How I Scaled Up a Paper Airplane
As a kid, I loved making paper airplanes. I would sit and fold for hours and I would fly all different types of styles of paper air planes to try and make ones that would fly the longest distance, or stay aloft for the longest, or do the coolest loops and tricks. I would build all different types and would really study each ones flight pattern to better understand the aerodynamics of the planes and how each paper winged surface, the center of gravity, the type of paper, where the placement of the glue or paper clip would change how each paper plane would fly.
Now as an aerospace and electrical engineer, I was very excited to see this instructable contest "Make it Fly" and struggled to figure out what I should do.... and this weekend I came up with a very challenging idea. Scaling up a paper air plane that would fly.
In this Instructable, I am going to show how I took a common airplane (one of my favorites as a child) and will try to scale it up to be double in size. The following paper airplane pictured was designed by Captain R.S. Barnaby USN Retired featured in a book by Jerry Mander, George Dippel, and Howard Gossage titled 'The Great International Paper Airplane Book.'.
This paper airplane is a typical glider single-sheet paper airplane.
The goal of doubling the size of a paper airplane has several challenges and took several revisions with many failures along the way.
Supplies
Razor
Poster board
Sheets of paper 8 1/2 by 11 inches and 18 by 24 inches
A ruler
Packing tape
White glue
A pencil
Coins: pennies, nickels, dimes, quarters
First Failed Design Idea
On my first failed design I started with using a poster board due to the strength and rigidity of the foam core imbedded in the two sheets of paper.
In the following few photos you can see how I laid out using a ruler measuring double the size using the original smaller paper airplane dimensions. Using a sharp razor, I cut from the poster board the shape of the scaled up paper airplane.
Using each measurement I plotted each line and curve to the larger poster board. Remembering to scale up. If the measurement was 2 inches the large scaled up plot was 4 inches. if the wing was 5.5 inches the larger was going to be 11 inches and so on.
Using a ruler and pencil, I then marked the folds on each side and carefully used a razor to only cut through one side of the poster board. After I had obtained the angle of the fold required, I then used packing tape to seal and hold the fold. With this design, the center of gravity was not correct, so using scrap poster board I increased the air foil on the leading edge (see photo).
Even after placing more poster board, the scaled-up glider did not perform at all. I then decided to use coins (penny, dime, quarter) taped to the leading edge to provide the proper center of gravity.
This extra weight did help but not sufficiently to perform as well as the smaller paper airplane performed. Many iterations, weights, and wing configurations did not make it fly any better.
My Second Attempt
For my second attempt, I was going to use a large sheet of art paper (18" x 22"). I first cut the sheet to scale to double an 8.5" x 11" (so I cut the paper to be 17" x 22"). Using my first poster board design I was able to use the body as a template and quickly draw the curve and design of the wings on to the larger paper.
Following the instructions, I folded the larger sheet and produced the same paper airplane at twice the size (see photos). On the maiden flight, I realized there was to be a need to also have several revisions or iterations of this paper airplane.
The failures were in the lack of rigidity and strength of the winged body. It drooped and never correctly flew. After some time of thinking how I could correct the structure, I decided to add one small strip of poster board down the center of the large-scaled paper glider attached with some glue and packing tape along with a score on the center of the poster board strip (the score allows the bend/fold to be held in place after the packing tape is placed).
And much to my delight, the strengthening of the wing structure provided good center of gravity and excellent flight performance.
Thus making a larger scaled paper airplane required some fine tuning and trial after trial of flight testing, the end results was very rewarding. Persistence and resolve are something that all students, engineers, scientist and explores should have when taking on any new challenge.
Simple Glide Flights of Each Paper Airplane
After many revisions and other tests, I finally made a hybrid paper AND poster board construction paper airplane that flies really well, like the original smaller paper airplane.
The larger foam core is on the left of the two paper airplanes
You can see the videos of the small scale and larger scale paper airplane here: