Thread: A C02 mortar I built in my backyard

Tell me what you think. How do you think it could be improved?

http://www.youtube.com/watch?v=rn8p9ICNZgY

how do you mean improved?

from the video and description i couldn't gather too much about the design. i'm assuming because you described it as a mortar that the nail at the bottom would break the seal on the tank and send it flying. what i would recommend is completely sealing the back end, rifle the barrel, expand the barrel to be slightly longer and wider.

the speed on your projectile isn't enough for rifling of metal on metal to work out too well, you'll loose a lot of kinetic energy that way. i would suggest enclosing your cartridge with sytrofoam fitted to the mortar's radius. just add a little grease to the mortar and it should go down easily and the carbon dioxide should build up to enough pressure that it pushes the whole styrofoam system out much more quickly than before. also, the styrofoam should be cut down the middle so that when it ejects from the mortar it will let your cartridge go on its own. essentially its only purpose is to seal the sides so that pressure can build up, and to be a soft material for the rifling so that your co2 cartridge will spin.

these improvements will aid in the range and accuracy of the device. from your video i noticed your safety precautions were sub-par, experiments in which you say "that almost killed us" are often the most fun, but i would recommend hard hats and some blast glass just in case.

Originally Posted by saul

how do you mean improved?

from the video and description i couldn't gather too much about the design. i'm assuming because you described it as a mortar that the nail at the bottom would break the seal on the tank and send it flying. what i would recommend is completely sealing the back end, rifle the barrel, expand the barrel to be slightly longer and wider.

the speed on your projectile isn't enough for rifling of metal on metal to work out too well, you'll loose a lot of kinetic energy that way. i would suggest enclosing your cartridge with sytrofoam fitted to the mortar's radius. just add a little grease to the mortar and it should go down easily and the carbon dioxide should build up to enough pressure that it pushes the whole styrofoam system out much more quickly than before. also, the styrofoam should be cut down the middle so that when it ejects from the mortar it will let your cartridge go on its own. essentially its only purpose is to seal the sides so that pressure can build up, and to be a soft material for the rifling so that your co2 cartridge will spin.

these improvements will aid in the range and accuracy of the device. from your video i noticed your safety precautions were sub-par, experiments in which you say "that almost killed us" are often the most fun, but i would recommend hard hats and some blast glass just in case.

Thank you

sweet