| There are many different factors that help to | | | | on it. Cut the profile out and balance it on the edge of |
| determine the flight capabilities of model rockets. For a | | | | the ruler. This will give you the rough center of |
| model rocket to be considered stable it must be able | | | | pressure. |
| to resist the drag coefficient in order to reach its | | | | Mark the balance point on the cardboard profile and |
| maximum altitude while in flight. If a model rocket is | | | | you will then be able to make any adjustments |
| unstable there is the chance of serious injury occurring. | | | | necessary. The next step is to try a string test out on |
| You should always find out roughly how stable your | | | | the model rocket itself. Tie the string around the center |
| model will be before launching it. | | | | of gravity and then you can swing the model around in |
| There are a few different ways that you can do this. | | | | circles making certain not to let it go. If you have |
| One method involves using the center of gravity and | | | | properly found the CG then the rocket will point into |
| center of pressure. There are a few things you will | | | | the direction you are swinging it rather than having a |
| need to gather to be able to figure these. You will | | | | wobbling motion. |
| need some scissors, a pencil, a ruler, some string and a | | | | By roughly calculating the CG and CP in this method |
| piece of cardboard. The first step will be to locate | | | | you can then begin to adjust your rocket design to |
| your rocket's center of gravity. The center of gravity | | | | lessen or change these values for a longer, shorter, |
| is the specific point that your rocket rotates around. | | | | higher or lower flight time or path. For those that have |
| To find this you will need to tie the string around the | | | | a love of high mathematics, there is a way to calculate |
| middle of the rocket. You can then begin to move the | | | | the CP much more accurately called the Barrowman |
| string back and forth until you find the point at which it | | | | Method. This method involves a great deal of |
| is able to balance horizontally. Once you find this point | | | | computations but this can be offset by finding |
| you should make a note of it. Next you will find the | | | | spreadsheet templates online that are free and will |
| center of pressure. This is the point on the rocket that | | | | calculate the CP for you with just a few inputs on your |
| is affected the most by air pressure or drag. Take the | | | | part. |
| piece of cardboard and trace the profile of the rocket | | | | |