Looking for a quieter valve/cannon design

[urbanfarm]

I am planning my next projects namely 1/4" and 3/4" barrel devices approx 3' and after experiencing the noise of a 2" barrel piston cannon prototype, I would like something much quieter.

I am thinking if I could mount a spring on the back of the piston that may help, am also trying to muffle the noise with an inner tube over the outlet.

Will a QEV be any quieter?

Perhaps another method?

Burst disc seems a good option although it seems quite fiddly....

Please help this noob

[jackssmirkingrevenge]

The main source of noise in a pneumatic is the muzzle blast, so if you want to deaden noise you're either going to have to make a small chamber relative to your barrel, or invest some time and energy into making a suppressor

[spudkilla]

But Jack, Those are illegal.

[jackssmirkingrevenge]

But Jack, Those are illegal.

If you make it removable and threaded to fit a firearm, yes. If it's just an integral barrel sleeve however I think you're quite safe.

[Sticky_Tape]

Isn't everything? I would say keep the piston valve. QEVs that size are exspencive and a burstdisk will be louder.

[Brian the brain]

okay, I've been giving the same advice all day.
Mod a QEV by drilling a equilising hole and install a soft return spring.

This will enable you to get multiple shots by cutting off flow to the barrel when the pilot ( blowgun?) is closed.

This also means you keep maximum power, but when the ammo leaves the barrel, the QEV gets "sucked" closed, so you dont get unnessesary "afterblast".

Furthermore you could use a long barrel with a silencer at the end and run a line from the blowgun into the silencer as well.
Trust me. your neighbours will hear NOTHING.Only noticable sound is the ammo hitting the target.

[grumpy]

But Jack, Those are illegal.

If you make it removable and threaded to fit a firearm, yes. If it's just an integral barrel sleeve however I think you're quite safe.

they are not illegal but you must have a special permit for it .
In the U.S. , if it can be sawed off the barrel and in any way attached to a firearm you must get a special permit for it.

[ALIHISGREAT]

my copper coax's piston made one hell of a clang, due to the fact i didn't install a bumper LOL so i glued 2 layers off bike tye inner tube onto the piston back to quieten it down.

and i doubt you'll get arrested it you make a permanently attached silencer...?

anyway, seeing as you can use a drinks bottle as a suppressor... i doubt you can get a $200 fine for having a bottle of lemonade in your fridge?