Rubberband Helicopter

This is our design process for a rubberband powered helicopter, created by Matthew Newell, Conor Dillon, Dean Manos, and Aidan Kielinen.

Instructable created by Matthew Newell

A helicopter has to combat four forces acting upon it: lift, weight, thrust, and drag. We needed to take these forces into account when creating our design.

Our research started from various different instructables, youtube videos, and other projects created by creative individuals. We took inspiration from many of these sources while still creating our own creative build.

Although we originally wanted to create a cube shaped drone design, we came across the idea of a trianular drone based build due to the strength and balance of a triangle. We decided to use the materials of balsa wood and 3D printed objects mainly due to the changeability and freedom from using such materials.

Our supplies and process for each step of the way is below!

Supplies:

Balsa wood

3D printer and filament

Rubber bands

Plastic bags

Beads

Paperclips

Hot glue and super glue

Glue gun

Exacto Saw

We started by creating 3 rectangular frames for the helicopter that measured 25 cm by 10 cm. We simply measured and cut the balsa wood, and then hot glued them together.

Once we had the frames and were ready to start the construction process, we made a last-minute modification to the design. Originally, we planned to have a triangular-shaped drone design, but we changed to Y-shaped design. This would use most of the same aspects of the original design, but would use a central hub in the middle of where the frames meet to power the build. This would be 3D printed to achieve exactly what we want with ease.

This modification would also remove the "box" under the rotors. This would provide for a more open design with less weight contributing to the drag of the helicopter. Overall, this change would make a simple alteration to the structure and lead to a helicopter that is easier to work with.

Next, we 3D printed 3 different pieces to use in our prototype. The first was a tube-shaped central hub. This would serve as the center to connect the entire helicopter, as well as to power the rotors with the rubber bands. The second piece was to be connected to the top of the central hub. This would be spun by the rubber bands and spin the rotors in result. Lastly, we printed 3 small rotor shaft holders to connect to the end of each of the frames and hold the rotors.

Afterwards, we used hot glue to connect the frames to the central hub. We used a protractor to measure where we should attach the frames so they are evenly spaced.

The next step consisted of us using hot glue and super glue to attach pieces for the rubber bands. The first piece went on one end of the central hub. We connected a paperclip in the shape of a hook to hold one end of the rubber band. The second connection of a hook was onto the piece going into the end of the central hub. As the rubber band was held on both hooks, we would spin the top part to power the design.

Our next step was to finish the rotors. We measured and attached pieces of balsa wood to serve as the rotors. We then went on to attach plastic to the balsa wood to catch air.

Unfortunately, this was our final step. We soon realized that our design was impossible to work due to the weight and fragility of some of our 3D printed pieces. We learned a great deal about how we should have went about it, but more importantly we learned the engineering process and how to correct failure.

We did not get the chance to test the helicopter but we could infer the results. We expected failure through weight and even the main powering mechanism because we could not get it to work.

If we could redo this project we would be more methodical about the process. We would ensure that we were printing light and simple, and spend more time on building an efficient helicopter.