Estes Industries is a company based in Penrose, Colorado, USA who design and build model rocket and model aircraft engines and kits. Powered by compressed black powder capsules, the rockets can achieve altitudes of 2500 feet.

Estes produces several types of engines, each with different specifications.

Estes color coding

Estes engines are color-coded for recommended use. GREEN engines are for use in single stage models; PURPLE engines for the top stages of multi-stage rockets and very light single stage rockets; RED engines for all booster and intermediate states of multi-stage models. BLUE are “plugged” and are used for rocket powered racers and radio controlled gliders, they contain no delay or ejection charge.

Estes number coding

Each rocket has a code printed upon the outer jacket. A typical coding might be A8-3.

The capital letter (A) indicates total impulse or total power produced by the engine. Each succeeding letter has twice the impulse as the previous letter. (Example: "B" engines have twice the power of "A" engines). Estes produces 1/4 A, 1/2 A, A, B, C, D, and E engines. Other model rocket companies produce F and G engines. A single C engine can produce 10 newton-seconds of impulse, a G engine 160 newton-seconds.

The first number (8) shows that engine's average thrust in newtons or the average push exerted by the engine.

The second number (3) indicates the delay between the thrust and the ejection charge. This rocket has a delay of three seconds. Engines with a delay of zero are used as booster engines, where the ejection charge ignites the next engine.

Estes engine construction

The engines are constructed inside a sturdy, cardboard tube. Inside are placed a ceramic nozzle, solid propellant, delay charge, ejection charge, and a clay retainer cap, respectively.

The solid propellant is ignited by a coated wire inserted into the nozzle as to come in contact with the propellant. When electricity is applied to the wire, the wire heats to the point of combustion, thereby detonating the solid propellant. A engine can also be ingnited by the ejection charge of a booster engine.

External links

• Estes Industries homepage (http://www.estesrockets.com/)