For this project I’m going to show you how to make exploding tipped blow darts. Throw
them at a hard surface, and these little flyer crackers explode on impact, making a startling
little bang as they do. You can throw them by hand, or use them with the blowgun we made
in a previous project. But either way, these quick and easy cap crackers, are sure to give
you a satisfying bang, for your buck.
Let’s start this project with a pack of ring caps, some paper snow-cone cups, and
#6 machine screws.
The screws I found are 2” long, and come in a pack of 5 for about a dollar. And if
you got the same pack I did, you’ll find 5 hex nuts in there as well, which should
come in handy in just a minute.
Ok let’s set a snow-cone on the table, pointy side facing up, then tear off a small strip
of duct-tape. Stick the tape on the cone so the edge is a little higher than the tip,
then wrap the ends around one at a time. I’m using duct-tape because it will help reinforce
the paper, and make it a little more weather resistant.
Now if you don’t have paper snow-cones handy, it’s no problem. You can always make your
own cones out of paper, or sticky notes, like we did in the laser blowgun project.
Ok, let’s push the tip of the cone into a piece of 1/2” PVC tubing, and you’ll
see the edges mark a little indent at the top of the cone, the same size as the tube.
So if you flatten the cone and cut along the inside markings at the tip, you’ll end up
with a little stabilizer cone the perfect size for your darts.
While we’re here, let’s cut a small piece off the very tip as well, because we’ll
need this small hole for the screw to fit through in just a second.
I made 4 more stabilizer cones in just a couple of minutes, and now that we have improvised
fletchings for each of the 5 screws, let’s get busy putting these cap darts together.
To set the dart cones in place, simply pull a screw through the hole at the tip, until
the head catches on the inside of the cone.
And to prep it for gluing, try threading a nut onto the very tip of the screw. You’ll
see this way, the darts stand upright with the open end facing upward. Which is really
cool, because now we can easily squirt a dab of hot glue in the top, and seal the two together.
You’ll only need to fill the cones about halfway with hot glue, then give them a couple
of minutes, to cool and set.
Now to finish the darts off, we need to add a little weight to the tip so they’ll fly
straight. And you can see that shifting the center of gravity as easy as threading a second
nut into position at the top. The nuts should sit about 1/4” back from the tip, and if
you want to make sure they don’t move out of place, try dripping a little thread lock,
or super glue in-between the threads.
If you’re in the mood to add a little style to your darts, try picking up a pack of brass
#6 screw-nuts like these. By changing the colors of your hex nuts, you can give your
darts a bit of class.
Alright, our cap dart is finished and ready for action. We just need to charge the
tip so it’ll explode on impact. And that’s only as difficult as reaching for a pack of
ring caps. I found mine at a local super center, and sometimes you can find them at the dollar store as well.
Use a pair of scissors to slowly and carefully cut the individual caps off the rings, making
sure you don’t accidentally cut through them. And within seconds, you’ll have yourself
8 impact sensitive blast caps, ready to go.
Just for fun, I went ahead and cut the caps off every ring in the package and ended up
with 216 explosive charges, at an average cost of a penny each. That works out to about
a hundred bangs for your buck, not bad.
Now looking around for a convenient place to store these blast caps, I realized the
container for the Krazy Glue could be a really great option. It’s pretty much garbage anyway,
but rather than throwing it away, let’s put it to good use. Just like that, we’ve
got a pocket-sized storage container, filled to the brim with extra ammo.
Now the reason I chose #6 machine screws for these darts was because they’re the perfect
size for these particular ring caps. And to load the detonator cap, all you need to do
is slowly and carefully, push the bolt straight down inside the cup. That’s how easy it is to lock and load.
It’s impact sensitive, so to crack the caps, try dangling the dart high above the sidewalk,
then simply let it go. You’ll see the darts pop as soon as they make contact with a hard
surface, and they make a satisfying bang every time they do. Which should be just loud enough
to startle anyone not paying close attention.
Now I designed these darts to be used with the laser blowgun we made in a previous project.
And even though they’re a heavier kind of ammunition, they’re still impressively accurate
at close range. When the darts hit a wooden target, the force of the explosion actually
blasts little chunks of wood out of the center. So even though ring caps are relatively safe
for the most part, it is important to use caution, and be extra careful where you aim them.
If you don’t have a blowgun, just try throwing them by hand. They throw the same way you’d
launch a dart, and if you lob one high into the sky, it’ll plummet to the ground
and impact with a crack.
By the way, you can pack more power into your explosions by layering up the blast pads.
I tried using a small precision screwdriver to carefully pry the pads out of the cups
one at a time, then pack 4 of them into one single cup. The modified caps get loaded the
exact same way, the only difference is that this time, the explosion makes your ears ring a little bit longer.
Well now you know how to convert machine screws and ring caps, into a handful of impact sensitive
cap darts. So whether you intend on making a handful of exploding stun darts for your
blowgun quiver, or just making a simple toy for your kids to explore science, a homemade
cap dart is sure to be a blast.
By the way, if you want an even cheaper option, try using 2” finishing nails like these.
They work perfectly well for blow darts, and you can make 40 of them for around $2.
Well that’s it for now. If you like this project perhaps you’ll like some of my others.
Check them out at www.thekingofrandom.com