11 replies to this topic

[Matt31]

I whipped this up just now in about 20 min. Not nearly as impressive as the football with the mousetraps inside but easily mass producible and cheap. The concept is a heavy ball on the bottom, connected to a rod that has a little platform and a stopper on top. PVC is around the platform and the stopper, and filled with little 1" darts. The platform keeps the darts from falling out the bottom and the stopper keeps them from flying out the top. When thrown the ball comes down first and the PVC slides down the rod, thus releasing about 15-20 1" darts in a "blast" radius of about 10-15'. These numbers could be improved greatly with advancing models of the same concept.

[Green-Buckshot]

Interesting prototype. All these recent grenade attempts are giving me the itch to try it.

[dooda]

What is with all these grenades people. You should just stick to the fold up frizbee it's so simple.

[Bomberman]

What is with all these grenades people. You should just stick to the fold up frizbee it's so simple.

People are trying to get better results than the foldable frisbees, and something cheaper. And, something that could be more practical, and that anyone can make. I think that this is a very interesting prototype. I just wish I had the materials to make it. But I'm broke until June.

[eddieoctane]

Interesting. So if I understand right, this operates similarly to a manually operated plunger, but the ground forces the piston through the PVC instead of your hand. Simple enough. Still, this could be dangerous. The end of the plunger needs to be heavier than the PVC shell to ensure that the right end falls first. The shell needs to be heavy enough to force itself down when the thing hits the ground. The whole grenade might end up weighing enough to hurt someone when it's thrown. Props for coming up with something functional, but I think a folded frisbee is less likely to cause a lawsuit.

[Matt31]

Well, this was my best attempt because I can not find foldable frisbees anywhere! But after some testing, and physics class I remembered that it doesn't matter how much something weighs when it falls. The ball doesn't necessarily fall first, rendering the weapon pretty useless.

[eddieoctane]

Well, this was my best attempt because I can not find foldable frisbees anywhere! But after some testing, and physics class I remembered that it doesn't matter how much something weighs when it falls. The ball doesn't necessarily fall first, rendering the weapon pretty useless.

Well, you are right and wrong on that. In an ideal setting, all objects accelerate at the same rate due to gravity. However, reality is not ideal. Air resistance lets a bowling ball fall faster than a feather. But what I meant was that the thing needs to be properly balanced. Too much weight on the wrong end can cause it to change orientation, and the wrong end can hit the ground. Aerodynamics can also cause this effect.

Also, kinetic energy is dependent on mass. All surfaces in contact experience friction. When the grenade hits the ground properly, the kinetic energy of the cylinder part needs to be able to overcome the friction the moving parts of the grenade experience. Otherwise, even if the device impacts properly, the upper cylinder won't move and the whole things is effectively a rock thrown at someone you were playing a game with..

[foo fighter]

Do you think you could post a video test-fire? And what size pvc did you use? I'm going to attempt this..

[Matt31]

I'll see what I can do towards a video, 2" PVC to answer your question.

EDIT: kinda dark but:

Edited by Matt31, 18 May 2008 - 11:18 AM.

[AlaskaRecon]

The video didnt look that impressive but unless the grenade is powered by an explosion it will never be that amazing. I think that you should make it so that in midflight it will fire the whole ball and stopper construction out of the top raining foam opon the enemies heads. I suck at that kind of thing but I think it would be preatty effective if someone knows how to do that without so much weight that it kills someone.

[nerferfan]

Sweet!
thats the best thing ive seen in ages!!!
I'm hopefully gonna make a 'mortar' with a titan & stuff, and i can use this as a kind of ammo, or moddify it to shoot off a titan but instead of the ball pushing the balls out, rig string so you shoot it into the air, the string pulls it, and drops the darts. no one will know what hit them.

[CaptainSlug]

Sweet!
thats the best thing ive seen in ages!!!
I'm hopefully gonna make a 'mortar' with a titan & stuff, and i can use this as a kind of ammo, or moddify it to shoot off a titan but instead of the ball pushing the balls out, rig string so you shoot it into the air, the string pulls it, and drops the darts. no one will know what hit them.

Goodbye for 30 days

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