SpudFiles

well the thing is pretty much a Pneumatic bomb launched or thrown and detonated on impact for blasting flour, paint, and posibely bbs for senerio games

the idea is simple and cheap on impact the nail will pirce the burst disk causing air from the bottle to blast flour paint or bbs out the holes, the hole can be covered with something light such as toilet paper or saran wrap

I'm still testing it I need some more schraders to do it but I'm trying it while standing on a 3liter bottle and maybe latter I will try using viniger and baking soda before I can finally get more schraders

did that make sense I kinda tired so I might be ranting right now

I don't quite understand it. want throwing it, then you have to make it land on the nail side, if you want to push the nail into the cap, then it will blow in your hand. BTW, cool design, but needs some tinkering. Good luck with testing it.

Looks ok to me, but i'm no expert, the only thing i would change is to make it bigger or go for high pressures.
It would be sick if you had lots of them in a paintball game.

Edit: Maybe you could use baking soda and vinegar as a "fuse" that way you could cook it before you threw it.

yea but would somebody explain to me how would you set it off? Plus wouldn't you have to put a lot of pressure on the nail to go through the cap?

The only way i see it is shooting it from something

it screws onto the the tip of a bottle and you throw or launch the bottle during impact the nail pireces the burst disk relaing the presure, I have the prototype in front of me only if I had my camera

its basicly a burst disk. when the nail hits the ground it pops the soda cap and releases the air.

the problem is that the only way it will work is if it lands on that side. if it dosnt it wont go off.

the only think i can think of is make the "trigger" part really really heavy that way it lands on that side when you throw it, but you would really have to arch it for it to work.

its looks cheap to make, so i say try it.

i agree with hi, but weight to shift over it would have to be a throw of at least 15 feet.

hi wrote:its basicly a burst disk. when the nail hits the ground it pops the soda cap and releases the air.

the problem is that the only way it will work is if it lands on that side. if it dosnt it wont go off.

the only think i can think of is make the "trigger" part really really heavy that way it lands on that side when you throw it, but you would really have to arch it for it to work.

its looks cheap to make, so i say try it.

yah I know ways to make bottles fly straigt, and the presure for the nail isn't so bad especally when it is closer to the activation presure

Heres a idea I just thought of

make it with a union and have a chamber filled with dry ice and water that when thrown the dry ice would hit the water and create enough pressure to blow?
It would work, all you would need is a system that would only allow the 2 to be mixed after being thrown.
Maybe a ball valve?

What happens when the nail part flies off and hits someone?
Its a good concept but why not make them to be launched out of a specialised canon? Or if you want to be throwing them why not get two end caps, flare one so its pretty tight. Fill it with paint or what ever and have a screw in one end of a cap and soda bottle inline with it in the other cap, put the two halves together and hit then on the ground to puncture it and fire in the hole

You would have to fiddle with it to make sure it doesn't pop in your hands and this way there wont be a nail flying off and the halves could then be reused Just a thought, let us all know what you end up doing mate.

You're going to have to work on your "fuse", if you build it as it is it will burst in the barrel as soon as you fire it.

frankrede wrote:Heres a idea I just thought of

make it with a union and have a chamber filled with dry ice and water that when thrown the dry ice would hit the water and create enough pressure to blow?
It would work, all you would need is a system that would only allow the 2 to be mixed after being thrown.
Maybe a ball valve?

good idea frankrede, I used to do those bad vinger and baking soda bombs and they are not a allowed acording to forum rules, but one of the triggering methodeds I learend, probebly shouldn't use dry ice since it melts fast even without water

mtronic wrote:What happens when the nail part flies off and hits someone?
Its a good concept but why not make them to be launched out of a specialised canon? Or if you want to be throwing them why not get two end caps, flare one so its pretty tight. Fill it with paint or what ever and have a screw in one end of a cap and soda bottle inline with it in the other cap, put the two halves together and hit then on the ground to puncture it and fire in the hole

You would have to fiddle with it to make sure it doesn't pop in your hands and this way there wont be a nail flying off and the halves could then be reused Just a thought, let us all know what you end up doing mate.

well the diameter of the nail is really small and the force of the impact is still holding it down... how do I explain the who diameter thing well the presure is apllied on a very small area so there is little force, its like trying to launch a juice pouch by blowing on the straw its really hard because the area of the straw is so small

anyways if you don't understand or don't agree I also have a dot of hot glue on the nail

@jack: good point I will work on that

good point I will work on that

All you have to do is turn it upside down (ie load it with the cap end facing the breech) and make sure the nail has a stop to prevent it from falling out on firing.

You really shouldn't have to fiddle with this design much to make it aerodynamically stable.

The payload presumably has some mass. Probably more mass than the soda bottle. The bottle will act as a fin, the payload is fairly small, massive and in the nose.

Shouldn't be any problem getting it to fly payload first.

If the payload is small enough it is pretty easy to tell if it'll be stable in flight.

Find the front to back center of the loaded projectile.

Balance the projectile on a sharp edge and find the front to back center of mass.

If the center of mass is at least 1 bottle diameter in front of the front to back center of the bottle you have a good chance it'll be stable. The more you shift the center of mass towards the front the more stable it'll be.

If the mass is insufficient, or the bottle too short, just add streamers.