Introduction: Pen ''Rocket''

Are you the type of person who loves to see something soaring high into the air? Do you like rockets (on the cheap)? If so, this project is for you. In this Instructable, I will show you how to make a basic "rocket" from very simple materials that will go well over 100 feet (I believe this rocket is an original invention, but somebody may have invented it before I did and I just don't know about it. If you find another slingshot pen rocket design, please let me know.)

By the way, please read the entire ible before building anything - there is a variation/ modification at the end which changes the building process. I'm working on some other upgrades and improvements, and will post them when they're done. Please leave any comments if you have ideas for neat add-ons! I left this project very simple and open ended so that it would be easy to play around with the design, so have fun!


If I win the Epilog Challenge VI I will use the Zing 16 for engraving, making slot-together 3D geometric shapes, cutting out frames for robots (I'm thinking about building a hexapod right now), and making intricate pop-up cards. Please vote for me in the Epilog Challenge and the Glue Contest. Thanks!


Step 1: A More Detailed Introduction to This "rocket"

To begin with, it isn't technically a rocket (hence the " " around the word rocket, which I will now stop adding). It isn't a rocket because a rocket is a "vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction." (Wikipedia, Rocket). In other words, a rocket has to carry its own fuel source, and this fuel (or exhaust from it) must propel the rocket by exiting it, making the rocket move in the opposite direction.

So, this isn't a rocket, because, for power, it uses a rubber band catapult. For purposes of convenience, however, I will refer to it as a rocket. While the power system means that it's not a real rocket, it allows the fuel source to be fairly reusable. What's neat about this rocket is that it is made from just pens, rubber bands, cardboard, wire, and glue, but still goes quite far and looks impressive in flight. Personally, I think that kind of is what DIY is all about: using simple materials to do really neat things.

One other thing...

Disclaimer: This project involves a glue gun and an x-acto knife; the finished rocket is also fairly dangerous (It goes quite fast and would hurt a lot if it landed on you at the end of a vertical flight). Be careful; use your common sense, and if you hurt yourself or someone else, it's not my fault.

Step 2: Materials and Tools That You'll Need


For Rocket

1x pen (must be the type shown in the picture)

1x piece of cereal box-board (thin cardboard)

For Slingshot/ Launcher

1x pen

1x 3 in./ 7 cm piece of stranded wire (with insulation)

7x heavy-duty produce rubber bands ( broccoli rubber-bands) - you might want extras for when some break


x-acto knife

side-cutter pliers


glue gun... and some glue... : ) (glue is an important part of this project - it provides weight, fastens pieces of the rocket together, and acts as a holder for a sparkler in the improvement (step 13))

And that's it!

Step 3: Rocket - Removing Unnecessary Hardware

Open the pen and take out all of the hardware in it - you'll only be using the case (the red parts in the pictures).

Step 4: Rocket - Creating Catapult Hook

Take the side-cutters and snip off most of the pocket clip on the top end of the pen (study pic. 2 for how much to take). Next, use the x-acto knife to shave away a bit of the plastic under the clip (see pic. 4 for location and how much to take). That's all for the catapult hook.

Step 5: Rocket- Adding Weight and Fastening Together

Fill the top half of the rocket (the one with the hook) with glue. When it starts coming out the top, stop adding glue and screw the two halves of the pen back together. When the glue that came out the top cools to the point of just being gummy, shape it into a nice, even cone. (Don't shape it earlier unless you want burns.) This glue should help to keep the rocket from breaking when it lands on concrete or a rock after a particularly high flight.

Step 6: Rocket- Adding Fins

Cut a square of cardboard, cut it in half, and cut each half along the diagonal , corner to corner. This will give you four triangles. (This is my method for making fins; if you want to do something fancier, be my guest.) I use only three of them (I find that it makes the rocket easier to hold while launching). Put a line of glue along the rocket on the bottom half, and hold a fin in place there until it dries. Attach the other fins in the same manner so that they're spaced out evenly around the rocket (see pic. 6). Next, curl the bottom of each fin just a bit, all in the same direction. From the bottom, it should look like pic. 9. The last picture shows the finished rocket.

Step 7: Catapult- Modifying Pen

Open up the pen and remove all the hardware (like with the first one). Take the top half and use the x-acto knife to cut the plastic down right to the top of the pocket clip. Reattach the two halves of the pen.

Step 8: Catapult- Rubber Band Chain

This is the power source for the rocket. Take two rubber bands (I'm using a white one and an orange one, pic. 1), put one through the other (orange through white, pic. 2), and loop it back through itself (orange around white and through orange, pic. 2 and 3). Pull tight until it looks like pic. 5. repeat these steps until all seven rubber bands are joined together.

Step 9: Catapult- Wire Loop

This wire will be made into a loop for attaching the catapult to the rocket. It has a lot of pull acting on it, so the joint in the loop must be strong. To make it, strip about half an inch/ one cm off each end of the wire with the scissors, put it through one end of the rubber band chain, and divide the strands into four groups on each end (I'm doing mine without it being on the rubber band chain so the rubber bands don't get in the way of the pictures. Don't do this. It's no use if it isn't attached to the chain). Match the ends up (pic. 6) and twist the eight groups together in pairs (pic. 7), one group of each pair from each end. This will give you four larger groups (pic. 8). Twist these together in pairs (pic. 9), to give you to bundles (pic. 10). Twist the two bundles together and bend the twisted wires (pic. 11) over, like in pic. 12, so you don't prick yourself on them. Bend the loop so that it is an oval with the joint on one side (pic. 13).

Step 10: Catapult- Join the Pieces Together

Take the end of the rubber band chain without the wire loop and put the rubber band over the catapult pen. Slide it under the pocket clip, all the way up to where it is in pic. 2. Picture 3 shows the completed catapult.

And that's all the construction! You're ready to launch!

Step 11: Launching- Set Up

When preparing to launch, put the wire loop on the hook, as shown in pic. 1. Next, make sure that the catapult is set up like pic. 2, not pic. 3. If you attempt to launch as shown in pic. 3, you will probably snap the pocket clip off the catapult pen and the rubber band chain won't stay in place anymore. Finally, carefully hold the rocket between the fins to pull it back (pic. 4) and...

Step 12: Launching- Technique (and VIDEOS)

let it fly! Actually, just a moment. Because this isn't a Y-shaped slingshot, if you just release the rocket and keep the catapult arm still, the rocket will smash into the catapult pen, tangle in the rubber bands, and not go very far. Because of this, you have to move your catapult arm down a bit as you launch, so that the rocket goes just over the top end of the catapult pen. Picture Series 1 shows a good launch (notice where my arm is at various points of launch. Picture Series 2 shows a launch where I kept my catapult arm still, causing the rocket to hit the pen. Picture Series 3 shows the other common error- pulling the catapult arm down so quickly that the rocket moves in a curve and either doesn't release from the catapult or tumbles as it launches, causing a much lower and less graceful flight. A bit of practice will soon have you reliably launching well! Below are two launch videos.

Step 13: An Improvement

If you're a bit of a pyromaniac, you'll quickly appreciate how this rocket and a sparkler can be used to make a firework. For this modification, while doing step 5 you only half fill the top of the rocket with glue, leaving the top open (pic. 1). When the rocket is finished, you can take a sparkler, trim off most of the wire handle with your side-cutters (pic. 2), and stick it into the nose of your rocket, pushing the wire into the cooled glue part way down the inside (pic. 3,4, and 5). When launching, be careful to keep the sparkler and matches/ lighter away from the rubber band chain. Sorry about the lack of a video for how this looks in flight. I'll try to post one later, but don't get your hopes up (the first attempt's pictures and videos are all blurry... apparently my camera doesn't focus well in the dark). It looks cool when launched, but it's actually quite hot , and if you start a fire, it's not my fault. Don't do this in dry grass or forest.

I'm working on some other upgrades and improvements, and will post them when they're done. Please leave any comments if you have ideas for neat add-ons! I left this project very simple and open ended so that it would be easy to play around with the design.

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Epilog Challenge VI

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Epilog Challenge VI

Launch It! Contest

Participated in the
Launch It! Contest