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first combustion cannon

Posted: Sat Oct 22, 2005 5:59 pm
by smoch125
i made this a while ago..but didnt have a camera to take pics. combustion chamber is like 12in of 3 in pvc and barrel is 4 ft of 1 1/2. i just use a lantern lighter to ignite and static guard for fuel (i use static guard for my mini as well) it works great.

Posted: Sat Oct 22, 2005 10:18 pm
by Shandora
that to me llooks like 2ft of 4 inch chamber and 4 foot section of 2 inch pipe 8)

Posted: Sun Oct 23, 2005 1:42 am
by Ballad_Black
I dunno, looks like a foot of chamber to me, and it also looks like 3 inch pipe. Anyway, thats how my first gun looked, but I painted it florescent orange. Still don't know why I did that.

Posted: Sun Oct 23, 2005 3:11 pm
by smoch125
no... it's a 3 in chamber 12 or 13 inches long and the barrel is sdr 21 (1 1/2 in) trust me i made it. lol :wink:

Posted: Sun Oct 23, 2005 5:36 pm
by Ballad_Black
Yea, I figured you just had a typo on the chamber. But i did believe the barrel ,lol.

Posted: Sun Oct 23, 2005 5:40 pm
by spudshot
sleeve that barrel, SDR 21 is very brittle and can break easily when in a long length, get some 2" sch 80 PVC and push it over the SDR-21

Posted: Thu Oct 27, 2005 7:01 pm
by smoch125
well, it has a 200psi pressure rating, but also thin walls? is this why i should sleeve it? because the 200psi should hold true.

Posted: Thu Oct 27, 2005 9:08 pm
by CS
I dont think that youll have to worry about the pressure created inside in the barrel but since it is so thin you do have to worry about it bending. Some of my early combustions have GB barrels but there not sleeved and they all have started to bend. If you figure out which way it is curving it actually works out good for a hop up device. In case you dont know what a hop up device is, it makes a back spin on the ball and if shoot right the ball will seem to "float" instead of just dropping of when the ball loses it intial velocity (IV might not be the right term but you get what I talking about).