A while back I found instructions for a clever office supply bow and arrow and was inspired. I decided to step things up a notch. In the end I had a nifty little "crossbow" that straps to the inner arm, perfectly concealed by a loose sleeve. With just a flick of the wrist, your classmates won't know what hit them!

This is the second incarnation of the design. The first was held together entirely with gorilla tape and I only had enough pictures for a slide show.

Though not as powerful as other designs, this thing can still do some damage. Do not point it toward the face, it could easily take out an eye. Do not aim anywhere that can potentially damage something, it's awkward aiming with the forearm, so its accuracy can be hit or miss (pun intended).

Step 1: You Will Need...


At least three Bic ballpoint pens
A thin rubber band*
A clothespin*
Several craft (Popsicle) sticks
A length of strong thread*
Duct tape (No project is complete without it!)
A ring (optional)

*take care selecting these items. Too strong a rubber band can't be held back by the clothespin. Too strong a clothespin will break your thread. If everything is too strong you risk yanking the whole thing off your arm when you go to fire.

I was able to rig one of these with mostly scissors and a roll of gorilla tape in the back of class, so don't sweat the details. However, I have found these to work quite well:

A hot glue gun
A small-bit drill
A fine-tooth saw
Duct Tape (So important it deserves to be named twice.)

<p>That looks AWESOME!!!!! can't wait to make it.</p>
works awesome
I've attempted to build this while removing the string, because pressing the clip feels satisfying. It still works! Still can't find a clip, but replacing the popsicle sticks with two pieces of cardboard (with the lines of both pieces intersecting) makes it fairly sturdy! All in all, this is a great project (for all ages) that has room for customization.
<p>If you don't want it to fall when your hand is down you should have the clip hold the arrow. Why not?</p>
<p>I'm want to try to modify the materials to shoot across the room. The jerk who throws crap at people won't know what hit him. XD Thanks</p>
<p>I want to say one word.</p><p>AWESOME</p>
It is awsome
Amazing just amazing totally going to make
is there any other substitute for the pens?
Dude. That is so awesome I'm gunna DIE! I will totally make this!
How far does it shoot
BTW, i have possible ideas for one that fires multiple instead of just one.
Thanks man! i have been looking throughout this whole site and yous is by FAR... THE BEST ONE! And it works good. When i brought it to class some kid tried to copy it, but he somehow shot himself in the face! (so i shot him afterwards)
I found that a scew driver and a drill work best instead of an exacto knife. (More kid friendly) ;D
Is their any other device I could substitute the clothespin with
Something I'm looking forward to getting sent to the principal's office for c;
I realised why it needs sturdy string,i keep flicking my wrist hardly and the string just breaks
I want to find an Instructable that is a K'nex version of this crossbow.
I don't understand how to tie the string to the clothespin and connect it to the ring...
Drill a hole through both both tabs on the end you pinch together. Tie the string through the hole on the outside tab, then run the loose end through the hole in the inside tab and underneath the whole crossbow.
thanks!!! it works perfectly its very comfortable! and at the first shot i accidently&nbsp; shot my finger and it hurt alot but evrybody was afraid of me with that thing :D<br /> <br />
It's the same for me with a blowgun I made.
Outstanding! Spread the fear! &gt;:D<br /> And hey, now you know it works really well.<br />
fake hand
Well, of course it's fake, lol. You try taking a picture of your own hand while holding your arm flat down on the table xDDD
With a crossbow strapped to it lol
Actually that's my hand. It's directly under the light which is flattening out the features or something. Though it was a little tricky getting this shot.
i just got finished making something similar to this. it's like one of those spring loaded spears, but it is a down sized version that you hold exactly like this. it only took 3 k'nex, a rubber band, and some gorilla tape. I'm actually surprised at how well it works when i use it right. i do plan on making the crossbow shown as well too.
i took the seemingly obsolete remainder of the pen from step 3 and put it in the roll.
Ooohh... that was smart.
as i said before, i didnt cut another pen; i used previously cut ones.
Err... I made mine and it shot the ink cartridge a foot or less, and it just dove down... Any solutions to make it shoot further and stronger?
I'd just tighten the rubber band. I usually loop mine around the nose piece.
can you use cardboard?
Yes, I think, but this wouldn't be so resistent
nice work, looks sweet. for the 3.0 version, u should make it so u cant see the crossbow at all<br /> <br />
How do you mean? It's already pretty much completely concealable under a long sleeve. I'm always up for refining the design, but I'm not sure how to get it any less visible unless I used 'The One Ring' for the trigger.<br />
I'll use a ring-ized paper clip
i really dont think it could be anymore descreit
Can you use also skewers for ammos?
If it fits I don't see why not. I wouldn't point that at anybody, though.
Thanks! Anyways, I think I would tape the end. <br>We love duct tape! <br>We love this proyect!
hey ducttapeninja could u make a hidden blade like this instructable
oh and about how long are the strips of tape you use for the rubberband holder?

About This Instructable




Bio: I just like to make things. I dabble in a lot of mediums and usually don't like to spend money on parts, so most ... More »
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