Hammer Valve Vs Piston?

[us sniper]

Are you going for multiple shots or mainly for power. You don't have to use a scuba tank you can just use the 88 gram co2 cartriges for portibilty. After you are done please post your gun, I have been wanting to build my own bb gun too. I just find this on the web, it is an option if you decide to turn away from co2: http://images.google.com/imgres?imgurl= ... soft:en-US

[jackssmirkingrevenge]

us sniper, there is NO WAY a home-made springer is going to compete with the pneumatic being contemplated here.

Chaos, your GGDT model looks good. You could cut down the pilot volume to 2cm but I don't know how you plan on building it exactly so I'll give you the benefit of the doubt

[Modderxtrordanare]

You're welcome for modeling it a few times for you.

I do apologize for hi-jacking the thread though.



But, by brass seals, I believe at such high pressures (2k psi you said?) it would press the brass into the barrel's sealing face enough to seal. Rubber would just get cut like a cookie cutter. Just my idea of why, it could be right or wrong. Someone should clarify, as I would like to know as well.

[chaos]

ok thanks ModderX,

hmm brass aye, what about nylon? i do agree the rubber may fail at those pressures.

Jack when i cut the pilot volume down any further on ggdt, it comes up with errors and sh!t.

n yer us sniper springers are no match for PCP's

im actually worried about safety for the first time on this one

[Modderxtrordanare]

ok thanks ModderX,

im actually worried about safety for the first time on this one

Maybe its a sign?*

What does PCP mean anyways, aside from the drug.



*To do it anyways.

[VH_man]

yes, brass seals are when you use brass, a soft metal, and seriously smooth it. look in the hardware section, and find a large brass swing-check valve. youll find an example right there.

bascially, yes, no more rubber. it will be hard to make it work, but if it does............................

honestly, id just go for a wide rubber sealing face along the ouside of the barrel that the piston, faceless, pushes against. BTB also did that on his sawed-off, before he used the brass seals.

[chaos]

oh k kool thnx VH Man that makes a bit more sense to me now..

ModderX: PCP stands for Pre-Charged Pneumatic

i think if i found the right way of attaching the rubber sealing face and also found the right type of rubber it may work.

we will see im still thinking bout this one

[us sniper]

Are you trying to make someting like the talon? Also what fps are you expecting from this gun. Since you can machine parts I would go with the hammer valve since they are consistent. To solve the problem of the shots getting less powerful you could have a smaller bottle of co2 that acts as a chamber. That way the pressure can be kept high but the scuba tank regulates air to the smaller tank. That way the chamber is always at the same psi when the co2 is released. Aslo, the hammer valve is what is used on the nelson gun or am I mistaken if so please correct me.

[chaos]

@us sniper, sorry but hammer valve aren't that great power wise, and power & accuracy are what i am aiming for here.

have a read through the previous pages if you haven't already and you will see that we have discussed hammer vs piston valves already and i have made my decision already to make a piston.