Picture of The Mini Emergency Line Gun Project
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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!

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skulljo5 months ago
Can it rewind itself
laffinm1 year ago
You should make a shooting video
rncbme4 years ago
I've used something similar for years. I zip-tied a spinning reel to the underside
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.


hey what is your call sign mine is KG5AOD

M.C. Langer (author)  rncbme4 years ago
I have fity pound nylon monofilament. But a very thin line has a problem: could cut easier the rescuer hands. I want to use the monofilamente for a speargun like the one in Batman Returns.
Advar2 years ago
Simply awsome. Nice job! :)
M.C. Langer (author)  Advar2 years ago
Thanks Advar!
MU5ICI4N2 years ago
Amazing! What a sleek, wonderful creation. It would be interesting to have an adaptable projectile with different heads that could click in, such as a grappling hook, buoy, foam-tipped, or one with a little compartment (for getting emergancy supplies to hard- to reach areas).
M.C. Langer (author)  MU5ICI4N2 years ago
Thanks a lot MU5ICI4N!! :-)
fretted2 years ago
Use Para-cord and a monkey fist ?
Wyattr551233 years ago
try heavy fishing line, not steel
HBDWMA4 years ago
heavy line would mean a bit less distance tho, of course.
HBDWMA4 years ago
Just a thought: You can duct tape a fishing reel to the front of a slingshot (wrist-rocket type, not the "Big Y" tree branch type) and launch lines 100 yds.
rimpest4 years ago
Eres Español o que?
M.C. Langer (author)  rimpest4 years ago
Soy Colombiano! De Bogotá! :-)
jmonty4 years ago
i gotta say M.C. Langer, this is a pretty sweet idea! probably will save a few lives dude!
M.C. Langer (author)  jmonty4 years ago
Thanks Jmonty!! :-)
gbearpdm4 years ago
I can iamgine this with a spray propellent/ignition system like they use on potato guns, but I'm not smart enough to design it.
may i reccomend 550 paracord in place of steel cable
Foaly74 years ago
Is airplane wire too thick for this?
M.C. Langer (author)  Foaly74 years ago
I guess.
MaClay4 years ago
Nice piece of engineering and application of reusable and repurposed materials. And in the vein of your request for comments from the instructable community, may I suggest the use of an eye splice in your cable instead of the much heavier cable clamps. A splice although not legally rated for supporting a load, it was used for a long time before compression sleeves and the like were developed. Also the eye splice being lighter would increase range and be less likely to snag on itself or other things (Batman's cape). You could put a copper sleeve over the barbed ends and solder in place, so you wouldn't have to get it perfect on the first try. Plenty of www info to help you do it. A lighter synthetic line would be best, but you are using what you have access to.  Once again, well done, and keep up the good work
M.C. Langer (author)  MaClay4 years ago
Thank you very much MaClay!!! It's a great suggestion!! :-)
billhorvath4 years ago
This is impressive, and smart! As a former wilderness EMT, I can think of any number of uses for this, both rescue-related and otherwise (E.g., it'd make for an easy way to hang a bear bag.) Great work!
M.C. Langer (author)  billhorvath4 years ago
Thank you Doxsys!!!! :-)
RayKenn4 years ago
Excellent work! With a little "polishing" I could see a definite market for this in a variety of areas.
M.C. Langer (author)  RayKenn4 years ago
Thanks Raykenn!!!
dropkick4 years ago
Parachute cord (sometimes called 550 or para cord) would be much lighter, would fly further, and most importantly is rated for supporting much greater weights than the thin steel aircraft cable.

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.
M.C. Langer (author)  dropkick4 years ago
Thanks for the advice. I will make some experiments with paracord.
mathieulj4 years ago
Very nice idea indeed, although i must caution those who think this is ready for the prime time. In this form, you are still firing a metal projectile. NEVER, EVER fire it at/towards someone as you could make the situation worse(by ex. hitting them over the head). If you are in a situation with dire need and have only this first version to help, fire it ether way over the person (the line will drop to them with less of a thud than the aluminium projectile), or in front of them so the current brings the to the line.

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).
M.C. Langer (author)  mathieulj4 years ago
Thanks Mathieulj. You have a point: if you don't use this concept properly, you could be killing someone instead of saving him.
Thaikarl4 years ago
this is wonderful. an inspiring start. i'm a sailor, and i have thought about something like this for an overboard person. i'm imagining a similar device, that was all built inside a PVC tube. the tube would have a looped strap on the bottom end for a grab handle. the pvc would have a inner and outer, slip fit tube. to cock the mechanism, you would slide the outer tube to the strap end, engaging a simple trigger latch that would pop out of the side of the tube when it was engaged. press the trigger and the weighted, projectile would shoot out the end of the tube. in an open water situation, you would have a conflict between weight of projectile - so it would fly, and lightness- so it would float where a person could grab it.

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.
M.C. Langer (author)  Thaikarl4 years ago
Thanks Thaikarl!!!! Well, I was from the Colombian Navy!! :-)

And you're absolutely right. About all.
You know, I look at your line launcher, and I think of all those porr folks who drowned off Christmas island yesterday who might have been saved if there had been a way to get lines to them.

Kudos, someone might make one and save a life

M.C. Langer (author)  steveastrouk4 years ago
Thanks Steve!! And that's the idea. I don't want to see this like MY project, but OUR project. Making a good Line Gun between all could save a lot of lives!
greaserjoe4 years ago
what if you added a CO2 can and instead of the yellow rocket,you add a fiber glass hook??
M.C. Langer (author)  greaserjoe4 years ago
Could be!
replace the spring launcher with a pneumatic system otherwise it will stay horribly weak. No point using a launching system for something you could do with your hand
M.C. Langer (author)  lemminggenocide4 years ago
What if you are a rescuer in the middle of a river and you don't have enough force in your hand for throwing a line? If you have a line gun, you could launch a cable to the nearest rescuer or to a branch. Having a steady position for launching a line is anything you don't have in many emergencies, and a spring powered gun could work.

You have a point with the hand thing. But, as I said, this is an iniciative, an open project. It will be good to see how you make the grappling gun with a pneumatic system.

you could use interchangable co2 canisters and attach the onto the side of the gun
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