This week’s project was to take a piece of styrofoam and make it fly through the air. This is a fun and simple way to learn a little about aeronautics.
- Styrofoam rectangle (you can use a meat tray)
- Playing card
- Exacto Knife
Make a styrofoam rectangle. I used a meat tray from the supermarket; wash off all of the salmonella and cut off the rounded sides to create a flat piece.
Center of Gravity:
For an object to fly, the center of gravity (CG) needs to be 75% behind the balancing point. Right now the balancing point is in the center of the rectangle. What we need to do is divide up the rectangle into quarters. Measure from the front to back of the rectangle, take that number and divide it by 4. Then measure from the front of the rectangle that measurement and draw a line across. This will give us the mark where the center of gravity needs to be. Next we are going to use coins to balance our styrofoam. Start with a quarter, tape it onto the front edge in the center. Then hold your styrofoam, very lightly, at the 25% line you just drew. Does it balance? If not then add more change, 1 coin at a time, until it balances. This will give us the CG needed to make the styrofoam stay up.
Next we will add what is called “reflex.” To do this we will measure 1” from the back of the rectangle, and draw a line across. We should also make a mark in the center at the back as well for the next step. Now we will slightly fold up the back edge along the 1” line. Don’t bend too much or too high, you could break the styrofoam, you just need a slight bend.
Reflex will help keep the nose (front) of the glider in the air. As your glider flies through the air, air pressure will force the front tip down. Reflex will help keep the nose up so that the glider flies farther.
The last step is to add balance. This will help your glider dip flat, and not sway left or right. It will also help it fly straighter. To do this we are going to cut a small slit at the back of the rectangle with our exacto knife. You are going to cut along the center of the styrofoam at the mark you made in the previous step. Then take a playing card or business card and stick it into the slit. Check the reflex now. It will likely be uneven after you cut this. Once it is equal you are ready to fly.
Make a quick check to make sure the CG is still at the 25% mark. Sometimes this will change as you are working on the glider. If it isn’t, add or remove coins.
Let It Fly:
Find a space like a long corridor. Since this is made out of styrofoam it is very safe to fly. Hold the glider at the CG (the line you made in step 1. Hold it over your head. Now, this is the most difficult and important part: you must hold the glider parallel to the ground, don’t point the front up or down, and throw it like a soccer ball keeping it parallel. It may take a few tries to get this right. Now see how far you can get it to fly through the air.
Want to learn more about aeronautics? Check out Brooklyn Aerodrome. They love to make stuff fly, and came up with this project. They have great resources and kits to learn all about aeronautics.