Introduction: Make a Sling (weapon) Out of a Grocery Bag! (Plus Two Bonuses! "How Not to Use Scissors" & "Replace Bandaids With Sports Tape")

Picture of Make a Sling (weapon) Out of a Grocery Bag! (Plus Two Bonuses! "How Not to Use Scissors" & "Replace Bandaids With Sports Tape")

(I came up with this idea during the Recycling-themed contest, but I hadn't the chance to instructable-ize it till now.)

You're stuck on a island with no sign of human habitation except some litter bobbing at the shoreline. You need to hunt the wildlife for food (or, if you're a vegetarian: there's a vicious critter (or coconut) stalking you, and you must kill it).
What do you do?

Construct a make-shift sling out of a plastic bag!

My goal was to create a reasonable sling out of a plastic bag using the simplest possible construction.
It's not all that accurate, nor powerful, but you're using less than half a plastic bag.
You're getting quite a lot out of this little scrap of trash.

- A plastic bag (grocery bags work well, but some of the classier, thick mil bags won't)
- Scissors (also useful for close-quarters combat with that vicious critter!)
- ... and some bandages + first aid cream (see step 5)

General construction:
2 x ropes from twisted strips of plastic
1 x cradle from folded rectangle
1 x finger loop

Project takes about 10-20 minutes, possibly less.

Don't poke anyone's eye out, don't strangle puppies with the sling. General safety rules apply, but by and large, this sling is a rather tame weapon. (I think you need to be more conscientious that your left-over plastic isn't a choke hazard than over projectile injury.)
Honestly, I'm more likely to use this to lob crumpled paper at my friends than anything else, so I'm blatantly ignoring the "don't shoot people" rule.

Step 1: Snip, Snip

Picture of Snip, Snip

Get a bag.

Flatten it out so that the layers are neatly folded.

Across both sides, in line with the handles, cut two loops of plastic bag.
- With most grocery bags, the plastic is folded accordion-style and sealed at the handles
- If you trim about 1.5inches off the edge, you should end up with a continuous loop of plastic (with little flaps at what used to be the top of the handle and the bottom of the bag)

It might help to mark where to cut (I can't cut in a straight line unless I have guides)

Now, cut off one set of flaps so that you no longer have a loop, but a single strip of plastic.

Step 2: Twist!

Picture of Twist!

Tie a knot at each end of your plastic strips.

Start twisting one strip into a rope.
- You may find it helpful to use some anchoring device.
- Make sure you twist the entirety of the strip in one direction

Since you are working with a fairly long strip of plastic:
- The end you are twisting will be more compact
- Sections of the plastic may remain rather "fat"

Just pinch a stubborn section between your fingers and simply roll back and forth

Step 3: Sort-of-but-not-really Untwist!

Picture of Sort-of-but-not-really Untwist!

Hopefully the plastic is now reasonably circular in cross section.

Grab both ends in the same hand while anchoring the middle. (The accompanying photo was taken with my chin, so don't whine about it being blurry.)


Your rope should do some bizarre acrobatics and end up with both sides winding around each other.
- Tie a knot to secure the loose ends!

Chances are good that your doubled-up rope is rather loosely twisted.
- Continue twisting the plastic to tighten the strands a bit

Now go back to step 2 and repeat the process with your second strip of plastic.

Step 4: Start on the Cradle

Picture of Start on the Cradle

You now have two twisty ropes of plastic. Put them aside.

Grab the portion of the plastic bag that you haven't yet used (you didn't throw it out already, did you?)

Cut a rectangle about 5inches wide and 6inches long.
- The "5inches wide" is the more important measurement--you'll be trimming off excess length later

Don't cut yourself.

Step 5: A Brief Digression on First-aid

Picture of A Brief Digression on First-aid

Since I had my camera out, I figured I'd document the bandaging process while I was at it.

I've stopped buying commercial bandaids and have switched over to sports tape.

Using a bit of tissue with antibiotic first-aid cream, I covered the cut.

I tore off 3inches of sports tape and divided it into two strips

Tape. Tape. Fixed!

I've found that sports tape is pretty useful for bandaging fingertips: using a 1-2inch strip across the top of the finger and wrapping another 3 inches of tape around makes for a very secure binding.

Step 6: We Now Return to Your Regularly Scheduled Broadcast: the Cradle

Picture of We Now Return to Your Regularly Scheduled Broadcast: the Cradle

Take your rectangle of plastic (you didn't lose it in the shuffle to bandage your bleeding finger, did you?)
- Fold it in half
- And again

Pinch together one end and thread through the loop of one of your ropes
- You will probably wish to use the continuous loop (i.e. "not the one with knots")
- Tie the sling
- Repeat with other end, making sure you have about 3-4inches between the knots
- Trim off excess

Step 7: Finger Loop & Finish!

Picture of Finger Loop & Finish!
Cut a little rectangle of plastic approximately 1"x4"

Fold and twist it a bit and tie it into a small loop.

Now: loop the new little loop onto the knotted-end of your rope-loop and loop the little loop loosely over the rope.

Just... get it so that the little loop is secured one side of the sling, and pull the sling through the loop to create a larger area to accommodate your finger.
- This convoluted atrocity will be where the sling remains fastened to your hand. The other end will be the one released when you fling things.

Go ahead and hold your sling.
- Make adjustments if needed to get the cradle to sit level

Oh, hey, look: you've got more than half of your plastic bag remaining! Make more slings!
- This might be a very poor decision if you have siblings of similar age, or of exceptional belligerence

And to show that this sling can fling things:

Now, if only I had enough space to see if I could aim this sling... (And no, I wasn't aiming for the tupperware, I was aiming for the wall. I hit it, too.)


mark.harrop.948 (author)2014-09-17

2 more methods…

zachthebeast (author)2010-01-07

i am having trouble with step 6 can u give more detail????pls

Basically, If I understand this correctly, You must take a roughly 5"x6" piece and fold it in half twice length-wise and then tie an end to each rope like thing.

cleage001 (author)2011-11-09

Cute bandage.

benduy (author)2011-05-23

a easier way to kill a animal is to,stick the bag on its head, you have more of a chanch of hitting it! :)

DrPeper (author)2010-09-23

I wrote an instructable on how to make a 7 part braided rope from plastic bags, it might make a slightly more durable sling. Also I thought using the techniques posted elsewhere here on instructables which fuse many layers of plastic bags together using a clothing iron might make for an interesting idea for a cup/pouch for the rock.

But nice Instructable!  It got me thinking.

zigzagchris (author)2010-04-11

vaio jealousy

imshanedulong (author)2009-01-03

have a different way to make a sling:

It uses duct tape and tells you how to use it.

Matt21497 (author)imshanedulong2009-07-05

SPAM!!!!!! Ps in your comment you forgot to say tell your friends about it (=

imshanedulong (author)Matt214972009-07-18

Sorry. I didn't mean it as spam, I was just telling people other ways to make these!

Matt21497 (author)imshanedulong2009-07-19

I was joking didnt you read the small print?

Matt21497 (author)2009-07-05

You stole my idea for an instructables no no no no NO!

jackandjill (author)2007-12-21

you would proberbly be safer punching the coconut

bubba j (author)jackandjill2009-06-02

na i propboply would stab it with a pice of sheet metal from the wreak

mashedpotato13 (author)2008-12-08

Do you HAVE to use sports tape??

pandaboy292 (author)2008-10-27

i alaws draw a smile face on my band-aids.nice instructable i'll have to try it.

cj380 (author)2008-08-03

can i make a sling from jeans pants i meant for the pouch.whill it stay there or tear in half.

ryzellon (author)cj3802008-08-04

It should work fine.

Lemon_Asakura (author)2008-03-25

Cool! I am soooo making this!

Kaiven (author)2008-03-05

HOLY SNAP!!! I made this, like, quick, went outside and threw rocks into my coldisac(sp?) I hit a tree in someones backyard on the OTHER end of the coldisac. this is great. Water proof too

Kaiven (author)2008-03-05

swing it round a couple of times for momentum/velocity

Kiteman (author)2008-02-23

I made these with my science club this week - string and carrier-bag, bodged together with minimal skill, and they still had tennis-balls flying all over the playground. Much fun.

KLUTZYengineer (author)2008-02-23

Well - interesting. I really liked the smiley-face home made first-aid ( highlight of the Instructable )

dataphool (author)2007-09-26

Very instructive! Especially, steps 4 and 5, where you wisely elected not to give the scissors a further opportunity to perform a further indignity on your person.

Although, I try to recycle, and recycle, and recycle; the pesky little beasties threaten to overwhelm my home if I fail to maintain constant vigilance. It was so much simpler, when I was a boy and we merely had brown paper bags. Of course, we had a different problem..

Deadpunk (author)2007-09-20

Speaking has a vegetarain and the ocasional out doorsmen thoughs coconuts can be very dangerous critters what whith there tendency to use arial attacks directed right at your nogen. But any ways great instructable my family has tons of those plastic bags laying around i might I think i'm gona put a couple of them towards something constructive so i can then induldge in the plesures of being destructive :p

Aburame Shino (author)2007-09-16

Bravo! Though I am still a wibble beet unclear on how you did Step 1, cutting the handle in half, and it stil be completely intact or something in the picture. O.o Eh. You get what I mean. Otherwise, it are the pwnage.

ryzellon (author)Aburame Shino2007-09-16

Try the third image at step 1, and let me know if it makes sense, or what I still need to make clearer.

Aburame Shino (author)ryzellon2007-09-20

Thank you very much! It helps a lot. I don't know if you just added that, or if I just overlooked it. =P

Wolfsire (author)2007-09-13

Not a bad instructable or concept. I've seen a few sling making site and I think your might be too small to be very effective. I know you qualified it, but maybe I can offer some improvements. Basically, make it bigger. IIRC, the sites referenced specific measurements based on arm length etc. I have also experimented a fair amount with making cordage out of plastic bags. I prefer to cut off the handles and cut off the melt-sealed bottom. That give you a loop. You can create a chain by linking several of these together to get longer cordage. You can make the cordage thinner by cutting the loop into several loops, but this stuff is not that strong, so the smaller you go, the easer it is to break. Your technique for smoothing out the cordage is very similar to mine, but I would say keep twisting (before folding in half and letting it coil around itself) until it starts to kink in places and coil at points by itself. This will make a tighter cord. You might also consider using multiple chains of loops for a single cord for more thinkness and strength. If it is tight, you get more strength per given thinkness. I would definately consider using you idea, but if I found twenty garbage bags on the beach, I would use them all for a sling, or maybe for a cordage backed bundle bow. :-)

ryzellon (author)Wolfsire2007-09-13

My goal was to come up with the simplest construction for a reasonable sling (from a plastic bag), and I hope I did succeed. I have no doubt it's really ineffective, though. I get better aim when throwing with my left foot, than with the sling! This lil' sling is probably best suited to kids running around indoors, lobbing Nerf balls than anything else. I'm working on building a "real" sling, but I'm finding that urban areas are rather poor locations for testing projectile weapons. Could you describe, diagram or photograph what you're describing with "cutting off the handles (& bottom)" and the resultant loop? I'm not sure of how you mean it, but I'm guessing the loop is the body of the bag? (The rest of your suggestions are plenty clear, though.) Continuing with the plastic-bags-as-a-weapons-building-material, what about using bags to provide torsion for a small ballista? Teaspoon ballista, powered by plastic bags! (Though with twenty garbage bags, I bet you could get a much heftier ballista than that.)

Wolfsire (author)ryzellon2007-09-15

Sorry, not pic. Your instructable cut the two pleat side of the bag. The handles and bottom are the other two of the for sides when laid flat. The handles are the part you normally carry the bag with. The bottom is opposte where it is melted closed. Platic bags and plastic spoon? Sounds interesting.

hunter cd (author)2007-09-15

nice sling

pyro13 (author)2007-09-13

nice. ive never thot of this... thanks for the idea

Wolfsire (author)2007-09-13

Oh, yeah, maybe those vegetarians can use the sling to knock down coconuts.

About This Instructable




More by ryzellon:Repairing a Nintendo DS LiteMake a sling (weapon) out of a grocery bag! (Plus two bonuses! "How not to use scissors" & "Replace bandaids with sports tape")Chainmail(le) Primer: Making Jewelry-Size Rings for Weaving Chainmail
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