Emergencies. They never advice. They catch you unprepared. And sometimes in some emergencies, we think "It would be good if someone had a gun like Batman's".
This project is for helping people in rescues: a home-made line gun capable of launching a flotable projectile to a man having problems in the water (Right now, In Colombia we have an winter emergency with storms, floods and avalanches, so I think this could be an useful idea for helping rescuers in his job). It could be useful to pass a line from one side to another, too. Or for grab the nearest tree or structure.
How it works? Like the weapon of an action figure. You insert the projectile, the spring compress, and the back part of the projectile gets caught in the trigger. When you press the trigger, the back part is released and the projectile is launched.
NOTE: because the position of the camera (and my bad aim), it looks like a short distance. But the steel cable is 9 meters (30 ft) long, enough for catch a tree branch if you are dragged by a river. (The next week I will do the experiment with a longest cable)
Without the steel cable, the projectile can fly about 20 meters (66 ft).
And why a spring? It's "easy" to recharge and you can do it over and over and over again. Air power could work, but if you want to recharge it, try to find an air compressor in a disaster area or in the middle of the forest. Gunpowder is another option, but imagine you are dragged by a river (powder and water are a bad combination) or inside of a burning building (powder and fire are a good combination, but very inconvenient, too).
This instructable is not the whole idea, but a concept. It's just the begining. Instructables.com is the home of the smartest minds of the world, and it would be great if this become an open project. Somebody carry on making a better spring launcher, and then another one improves the line system, and a third one implement a more resistant cord, and so on. Who knows? maybe one day every one of us could have a grappling gun in his emergency kit. Watch out, Batman!
Step 1: Disclaimers, Cautions and (because We Never Pay Enough Attention to the Warnings), Materials and Tools
CAUTION: Because of the short time of the contest, this is a non tested prototype made of ordinary stuff. Instructables and M.C. Langer are not responsibles for injuries, death or property damage due to the bad, wrong or reckless use of this instructable. Make this project under your own risk. Don't use it in a real or simulated danger situation. Don't aim or shoot the gun against people or animals. Don't try to imitate movies, TV shows or comics actions like balancing your own weight, stop freefalls or fight criminals. Always use personal protection when you work with springs. In emergency situations, always call the competent authorities (911 in US and 123 in Colombia).
Hard spring (impeller)
Small spring (for the trigger)
1 1/2" PVC Pipe (big enough for covering the hard spring)
Garden hose pistol
Three 90° iron angles
Nuts and bolts
Empty yarn cone
Plastic bottle (It will be the head. I use one from a deodorant)
Aluminum cylinder (I use one from a discharged military flare)
1/2" PVC pipe and cap (Note: it will be great if this is replaced with aluminum pipe, or another light metal)
Thin steel cable.
Cord: I use thin steel cable. Paracord could be useful. I know in US you can find a better and lighter cord.
Tools and others:
Dremel rotary tool
And remember the rules:
1. If you don't have it, replace it!
2. Use protective equipment (dust mask and goggles)
3. Beware of drilled and soldered hot surfaces
4. Work in a good ventilated area.
5. Always have junk in stock