Estes Industries
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Estes Industries (AKA Estes-Cox Corporation) is a company based in Penrose, Colorado, USA that designs and builds model rocket and model aircraft engines and kits. Powered by compressed black powder capsules, the rockets can achieve altitudes of 2500 feet.
Estes Industries was founded by Vernon Estes in 1958, after he created the MABEL. The MABEL was a machine designed to inexpensively manufacture model rocket engines for the then Model Missile company.
Today, in addition to producing model rocket engines, Estes offers model rocket kits for various skill levels of modelers.
Throughout the 1990's Estes owned North Coast Rocketry which 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.
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[edit] Estes model rocket kits
[edit] 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 and radio controlled gliders, they contain no delay or ejection charge.
[edit] Estes number coding[1]
| Type | Total Impulse (Newton seconds) |
|---|---|
| ¼A | 0.31-0.62 |
| ½A | 0.63-1.25 |
| A | 1.26-2.50 |
| B | 2.51-5.00 |
| C | 5.01-10.00 |
| D | 10.01-20.00 |
| E | 20.01-30.00 |
Each rocket engine has a code printed upon the outer jacket. An example of one such code is A8-3.
The capital letter (e.g., A) indicates total impulse produced 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 thrust in 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.[2]
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.
[edit] 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.
[edit] Notes
[edit] External links
