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!
Remove these ads by
Signing UpStep 1: Disclaimers, cautions and (because we never pay enough attention to the warnings), materials and tools
Materials:
Gun:
- SUGRU (orange)
- Hard spring (impeller)
- Small spring (for the trigger)
- 1 1/2" PVC Pipe (big enough for covering the hard spring)
- PVC Cap
- 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
- screwdrivers
- pliers
- paint
- superglue
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
6. Enjoy!












































Visit Our Store »
Go Pro Today »




The 3/8" steel cable is only rated to support 30 lbs. while the para cord is rated for 550 lbs.
People often make this mistake, thinking the steel would stronger.
I use the thin steel cable for supporting a bear bag when I'm in an area where I've been told I have to worry about rodents (or occasionally bag smart bears) chewing through the supporting cord. Other than that I don't use it for much of anything.
This being said, I am a fan of the concept and will most likely make my own version in the distant future (with some sort of soft projectile).
in a tense, emergency situation, throwing accuracy can be very bad, and you might not have a second chance. the antennae throwing devices in those video's are bulky, complicated, and expensive. great for antennae's, poor for a flood or overboard victim. you are aiming for something a person can make, easily accessible and inexpensive. super! i'll have to think about this one some more.
And you're absolutely right. About all.
Kudos, someone might make one and save a life
Steve
of a slingshot and put a small weight on the end of the line. For me, its primary function is shooting the line over trees and then pulling antenna wire back for HAM Radio use; Works like a champ. I always use the slingshots that have surgical tubing for the kinetic energy... While it's only good for 50-75 yards, it is consistently accurate. I use fifty pound mono-filament line.
rnc
In fact I can and do use a 3 lb fishing weight tied to 20lb fishing line and can throw it from one end of your yard to the other.
The key is you throw over them not at them; they grab the line and then pull over the rope..
Just a few ideas... Though awesome build and I will have to have a go at one soon with a few alterations...