SpudFiles

well i'm new and i am making a spud gun and got a few questions
1 if i used a monta in dew bottle for a combustion chamber where do i spray in the fuel? can i spray the fuel in the nozzel? (or w.e. the pipe at the end iz called)
2 doesn't a explosion with this need to be pressureized? wht makes the pre presure?
3any way to make a slilencer?

4 if i used a combustion chamber and had it closed off. will the pressure stay till i let it go to fire? or is that a disaster waiting to happen?

1. idk
2. the combustion makes the pressure, the expanding burning gas is what creates the pressure
3. REASERCH!! (and i know u didnt or u would know they are illegal)

The gases from the combustin will cool and you will lose the presure after about one second.

iamhewalrus i know they are illegal idc reallly
and srry bought 3rd question someone explained a lil weird b4 when i tryed to mkae one it was for engines that the piston presurizes befor the explosion. well w.e. but 1rst question i need an anwser.

1: Typicaly, if I understood the question correctly, through the normal opening they made at the factory.

2: Typicaly, especialy for a gun using a bottle as the chamber, the fuel-air mix is prepared at atmospheric pressure. That is, before firing, the chamber has the same internal pressure as outside.

3: I reccomend that you don't. They are of dubious legality in the US, which due to the lack of information given in your profile, is where I assume you are.
Furthermore, there are simpler means of making the gun quiet; namely making the barrel longer - a .8:1 (C:B volume) ratio is probably good enough for your aplications, and a .6:1 should be low enough for anyone. This long of a barrel has the advantage of maximizing velocity from a given chamber size.
If you do make one (which I'm not going to help you with), it is more likely to comply with US laws if you attach it permenatly to the barrel.

uhh thats nice and all but i don't think u got the last question...but nvm that idc

for the first one really where do u spray in the fuel for the combustion gun?

heres a description of wht a gun i know is. so do u spray fuel in the tube or in the cape? wouldn't a pop bottle be hard to cut there?

http://img473.imageshack.us/img473/2049/000000003yt.png

any 1 there? please anser lol

ok, im jsut going to make a suggestion, that u dont make ur first combustion with a coke bottle, jsut make a chamber out of PVC, a lot easier for someone of ur spudgun knowledge. that way u can make a chamber that already has the 2 holes in it for the barrel and the fuel.

hmk then well mind if i ask u a few questions on aim?

aim- zeig1

go ahead and message me anytime, im almost always on.

AIM= iamthwalrus3 (note there is no E in 'the' in my screen name)

Spraying the fuel in the bottle will be easy, but the venting will be a bigger problem.If you don't put the ignition in the senter, the fuel will burn too slow and the canon will suck in general.

why are like 3 of the posts gone? lol

Gust buy some pvc and save yourself the hassel.