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Burst Disc Mortar

Posted: Sun Apr 15, 2007 2:10 pm
by noname
Well, this is just a burst disc cannon, and unfortuneately it's stronger than the barrel sealer 4 times its size.
Chamber: 1 foot of double layered 2" Sch 40
Barrel: 1 foot of 1" SDR 21
Valve: 1" Union
Burst Discs: Scored Playing Cards (thanks fnord)
Detachable/collapsable/multi-angle stand
Extremely compact when disassembled
Ammo is 1/2" end caps filled with BBs or whatever with a screw in the bottom. Drop it down when the gun is pressurized and when the cap gets to the bottom of the barrel, it's blasted out.
Any questions, just ask.

Posted: Sun Apr 15, 2007 2:25 pm
by spudthug
WOW......... that is one nice gun....but how does it go off when u drop the ammo down the barrel??? and one more question are the burst discs in your pic on the left used and on the right unused?? idk but some have holes in them so i was jsut wondering

Posted: Sun Apr 15, 2007 2:27 pm
by Velocity
Yeah its a pneumatic... not a hybrid.

Very nice gun. I have never experimented with burst disks before, because I do not have the type of shooting grounds to use them. Though I'm sure this one has crazy power.

Posted: Sun Apr 15, 2007 2:30 pm
by spudthug
yea i made a mistake and then i realized when i read my message i was like damn i said hybrid...but it was a mistake and i ment to say i have never experimented with burst disks...


althoguh i have yet another question...do burst disk make a cannon more powerful??? because of the gaping hole that is liek just there?? or what..i would guess but im not ocmpletely sure

Posted: Sun Apr 15, 2007 2:37 pm
by Flying_Salt
Hmm playing cards, have you tested what pressure they break at?
Do you have to move your hand away before it gets blown off, or does it slowly slide down the barrel?
Nice paint job, what's the best way to paint camo?

Posted: Sun Apr 15, 2007 2:38 pm
by noname
Spudthug, the ones on the left burst successfully and the ones on the right didn't. It "goes off" because the ammo has a screw in the back of it, so it pokes a hole in the disc, then air rips it apart.
According to the CV listings on the SpudTech forum, a 1" union has twice the flow of a 1" sprinkler.

And yes, this gun does have crazy power. At the angle you see it, it will make a 2" long piece of dowel land about 100 yards away. Shooting an end ap "dart" at a 45 degree angle ends up with the dart about 250 yards away.
It's also loud enough to keep me from hearing anything for about 20 seconds after I shoot , and the blast echoes off the surrounding houses and makes all the dogs bark. I think I'll make another one, paint it black, and hide it in a bush to freak out little kids. :D

Jeez, this is what, the 4th edit?
The easiest way to paint camo is a base coat of the lightest color, or a color that doesn't show up when you paint it over darker colors. This was green in mine. I painted it green and red first, one can in each hand, just spraying randomly with both. When that coat was dry, I did it again. Lastly, I did a coat of black and red, and came out with the current paintjob.
As I was typing this, Flying Salt posted, sooo
They don't burst until I pop them (about 90-120 psi), unless I score lines on them with a nail.

Posted: Sun Apr 15, 2007 3:02 pm
by lukemc
ahh very clever a burst disk that is "popped" instead of broken. from your picture it looks like about half of the disks didnt work why is it that so many failed?

Posted: Sun Apr 15, 2007 3:06 pm
by iPaintball
You inspirational bastart you. I think you conviced me to make one of these! :twisted:

Posted: Sun Apr 15, 2007 4:14 pm
by homedepotpro
ha! i have the same pump

Posted: Sun Apr 15, 2007 4:28 pm
by A-98
very nice, ive wanted to make a mortar, but frankly burts disks scare me. i never know when they are going to fire. i tried solving that with THIS cannon. still scared me tho.

i wanted to build one with the nail trigger idea, but im afraid that i would not be allowed to use it due to the fact that there would be a relatively heavy object with a nails sticking out of it falling from the sky. i may use a solenoid to fire it, but i would need to work out the specs for that first. maybe a piston inside the chamber?...*starts thinking *

the stand has inspired me, i think ill build something like it.

Posted: Sun Apr 15, 2007 6:45 pm
by VH_man
DOes putting a burst disk between a piston valve and a barrel do anything? i know with combustions it has an effect but im thinking it would lessen the opening time variable................ i dunno ill try it

EDIT: i tried it on my AA battery rifle..... hot damn. it works...... a simple peice of cardstock paper works perfectly.... its LOUDDDDDD too........

EDIT2: I forgot to mention the battery went much faster. usually i hear the BAM and then i can say "missisipy" b4 it hits the tree 100 feet away that i shoot at, but with the burst disk its was BAM CRASH with a barely countable time inbewtween. im gonna put one of these on the end of a 2 inch sprkinler valve and make the most powerful sprinkler valve cannon in existence.........

Posted: Sun Apr 15, 2007 6:51 pm
by noname
When I read the first part, I was going to write that it'll be much louder, but evidently you found out on your own. :D
To anyone wondering about the stand:
It's a 1 1/4" T with a 1 1/2" hole in one side. There's a short piece of pipe in the lower socket to make it fit perfectly over the 1" barrel. The sides have 1 1/4" x 1/2" female threaded bushings. The legs are pieces of 1/2" Sch 40 with male threaded street elbows at each end, making it detachable/multi-angle.

Posted: Thu Jun 28, 2007 7:38 pm
by e1337
Very nice cannon, But a question. What is the Ts diameter...

Posted: Sat Jun 30, 2007 7:38 pm
by noname
Read my post, the one that's right above yours.