Page 2 of 2
Posted: Mon Feb 08, 2010 11:22 am
by sgtmik
Spud Bud
know i can get more power out of a pneumatic but the problem is that i don't have a compressor and if i were to buy one portability will be an issue. And I don't think pumping up a dual chambered air cannon with a bike pump will be too efficient...
If you don't have a compressor, buying one will be expansive and actually the cycle time will be just as long if not more long than a propane one. The bigger the tank, the smaller your compressor, the longer it will take you to shoot off a couple shoots.
My final word, go for a combustion. I am tellin' ya. Go for combustion. I have both and I enjoy my combustion for big projectiles and my air riffle for small projectiles. Here's a link to EASILY calculate your ratios and meter length, pressure etc. I found it easy to use and that using it made the construction of my combustion canon A LOT EASIER.
http://www.burntlatke.com/ft_live.html
You should know that the fuel mixture and atmospheric pressure has to stay as it is.
Posted: Mon Feb 08, 2010 1:36 pm
by Spud Bud
Yea i was hoping to break the 900 ft/lb barrier.
Considering i made a dual chambered pneumatic with two 3'' chambers, 24'' long, will it take a vast amount of pumping to get it up to 100PSI? I was researching a bit on the piston valves and i think i would be able to make one but then again the pumping will probably take a very long time and will be tiresome I suppose.
Posted: Mon Feb 08, 2010 2:09 pm
by sgtmik
Im tellin ya dawg. Go for combustion
Posted: Mon Feb 08, 2010 2:25 pm
by Spud Bud
sgtmik wrote:Im tellin ya dawg. Go for combustion
I am going for combustion..how much didn't cost you to make yours?
Posted: Tue Feb 09, 2010 1:03 am
by McCoytheGreater
Hubb wrote:Is there any other reason to go with a combustion?

The only other reason I can think of is against forum rules.
Edited by BTB.It was still too obvious..
Posted: Tue Feb 09, 2010 10:33 am
by sgtmik
[/quote]Spud Bud
I am going for combustion..how much didn't cost you to make yours?
About 100$ actualy. It wasn't too bad. But I added stuff since then so now it cost me about 20$ more. And it includes the 13% taxe i am paying (Fuck the canadian taxes!!). So for a hundre bucks, i think you are go to go. Don't buy a chamber fan yet. Go for the main component. Chamber, barel, propane, propane meter and ignition (BBQ).
Posted: Tue Feb 09, 2010 12:57 pm
by Hubb
sgtmik wrote:Im tellin ya dawg. Go for combustion
That statement is just about sig-worthy...

Posted: Tue Feb 09, 2010 5:43 pm
by sgtmik
God! Can anyone help me doing a good well made quote. I donT understand how they work!
Posted: Tue Feb 09, 2010 7:12 pm
by Spud Bud
Alright then, when i gather up all the components,hopefully under a month

, I will post up some pics of the finished cannon. Thanks
Chamber length estimate is too long
Posted: Tue Mar 09, 2010 3:20 pm
by DR
In your beginning post, you stated:
I was thinking of a 4in chamber, 25in long with either a golf ball, tennis ball, or plain'ol 2in barrel of possibly even all these setups with interchangeable barrels.
With a 25 inch long, 4" SCH40 Chamber - you would need a golf ball barrel that is 197-1/2" long. (almost 16-1/2 feet)...
you would need a tennis ball barrel that is 95.49" long (almost 8 feet)...
you would need a "plain 'ol 2 inch barrel" that is 136 inches long (11' 4")
Surprises me that everyone had overlooked this. This topic was posted what... a month ago? I hope that dude didn't really make his chamber that long.
The most important thing you need to do before building your chamber, is determining what size/length barrel you will slap on it.
The biggest barrel would be the 2-1/2" Tennis Ball barrel. The chamber would only need to be just shy of 19" long, to support (volume-wise @ 0.7:1) a 6 foot long barrel. - Total length: just shy of 8 feet.
So, unless you weigh over 140 pounds soaking wet... that's a huge cannon to handle.
A 4-foot long tennis ball barrel is much easier to handle and the chamber only need be a little over 12-1/2" long.
[/quote]