Rubber Band Powered Helicopter

For this Engineering Principles project, we had to create a rotor-powered device capable of flying like a helicopter. Designing a helicopter has many considerations. For one, there are the 4 forces acting on the helicopter. There is lift, the force pulling up, weight, the gravitational force pulling down, and then thrust and drag, the forces pulling the helicopter forward and backwards. The original design of this helicopter came from another Instructable, and I modified it slightly to make improvements.

You will need the following:

Plastic propeller

1 small popsicle stick

3 rubber bands

Masking tape

1 Paperclip

Construction paper (cut into a symmetrical shape)

Small stirring straw

Bend the paperclip at the bottom into an acute angle, line it up with the bottom of the popsicle stick, and attach it with masking tape. Be sure it is attached securely, as this paperclip needs to withstand the heavy force of your rubber bands.

Cut your construction paper in a symmetrical shape roughly the width of the propeller. It may seem like flimsy paper is unnecessary, but this step is actually required to prevent the center from rotating and allowing the helicopter to fly. Feel free to cut it into any shape you want, so long as it does not obstruct the top of the helicopter.

Then, tape the paper on the popsicle stick. Make sure you put the tape on the side that has the paperclip sticking up (see photo), as this will prevent the rubber bands from hitting the paper.

(Optional step) This step is labeled as optional as the helicopter can still fly without the addition of the straw, but I have found that it works better with the extra stability. Tape the small stirring straw across the back of your paper. Tape it down in three places for the best results. The straw helps hold the paper outward better so it does not bend mid flight.

Attach the plastic propeller to the top of the popsicle stick. It should fit snugly on top of a normal small sized popsicle stick. Finally, hook your three rubber bands on the paperclip, and connect them to the hook on the plastic propeller. Depending on the thickness of the rubber bands, the number you use can vary, but with the normal sized bands I have found that three works the best.

To fly, simply twist the propeller to tighten the rubber bands. It only works if you twist a certain direction, you must twist it clockwise looking down on the top. A good way to figure out when to stop twisting is once the band begins rolling over on itself. When the full length of the bands are composed of these little bumps, you should be all set. Once it is twisted enough, hold the propeller and the bottom steady, hold it upright, and let go of both. It should fly upwards quickly and then fall back down. Success!