pneumatic ideas

[spudthug]

well lately i have been experimenting with dry ice, coke+mentos, and steam. i know a steam cannon has been done but what about maybe a dry ice and water cannon or a coke and mentos cannon?? like an all metal cannon with a ball valve or even a high pressure burst disk?? someone should experiment...maybe me...has anyone ever thgoguht of this??because dry ice + water, and coke+mentos make huge amounts of pressure...people use bottles as chambers and dry ice+water and coke+mentos can easily blow up bottles...so waht about pouring an amount of water down into a chamber via barrel and the dropping small amount of dry ice in and closing the valve..wait liekj 30 seconds and open the valve...or do the dame with coke and mentoes only substitute water for coke and dry ice for mentoes...


the only thing i would be conserned(sp?) about is the chamber blowing up...know i dont think the pressure generated will blow up metal but ill ask u guys before i try it...btw i am currently out of supplies and the store wont sell me anymore dry ice theyre afraid im doing something with it...hehe and i will pick up some coke and mentoes if u guys think this is possible

[keep_it_real]

I think a burst disk would work really well. In a metal chamber, the burst disk kind of acts like a safety pop off valve. You should put a gauge on it so you know sort of when it's going to shoot.

[spudthug]

yea a guage might be nice but i dont think a ball valve qould be safe...maybe a kind of thing like what noname did but with some kind of dropping mech like a peice of plastic that was seated in a slit in the top of the barrel and pulled by a string from a distance to fire....hmm

[pyromaniac]

put a pressure gauge on a closed off chamder drop some dry ice and water in and see what it generates.

A burst disk would be good drop it in put the disk on and run!

[spudthug]

but the thing is i am building a diferent gun right now...and i would probably have all of the supllies but what i dont have is a union...so i cant do this right now and i am not completely sure how burst discs work in a union exactly...*me runs to the wiki...or clicks...*

[hi]

your unscrew the union and put the burst disk between the two and the screw it back together. i dont think coke and mintoes would to well because it would make the gun and union really sticky. the dry ice, however, is a good idea, but you would need every single part be made of steel. the barrel would be the only thing that could be pvc. you will need (not an option) a pressure gauge, you could be holding a bomb and not even know it if you dont.

[pyromaniac]

If its a mortar you dont need a pressure gauge because you drop it in and run 50 feet.

[jssizzle]

I made a dry ice cannon once, but I don't recommend making one like I did.
The cannon was simple some steel pipe with an endcap, I think about 2.5" dia. To fire it I would fill a water bottle with dry ice and water, and cap it. I would drop that down the pipe and then put in a tennis ball or something else that would form a seal. When the bottle exploded, the pressure would send the ammo flying father than any of my spudguns ever would. Eventually I decided to stop using it considering I had to lug around a cooler full of ice and some water, and also because I would never know exactly when it would fire.

[lukemc]

i thought about dry ice cannons before. the idea never got off the ground due to lack of funding and lack of motivation to get funding. its a fun idea to toy around with and i might explore it in the future.

by the way i like jssizzles idea a few flaws but souonds like fun

[Modderxtrordanare]

Putting dry ice in a steel chamber would be a good idea, but seeing as dry ice is about -110 degrees Farentheit, you should probably insulate the chamber so as to not get your hands stuck to it.

I know what it feels like to get stuck to dry ice. I was stupid enough to lick a piece.

[A-98]

WOW! that is stupid

EDIT: needed to make this post relevant

i think it should work with the burst disk idea, and even a high pressure ball valve. a guage is needed for the ball valve tho

[spudthug]

the only thing about the ball valve and pressure guage idea is if i use coke+mentoes it will get really crappy and sticky...if i used dry ice and water my pressure gauge and maybe my ball valve would freeze...

[pyromaniac]

Thats why ive been saying burst disk mortar no need to a ball valve or pressure gauge only the cannon, fuel, stand , and cover 50 feet away.

[spudthug]

yea..if i can get my hands on some dry ice ill get around to buying a union and some other things...think i should use a pvc union?? just kidding i couldnt use pvc union..id die...-110 degrees and high pressures in plastic dont mix very well...

[hi]

no dont use a pvc union, iron ones are only a few dollars more and well worth it. or brass unions, but those are like $20.