Pneumatic Silencer?

[Northir]

i was told today that the cannon i made is to loud and destructive so i thought what if it was quiet and destructive, ive seen a few silencers around but wasnt sure if they would work on a air cannon, what do you guys think?

on a totally different topic, i dont want to glue my barrel to the male coupling so i was thinking of just putting some screws in to it, would that be enough to hold it without breaking

[jackssmirkingrevenge]

Do a search, plenty of silencer info

[Northir]

yea the search here hates me i get 9089 results when i search it most of which have nothing to do with them

[grock]

try advanced search on the homepage, then you can narrow it by forum, keywords you dont want, author etc

[MrCrowley]

I get 58 results searching under the pneumatic cannon discussion section.

[Northir]

i guess that less is more in this search engine "Pneumatic Silencer" gives 1000 under the pneumatic cannon discussion section And "Silencer" gives 58

[MrCrowley]

i guess that less is more in this search engine "Pneumatic Silencer" gives 1000 under the pneumatic cannon discussion section And "Silencer" gives 58

It gives 1000 because it searches pneumatic seperately. Why would you search 'pneumatic' in the pneumatic cannon discussion section? You already know all the topics in there are related to only pneumatics.

Try searching 'pneumatic silencer' in all of the sections but tick the box "Search for all terms".

[Northir]

lol i got it anyways, not finding any real plans or ways to build them, more or less im seeing thats its not a good idea as it can make them illegal, which irritates me because this means i cant use my cannon at all, since like i said my land lord thinks it loud and destructive

[Davidvaini]

its okay, the default search on here sucks.

I think it all depends on what you really want.

For Airsoft Guns, a typical baffle system doesn't really work that well because you are not trying to cool down any gases by letting them expand in a chamber.

Most of the noise comes from the gearbox of the gun, but some does come out the barrel. So I create a suppressor that is designed like this:

and it seems to work out really well. It allows for the noise that does come out the barrel to hit silencing foam and be absorbed.

But for larger cannons with a larger volume of air, I'm sure there is a better way of doing things.

[MrCrowley]

In America, yes I think so. You wont find many plans anyway but more ideas and designs (usually by JSR). There's heaps of topics on this, you just need to find out the principle behind why silencers work so well and go from there.

[Northir]

im almost thinking i could just port the barrel and wrap it in black insulating foam,

EDIT: im thinking ill just scrap the silencer, but any ideas on temporarily attaching a coupler to my barrel?

[jackssmirkingrevenge]

A smaller chamber and longer barrel will cut down significantly on noise. Given the size of your launcher, the volume of silencer needed to adequately reduce noise levels would result in the cannon being somewhat clumsy. Still, a reasonably sized can on the muzzle end will take the edge off the muzzle report and make the noise more "socially acceptable" so to speak.

[Technician1002]

Excess chamber size that results in very high pressure behind the projectile at exit results in a mass of air exiting the barrel under pressure that rapidly expands, much like the air in a balloon when the container is compromised.

A longer barrel or a much smaller chamber operated at higher pressure to provide the same energy to the projectile increases the efficiency and reduces the bang. Look to design one where GGDT warns you "barrel excessively long" and look for a curve where the projectile stops picking up speed before it exits.

This thread covers the discovery of the reduced noise.
http://www.spudfiles.com/forums/failed- ... 17989.html
The resulting launcher was very quiet with reasonable power. Operating at 110 PSI the launches were the most silent. Note the very small chamber and large barrel.

You can hear the launch here. The valve in the tank makes a clank that is louder than the actual launch which is almost silent.
http://www.youtube.com/watch?v=ZUTXomfdLTE

[jackssmirkingrevenge]

Look to design one where GGDT warns you "barrel excessively long" and look for a curve where the projectile stops picking up speed before it exits.

There are of course practical limits to barrel length

Yea, a 10 foot long 12G barrel is kinda long.
Edited by jrrdw.

[Hotwired]

Not much point in silencing a random cannon, ideally you should have designed the cannon with silencing in mind.

High pressure, small chamber, small bore...