lol
so let me get this straight your going to mount the tank directly onto the threaded end behind
the gun as you said and also act as a stock...very similar in design as the air force condor...correct..?
but if you remove the Reg assembly from the 13ci tank in order to mount it to your threads...
How will you be re filling the tank when you have no more fill nipple...?

Excellent question and even better example of a design that is similar. The Airforce guns are even better than mine, because the valve is probably hollow (i assume) and inline. IMHO, thats the way to go! Maybe one day I will try.

So the steel piece you see coming out the guns rear isnt quite done. It still needs some ports added to it, 1/8NPT. One for filling and one for a gauge. I should probably add one to release pressure just in case. Maybe that one will point away from your face. Hahah!


Also I should mention, I havent even gotten to the stage where I add air. I am worried, that because the orifices are so large, even at 160psi, the thing will rocket launch projectiles at a VERY high speed. So at this point, an expired HPA tank with a schrader valve would do the trick for some initial trial and error testing.

Ok so your going to ad a fill NP and a gauge to the end section of the rear tube just before the threaded section
a bust disk wouldn't hurt as well....

[Daryl]

I hope it works for you. Seems to me according to your diagram, there is too much area (volume) around the transfer port, such that power will be lost plus air waste.

Maybe I am not understanding this system?

[leadslinger]

Why not just put a ASA on the rear? Then you can thread on a tank, with a reg, gauge and a fill probe?

[FarmerDanz]

I hope it works for you. Seems to me according to your diagram, there is too much area (volume) around the transfer port, such that power will be lost plus air waste.

Maybe I am not understanding this system?

It will "work" for sure, but you might be right man. I have no idea at this point how the valve will behave. Its going to be fun for sure figuring it all out. The cool thing is the valve is able to be replaced and its pretty huge so I can try different stuff.

Why not just put a ASA on the rear? Then you can thread on a tank, with a reg, gauge and a fill probe?

Really good idea! No reason not to at all. A regulator would be cool, too. So far I have built about everything, so that has been fun. But the air part I think I will out source. Hehe. I originally planned to make my own air cylinder but its just too sketchy.

[wesb2007]

Cool ideas and work, it'll be great to see how it all ends up in the final configuration [emoji5]

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[leadslinger]

I hope it works for you. Seems to me according to your diagram, there is too much area (volume) around the transfer port, such that power will be lost plus air waste.

Maybe I am not understanding this system?

It will "work" for sure, but you might be right man. I have no idea at this point how the valve will behave. Its going to be fun for sure figuring it all out. The cool thing is the valve is able to be replaced and its pretty huge so I can try different stuff.

Why not just put a ASA on the rear? Then you can thread on a tank, with a reg, gauge and a fill probe?

Really good idea! No reason not to at all. A regulator would be cool, too. So far I have built about everything, so that has been fun. But the air part I think I will out source. Hehe. I originally planned to make my own air cylinder but its just too sketchy.

They do make some high pressure regs. ASA or a tank block would be much more simple. I bought a 13 ci HPA tank that was refurbished for 60$ had a 850 PSI reg on it, fill probe, burst disk and gauge. Then I wanted to run higher pressure and bought a 1200 PSI reg for like 25$.

[Ace]

They do make some high pressure regs. ASA or a tank block would be much more simple. I bought a 13 ci HPA tank that was refurbished for 60$ had a 850 PSI reg on it, fill probe, burst disk and gauge. Then I wanted to run higher pressure and bought a 1200 PSI reg for like 25$.

that would make much more sense....
only thing is how far back will the bottle be after attaching an ASA and leaving the reg on..
i think it should be fine and still be a decent check rest...