Tiny, Telescoping Blow Dart

Introduction: Tiny, Telescoping Blow Dart

About: What's up nerds? My name is Jeremy and I am currently in college majoring in mechanical engineering. Being active is the name of the game and I enjoy most outdoor sports and like to tinker and build on the sid…

Reusable straws are all the rage right about now, but I don't use them. It's not because I hate turtles or the environment, I just don't use straws which seems to be a simpler solution. Unfortunately, the modern beverage industry has created a dependence on straws so here we are. Due to a free swag bag I now own a reusable metal straw so I was brainstorming different uses for it aside from drinking. The most fun one was a miniature, portable blow dart. This took minimal time and tools to make and is fun to mess around with. Follow along if you're remotely interested and if not, do it anyways to make me feel better.


Most supplies can be substituted for something similar aside from the tools.

  1. telescoping straw (see next step for where to find them)
  2. toothpicks
  3. paper
  4. tape
  5. thread
  6. cotton ball/polyester stuffing
  7. scissors
  8. hacksaw
  9. thin file

Step 1: Acquiring Your Weapon

Reusable straws are pretty common right about now, so much so that I've seen them given away as swag at multiple different events from conferences to career fairs. Many of them are telescoping and come in a plastic case like mine in the pictures ... the perfect disguise. Look around the next time you're at such an event, especially at the end. No one wants to lug a cardboard box of straws back home with them so they'll be eager to hand them off. Grab one for yourself, one for friend, and one for good luck.

If you can't find any freebies at events or all the events are still cancelled because of the coronavirus just search "telescoping straw" on Amazon and take your pick of hundreds of versions of the same thing.

If you're seriously committed or have a lot of interested friends you could order in bulk from a promotional company and get a few hundred for a dollar or two per straw. Plus then you can brand them however you want.

Step 2: Mod the Straw

We need to make a few tweaks to the straw for optimal performance. Some come with a cleaning rod inside, take this out and keep it for removing stuck darts. The silicone bite tab at the end should also be pulled off to make loading your dart easier. The bite tab can also be slid back on if you want to use your blow gun as a straw for some reason. If you look closely at the end, you'll see a small curve around the lip on the beverage end. This will catch on the dart and ruin your soon to be flawless aim so we need to take it off. This can be done with a hacksaw or a file if you are determined. Take off as little as possible so you can still grab the end to extend the straw. Clamp lightly while cutting so you don't crush the straw. A dowel can be inserted from the wider end of the straw to provide some stiffness. I also used the file to remove the burrs after cutting and the final image shows the new, flat edge.

Step 3: Craft the Darts

Attaching feathers to an arrow for a bow is called fletching, what we'll do here is nowhere near as technical or important, but I wanted you to know that. Basically we just need something to stabilize the dart and keep it straight in flight while we hunt small rodents or large bugs. Toothpicks are the ideal body since they are straight, sharp and cheap. Just remove any decorations or whatnot on the toothpick. You could try a sewing needle if you want to take out something beefy like cockroach, but needles are much more finicky to work with.

There are two main ways I have found to make the fletching: paper cones or something fluffy. Both methods are simple so I would try both and see your preference. Either version will eventually get damp from your breath as you blow into the straw so make a few darts.

Paper Cones:

The cone traps the air and forces the dart out of the straw, plus is easy to make and replaceable. Notebook or printer paper and scotch tape are a good combo since they are thin and light.

  1. Cut a piece of paper into a circle roughly the size of a quarter
  2. Poke a hole in the center with a toothpick and then cut the paper in half
  3. Roll the semicircle into a cone (the thinner, the better) and tape it together
  4. Force the toothpick through the hole at the bottom and then tape it the cone in place
  5. Covering the cone in tape makes it more durable and protects against moisture
  6. Load the dart backwards in the narrow end of the straw and mark the cone at the edge of the lip
  7. Cut along the mark and then trim as needed to get the cone to fit within the narrow end

Fluff and Stuff:

Same deal as the cone, but looks more traditional and is a little more forgiving in terms of size since the materials can compact and expand. Polyester batting is durable and can handle moisture, but cotton balls are easier to find so take your pick.

  1. Tie about 6-8 inches of thread close to one end of the toothpick
  2. Take a small bundle of cotton or polyester and pinch it onto the end closest to the string
  3. Wrap thread around the bottom of the fluff and then rotate the toothpick to wrap the rest of the thread
  4. Wind the thread up the fluff towards the end of the toothpick then stop and tie it off
  5. Load the dart into the narrow end and pull off fluff as needed to get it to fit

Step 4: Prototype Darts

Before settling on the paper cone and cotton tuft darts I had a few different versions in mind. They would have been a full on arsenal if they worked, but they didn't. Feel free to try these out or make up your own and let me know if you find anything else that works.

Wire Shaft:

The idea was to make a heavy duty, armor piercing (not really) dart for heavy duty targets. I hammered some wire flat and then filed it to a point, but the wire is too heavy to be effectively shot by the blowgun and it just tumbles out of the end. I tried this with both the cone and the tuft fletching and neither worked.

Paracord Tuft:

I wanted to see if this worked since this method would be way easier to do in the field or outdoors. I cut a one inch section of paracord and rolled one end between my fingers and plucked at it to fray the fibers and create a tuft. I then pushed the toothpick through it and taped the non frayed end to the toothpick. This did not provide enough resistance to airflow in the blowgun so it it just sat there or fell out slowly.

Step 5: Ready...Aim...Fire (up Your Lungs and Blow)

Here is the fun part. Set up some paper targets and start testing. I prefer to load the darts into the wide end, but the fluffy ended darts sometimes work better if you load them into the narrow end. Try to slide the darts in straight so they don't hit the metal rim inside the telescoping portions of the straw. If they do get stuck, just collapse the straw and push or pull them out with a toothpick or pliers.

When "shooting" seal your lips around the straw and use one hard, fast exhale, like you are trying to blow a wasp off your arm. The range is pretty impressive given the size of the darts, but there is really only enough force and point on the toothpick to puncture some paper or a very small enemy. Be careful around people as the darts don't always fly straight and can pull some interesting aerial maneuvers. Hitting someone with a tiny dart might offset how cool you just became by making one.

Note: The paper cone will lie along the bottom of the straw since the cone is thinner than the wide end, but the tufted dart will fill up the wide end of the straw and compress as it moves along.

Step 6: Storage and Transport

If you have one of the freebie straws like me it comes with a lovely plastic storage tube, perfect for carrying into dangerous situations. One dart can be loosely slid in each end and fit in the tube since we removed the bite tab. The plastic clip that comes with the straw sucks (ha ha straw pun) so replace it with a better carabiner or clip. I also scratched off the original lettering and added a much better label with some tape and a sharpie. You could sand it off, tape over it, leave it untouched, go crazy with it.

Step 7: The Last Straw

Couldn't resist the title. I have entered this Instructable in the TINY Speed Challenge since it is both tiny, and was hopefully speedy. I haven't written an Instructable in a few years so hopefully this can be my glorious return, but that's up to you and the judges to decide. I would also be happy to hear of any other uses for these collapsing straws because I'm definitely not going to start using them to drink any time soon.

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    11 months ago

    Ive been trying to perfect my blow dart mech for a while now this helped quite a bit and gave me a lot of new ideas! thanks a ton brother


    3 years ago

    Love the collapsing mech!
    I bet if you attached a pen nib onto the front it'd make a nifty writing tool :D


    Reply 3 years ago

    A pen nib is a good idea, there's enough room in the case that it would likely still fit, even with the darts, thanks for the suggestion!