Anything wrong with a 2" chamber?

[Binder17]

I have designed a spudgun that has a 2" X 6" chamber and .75" X 48" barrel. I will use metered fuel and fire with a bbq sparker. I not going to bother putting a fan in it. Is this worth building and will it shoot?

[hi]

i have a cannon with a 2x18'' chamber and a 3' barrel, it gets about 250 feet with a tater.

te one you designed has a barrel that is way to big, you need the barrel to be no more than about 15 inches.

[Binder17]

So don't worry about the ratio?

[rednecktatertosser]

i have a cannon with a 2x18'' chamber and a 3' barrel, it gets about 250 feet with a tater.

te one you designed has a barrel that is way to big, you need the barrel to be no more than about 15 inches.

Hi you know his barrel is 3/4" not 1-1/2" right? cause a 15"x3/4" barrel would be about right.

@Binder- you should really consider a fan, they really boost performance, but in the end its up to you.

[hi]

no, what i mean is that i made a cannon with a 1.5'' barrel. it has nothing to do with his.

i know that 15 inches is about right because thats what i said, reread my post redneck.....

edit- yes worry about the ratios, a chamber that is 2'' diameter and 6'' long needs a 3/4'' barrel that is about 15 inches long.

if it was 48'' it wouldn't leave the barrel.

[rednecktatertosser]

OOPs i thougt the original post said 2'x6" nevermind, your right.

[psycix]

why wouldnt it leave the barrel with 48"?
The ratio is about 0,95 then, on 15" the ratio would be like 3.
And hey, if the barrel is too long, just take some off
U can always make it shorter.

(btw Chamber fan will boost performance alot + luxury of vending chamber)

[WOW!!]

I made one that is 2''x6'' with a 1'' barrel. It works really good. Shoots 175+ feet. Single electrodes and a BBQ ignitor. Nothing fancy just something to use around the shop and for the little kids to use.

[Binder17]

I'm just going to put some pennies in the chamber to shake around and mix the fuel and air. It is not worth wiring a fan in it.

[psycix]

That will do too.

Just wondering to be sure:
Do pennies spark?

[hi]

pennies would probaably spark, they are mostly copper.

I made one that is 2''x6'' with a 1'' barrel. It works really good. Shoots 175+ feet.

are you sure do dont mean 1'?

anyway, a 2x6'' chamber cant provide enough power for a 48'' barrel, its just to big. even wth oxygen and mapp gas (dont even think about trying it) it wouldnt be enough.

you need a 15 to 18 inch barrel tops, no more than that. it simply wont work. try it and see.

[Jumpin Jehosaphat]

Using sch 40 PVC the ID of a 2" pipe is 2.049, so the volume of 6" of that would be about 19.784 cubic inches. The ID of 3/4" PVC is 0.810" so the volume of 48" of that would be about 24.734 cubic inches.
The C:B ratio of the cannon described in the first post would be 0.7999:1
The dimensions given in the first post are perfect! You could stand to make the barrel an inch or two longer, but I wouldn't.
Hi, I agree it doesn't seem like this should work, but the barrel is less than half the diameter of the chamber he is using, this makes a huge difference when calculating the volumes.

[Binder17]

So the .8:1 ratio I used is right and the specs I came out with are right?

[noname]

I knew something was missing...

[Binder17]

Volume is pi*r^2*l

His math was perfect. Double check your formulas.