Rocket motors range from A through to M with A being the weakest and M being the strongest. Estes and Quest use A - C motors as well as a few rockets that fly on D's. Aerotech use motors D - M. For the D - M motors you need to get a license to buy and use them. This license is easy to get if you follow the instructions on how to get it. For the license details click here.

There is one exception to all this which is miniature engines. These are much smaller than normal engines and have less power. These are used to fly rockets such as the Rogue Gnat.

Estes Half "A" motor	Estes "B" motor	An Aerotech "E" motor
Aerotech "F" motor		Aerotech "G" motor

The letter and numbers on the motor gives you information about the motor. Lets take the "B6-4" motor for an example. The "B" represents the total impulse of that motor. Impulse letters for Estes model rockets stop at D, other companies go up to "N" or bigger! The "6" number tells you the average thrust, measured in Newtons. Finally, the "4" number stands for the time delay of the ejection charge, the time between the motor finishing and the ejection charge going. An motor with a zero at the end means that there is no ejection charge. These motors are for booster stage in a multi-staged rocket. All commercially made motors have this classification.

Estes are the biggest manufacturers of low power rocket motors. While Aerotech rule the mid and high power range. Although there are a few other smaller companies like Apogee who also make motors. You should NEVER attempt to make your own motors, this is highly illegal and will most probably end in injury to yourself and others.

Here is a table of most of the engines that you can buy. Obviously there are so many some may be missing. Please let me know if you know of any that are not here.

After the Aerotech motors there is a letter this denotes the type of propellant. These are :

W - White lightning = White smoke, load cackling roar.

T - Blue Thunder = Little smoke, blue flame, fast burning.

J - Black Jack = Black smoke, thunderous roar.

Some Aerotech engines do not have a number at the end these are ones which must have electronic ejection charges with an altimeter and some black powder. They start off with the least powerful and end with the most powerful.