This was an idea that came to me when I had a box cutter in one hand, and a coffee cup on the other, and I literally made it in 2 minutes. It's a quick and easy way that is good for entertaining kids (and adults too, sometimes)
Of course, it wasn't very symmetrical, and it didn't fly in a steady way, so I made another (this took about 10 minutes total, if you exclude the time I took to take the photos), and I took videos of it.
Step 1: Marking the Circle
First I made the outline (of the top of the cup) on a piece of paper, and then I folded the paper in half, and then folded in half again to make into a quarter.
I then divided the quarter circle approximately into thirds. This I then used to make 12 markings on the cup.
The same was repeated for the bottom of the cup. (Pictures not included)
Step 2: Drawing the Lines
This one is fairly self explanatory. I used a felt pen to mark straight lines from the top to the bottom of the cup
Step 3: Cutting Along the Lines
I used a utility knife. The blades, being thin, do not distort the card too much while it is being cut.
After cutting along all 12 lines, I alternately cut along the top of the card to make the 'blades'
Step 4: Folding Back
After making the alternating cuts at the wider end of the cup, fold back the 'blades' at the base of the cup until it's level with the base.
Step 5: Launching It
My first attempts at launching. They weren't upto par, as I discovered a few days after I took the video, since I found I could make it move about 10 feet forward by giving it a forward push.
A sharp twist of the wrist, while throwing it upwards is usually enough. Feel free to try other methods.
To see if it could be launched bottom up, I found that it worked quite well.
And of course, the control.
To prove that this design actually converts a coffee cup into a flying object, I tried using the same hand motion on an uncut coffee cup
Step 6: Possible Modifications
Runner Up in the
Coffee Cup Challenge