CBHV: Masterclass entry

[jackssmirkingrevenge]

Get the machinery

I already has it

Added to that as a birthday present I'll be getting myself a dedicated table and motor for the mill, so I don't have to disassemble it every time and give me a bigger working range, plus probably some other little gadgets...

So yeah, no excuses

[Brian the brain]

I could really use a mill...
But I'll have to get it done with a lathe, welder, various taps and dies, powerdrill handtools etc...poor me

I'll go and weld on the "T" transfer port up on the main tube tonight if I get a chance.

Wifey's pretty sick a.t.m. so I might be up all night tending to her and spudding will have to wait.

Oh..I wanted to get an idea of the power...so I put a marble on top of the port and tapped the valvestem.
The marble hit the ceiling.
Is that a good sign?
Not sure, at least I know it can propell something

[warhead052]

BTB, This is going to the competition right?

[Brian the brain]

It's my entry for the challenge, yes.

[MRR]

Looks pretty awesome so far 8) .

Is that a lever from a window opening mechanism?

[Brian the brain]

Yes.
German brand..
We sell them at work and it ended up in the bin more than a year ago.
I had recognised it's potential and kept it.

My 16 mm version pump used the same thing.

Seeing how it works well and looks the part...I don't think I was wrong using it.
The current lever handle will be covered by a wooden one.

[warhead052]

I just had a idea, since you are going to add a wooden handle to it, why not make it a dragunov SVD pcp? That would be insanely cool, and sleek. Not to mention the power from the barrel length.

[Brian the brain]

why not make it a dragunov SVD pcp?

Because I know what I like..

Welded on the barrel mount thingy.I seriously need to fill up those trenches with weld and grind it to a mirror finish...but unfortunately I don't have the time today.

I did get to test it with a 6mm I.D. barrel and it breaks up bb's like nothing...
I do get the feeling that anything over 10 mm I.D. will not do any good.

we'll see....

[jackssmirkingrevenge]

I did get to test it with a 6mm I.D. barrel and it breaks up bb's like nothing...
I do get the feeling that anything over 10 mm I.D. will not do any good.

Big bore or bust, you want at least 50 cal to take advantage of that valve!

[wyz2285]

This may sounds stupid, I was think about your valve and it looks like a "hammer" actuate quick dump valve so when the hammer open it won´t the piston "dump" and stay open until all the air is gone?
If not I really need to try to build this valve

[LovableAirGuns]

WOW that's coming out really well.
maybe i should do a build log like yours but on mine.
looking forward to more of your build good job man

[Brian the brain]

so when the hammer open it won´t the piston "dump" and stay open until all the air is gone?

I had the same concern when I built it's predesessor.

It is somewhere in the middle of a QDV and a traditional hammervalve.
There is some surface for the pressure to work on, although it's tiny.
Both sides are almost equal.

I can tap the valvestem and it closes immediately afterwards.In that sense it feels just like a regular hammervalve.
I just don't have to hammer it like a madman,..while it has better flow.


So a tapvalve would be a better name for it.

[wyz2285]

Any chance of take a look at the valve stem? and does that bulletcap do anything or just for the look?

[Brian the brain]

I'll make a picture for you guys tomorrow.

The bulletnose is the airtight cilinder for the counterpiston.
It's hollowed out.
One end had to be blocked off to ensure the low pressure area in front of the piston.
The shape of that side is rounded off to help air flow around it.
That's how I ended up with the bulletnose.

I just tried it with an 11 mm I.D. barrel.
A thick nail and caulktube-tip cut to size served as a dart.

It was pretty cool...
At 40 pumps the nail went into solid hardwood from the side ( top of the grain is easier) 20 mm.....I have tried a commercial airgun on that block ( from wich Old Shatterhands' stock was cut) and.177 cal balls made just a dent and popped back out.

The coolest thing is:Absolutely no sound apart from the " dook" of the nail cutting into the wood.

I don't really like loud noises...so this is a plus.
Now I can shoot it anytime!
Although a large boom would have re-assured me the valve was doing what it is supposed to...

[wyz2285]

The bulletnose is the airtight cilinder for the counterpiston.

I found out that from the beginning

One end had to be blocked off to ensure the low pressure area in front of the piston.

same as that I thought too, but wasn´t sure so thx

The shape of that side is rounded off to help air flow around it.

Nice thought didn´t think about that.
So the area of the counterpiston is smaller than the seal surface right?