Office Booby Trap




This is a fun little Booby Trap that fires objects when a trip wire is pulled.
It is made from a few simple items that can be found around the office or home.

Needless to say, be careful what you fire at people.

Step 1: What You Will Need

3 Paper clips
Bottle Top
Rubber Band
Pliers (Needle-nose)
2 Drawing Pins

Step 2: Straighten the Paper Clips

Using your Pliers straighten the 3 Paper Clips.

Step 3: Make Four Holes in the Bottle Top

Turn the Bottle Top upwards and then using one of the Drawing Pins, make 2 holes at either end.

Make the holes at one end approx 2cm apart, and at the other end 1.5cm apart.

Step 4: Bend a Paper Clip and Insert Into Bottle Cap

Now bend one of the Paper Clips using the Pliers so that there is a 2cm gap in the middle of the two 'arms'.
This is going to be pushed through the holes in the Bottle Cap that are 2cm apart, so that the arms point out the top.

Step 5: Bend the Arms and Attach the Rubber Band

Bends both the arms outwards slightly so they are at a 45 degree angle.
To attach the Rubber Band to the arms we need to roughly cut out a 4cm section of the Rubber Band and tie a knot in each end.

Now rest the Rubber Band between the tips of the two arms, then bend the tips of the arms around the Rubber Band and clamp them down. Making sure there is no room for the knots to slip though.

An image of the finished result of this Step is attached as the second Picture File.

Step 6: Bend the Other Paper Clip and Push Into Bottle Cap

Exactly like Step 4, bend a Paper Clip but this time leave a 1.5cm gap in the middle.
Then push it through the two remaining holes.

Step 7: Bend the Two New Arms

These two arms are what are going to hold the Firing-Latch in place, so they need to be bent closer together, and then have a loop made on the top of each.

You may find that before making the loops you need to cut around 0.5cm off the top of the arms, just to ensure that it is at half the height of the arms holding the Rubber Bands.

Do not fully close the loops as you will need to slip the Latch through them.

Step 8: Making the Firing-Latch

This is the part of the Booby Trap that hooks onto the stretched Rubber Band until the trip wire is pulled.

You create this by bending your last Paper Clip in half, bending the end so that it forms a hook and then bending the two ends in on each other.
You can then attach it to the empty arms and tighten the loops you created in the last Step.

View the pictures below to gain a full understanding of what you need to do with the Paper Clip.
To adjust the sensitivty of your Booby Trap you simply change the angle of the hook.

Step 9: Attaching the Trip Wire

The trip wire is used to make the Latch raise, thus releasing the Rubber Band.

The trip wire is attached by making two holes in the Bottle Top. One on the top underneath the latch and the other below it, on the side.
Then feed through the string and tie it to the centre of the latch.

Step 10: Fixing It Down

When you set your Booby Trap you are going to want to stop it moving about and remove the possibility of being pulled over by the Trip Wire.

To give you the ability to fixed down make 4 holes. Two on one side of the Bottle Top and two on the other. Then thread some string through the holes and tie a knot.

All you need do now in order to fix your Booby Trap in place is to either Sticky Tape the string down, or use the two Drawing Pins like in the picture below.

This also gives it the ability to be fixed vertically to a door frame etc.

Step 11: Finished! - Try It Out

It is now time to test your Booby Trap.

To load your Booby Trap simply pull back the Rubber Band and hook it on the Latches hook.
Then put whatever projectile you wish in front of the Rubber Band. You'll be surprised how far it shoots the object.

Below is a video of me testing the Booby Trap to make sure everything was working correctly.

Click here to view the video
*The video has been deleted from the original service I'd uploaded it to. I will be uploading it to YouTube shortly.

I wanted to make my Booby Trap more sensitive after filming this video. So altered the angle of the latches hook.

Comments, Pictures and Ideas are all greatly appreciated.

Any updates to this How-To will appear on my website

Participated in the
The Instructables Book Contest



    • Backyard Contest

      Backyard Contest
    • Stone Concrete and Cement Contest

      Stone Concrete and Cement Contest
    • Classroom Science Contest

      Classroom Science Contest

    544 Discussions


    3 years ago on Introduction

    This is genius, I super-sized this and made it fit in my school locker, attaching the string to the door. The string goes through to the outside through the secondary lock hole, with 3 chain links tied to it. On top of it all, there is a key-lock on the chain, preventing someone from simply disarming it. on the outside you only see a chain link and key-lock, but can still open easily. so open the locker and... snap! It slings a plastic long-dart straight at them. and to dis-arm it from the outside, remove the lock.

    1 reply

    6 years ago

    It didn't work for me! I think my paper clips were too weak or something?? When I hooked the rubber band in place it would just pull back the paper clips instead of stretching the elastic

    1 reply

    Reply 5 years ago on Introduction

    try using matchsticks and strengthining them with hot glue


    5 years ago on Step 1

    whats the how to do it


    6 years ago

    I followed the steps step by step yet it only shoots 3 inches. Any suggestions?


    6 years ago on Introduction

    its the best among all instructables.i like this the most.


    6 years ago on Step 11

    This is the best instructable I HAVE SEEN SO FAR


    6 years ago on Introduction

    This looks brilliant!
    I'm thinking of adapting this to fire pens (
    If i can get it working i'll upload it, should result in pretty good accuracy