- Estes Industries
Estes Industries (AKA Estes-Cox Corporation) is a company based in
Penrose, Colorado, USAthat designs and builds model rocketand model aircraftengines and kits. Powered by pressed black powderrocket motors, the rockets can achieve altitudes of 2500 feet.
Estes Industries was founded by
Vernon Estesin 1958, after he created "Mabel". "Mabel" was a machine designed to inexpensively manufacture model rocket engines for Model Missiles Incorporated.
Today, in addition to producing
model rocketengines, Estes offers model rocket kits for various skill levels of modelers.
1990's Estes owned North Coast Rocketrywhich served as their Mid-High Power Model Rocketry division and was discontinued in 2000.
On August 30, 2002, Barry Tunick, the Chief Executive Officer since 1991, acquired Estes-Cox Corporation from the private equity fund, TCW Capital, for the sum of $15 million.
Estes model rocket kits
Estes rocket engine 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, tumble recovery rockets, and
radio controlled gliders, they contain no delay or ejection charge.
= Estes number codingcite web|title=Estes Model Rocket Engines, Catalog Chart|url=http://www.estesrockets.com/assets/downloads/2007estescatalog.pdf?p=20] =
Each rocket engine has a code printed upon the outer jacket. This code is defined by the
National Association of Rocketry(NAR). An example of one such code is A8-3.
The capital letter (e.g., "A") indicates total
impulseproduced by the engine. Each succeeding letter represents a power range with maximum total impulse twice the impulse as the previous letter. (Example: A single "C" engine can produce anywhere from 5.01 to 10 newton-seconds of impulse, a "G" engine 80.1 to 160 newton-seconds.) Anything over a "G" engine is considered high power model rocketry.
The first number (e.g., 8) specifies that engine's average
thrustin newtons or the average push exerted by the engine. Thus a B6-0 and a C6-0 will both produce the same average thrust of 6 newtons, but the C6-0, having twice the total impulse, will fire for twice as long. The rocket engines produce maximum thrust shortly after ignition and thrust declines to a steady-state which is maintained for up to 2.5 seconds prior to burnout.cite web|title=Estes Model Rocket Engines, Time/Thrust Curves|url=http://www.estesrockets.com/assets/downloads/2007estescatalog.pdf?p=21]
The final number (e.g., 3) indicates the delay between the thrust and the ejection charge, in
seconds. Engines with a delay of zero are typically used as booster engines in multi-stage rockets and there is no ejection charge. In this case, the burning propellent ruptures through the top and hot bits of propellent enter the nozzle of the upper stage engine, thus igniting that engine and forcing the booster assembly away, usually to tumble safely to earth.
Estes engine construction
The engines are constructed within a sturdy cardboard tube. Inside are placed a ceramic nozzle, solid propellant, delay charge, ejection charge, and a clay retainer cap.
The solid propellant is ignited by a coated wire inserted through the nozzle and in contact with the propellant. An electric current heats the wire and ignites the solid propellant. An engine can also be ignited by the hot bits of propellant from a booster engine.
* [http://www.estesrockets.com Estes Industries]
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