How to Make a Rubber Band Powered Helicopter

Instructions on how to build a rubber band powered helicopter using simple materials. This is a quick and easy build and can stay in suspended in the air for at least 20 seconds, longer with minor adjustments. These instructions include the dimensions of our materials, but the dimensions can be changed depending on the scale you wish to build yours, or to change any adjustments to make yours fly even better.

The Design/Building Process

We had experimented with making paper helicopters that didn't necessarily fly up, but spun to slow their descent when dropped from a height. We kept the overall shape of those helicopters and the fact that they spun in order to fly, but we added another set of propellers in hopes that it would generate lift. Additionally, the paper helicopters were able to fly at all because they were made out of paper, which is naturally very lightweight. We used balsa wood to keep our helicopter as light as we could, maxing out at around 10 grams, in order to increase the chance of actually flying.

1. 4 1cm x 3cm balsa wood

2. 2 16cm x 1cm balsa wood

3. 4 .5cm x 40cm balsa wood

4. 1 .25cm sheet of balsa wood.

5. 2 large paper clips

6. 2-4 rubber bands

7. 2 6/0 size beads

8. Thin reusable plastic (we used a plastic propeller as well as a bottle cap for the other side)

9. Thin trash bag

10. Coffee stir stick

1. Start by cutting out your pieces of balsa wood. There should be four shorter pieces, and two long pieces.

2. Place your two long pieces parallel to one another and place the shorter pieces horizontally on each end and on each side.

3. Glue each of these pieces together where they intersect. We recommend using super glue, but wood glue would work best. Avoid hot glue as it adds a lot of weight.

4. Using a thin coffee straw, cut it into two 2cm pieces and glue them in between the short pieces of balsa wood. They should be parallel to the long pieces, and horizontal to the short pieces.

1. Cut four 20 cm balsa wood sticks.

2. Cut out two balsa wood circles with 1.5 cm diameters.

3. Glue one of the balsa wood sticks aligned with the center of the circle.

4. Glue another stick on the opposite side of the circle, skewed so the ends of the sticks are 10 cm.

5. Poke a hole in the center of the wing skeleton and insert straitened paper clip, folded along the the top to secure it.

6. Glue a cut up trash bag along one side of the wing skeleton.

7. Repeat with the other materials, the exact same way.

Once you're finished building the wings and the base, we need to attach them all together.

1. To create the disk that stops the bead from getting stuck on the coffee straw, cut a small circle, (approx. 1cm in diameter) and cut a tiny hole in the center

2. Put a single bead onto the straightened paperclip attached to the wings.

3. Slide the disk made in step one onto the paperclip as well, and then insert both sides onto the base. (Make side the wings are facing opposite directions to create lift!)

4. Now that they are all together, we can bend the paperclips to to can hold onto the rubber bands. Do this by curving them upwards into a "c" shape.

5. The final step is to attach the rubber bands to both sides, wind it up, and release!

The helicopter remained in the air for about 20 seconds when dropped from a height. However, it did not hover, nor did it fly up. It did glide and have a slowed descent. This could be improved by increasing the wingspan, increasing the number of rubber bands, or a number of other adjustments.

Adjustments/Modifications

Along the way of building our helicopter, we noticed some things were a little bit off. Some of the measurements are not exactly perfect and it make our helicopter fly terribly. Of course, our goal was to make the helicopter fly as long as possible. The biggest modification we made was the length of the wings. It has started at 10cm in length on either side. After lots of testing, the wings actually ended up breaking a lot of times we had tested it. It crash-landed resulting in the breaking. So, we used basic knowledge and determines that the surface area is a big factor is how long it stays in the air. We made the wings double the size and it worked wonders on how it flew. We changed it to 20cm long on either side and made our helicopter not crash land and fly longer. Officially, the helicopter improved it's flight time by nearly ten seconds. These wings also did not add much weight onto the helicopter (+1oz). We also added in supports next to the straw so it wouldn't slip and we added more rubber bands in order for more power. The picture on Step 1 (last image) is an example of the short wings, and the picture on Step 2/3 is and example of the modification on the wings. The other modifications were made and seen in the picture on Step 2 (last image).The Supports are in the inside of the structure and are hard to see, but they are very mighty in holding up the helicopter!