Estes Industries
Encyclopedia
Estes Industries is a company based in Penrose, Colorado
, USA that designs and builds model rocket
and model aircraft
engines and kits. They were the best known model rocket company during the "golden age of rocketry" in the 1970s and early 1980s, competing primarily with Centuri Engineering and a host of smaller firms like Canaroc and Flight Systems, Inc. In the 1990s the hobby had almost disappeared, and Estes bought Centuri, folding their product lines together. Throughout the 1990s Estes owned North Coast Rocketry
(NCR), which served as their mid-power and high-power rocketry division, although Estes discontinued the NCR line in 2000. Today, in addition to producing model rocket
engines, Estes offers model rocket kits for various skill levels of modelers, as well as remote control airplanes. Several independent sources have published measurements showing that Estes model rocket engines often fail to meet their published thrust specifications.
in 1958, after he created "Mabel". "Mabel" was a machine designed to inexpensively manufacture model rocket engines for Model Missiles Incorporated. At some point, Vernon Estes sold Estes Industries. Then, on August 30, 2002, Barry Tunick, who had been the Chief Executive Officer
since 1991, acquired Estes-Cox Corporation from the private equity fund, TCW Capital, for the sum of $15 million. On January 15, 2010, Estes-Cox was acquired by Hobbico
, Inc.
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Estes produced a wide variety of rocket model kits, normally using paperboard
tubing for the fuselage
and balsa wood for fins and nose cone
s. Early models tended to be relatively simple in design terms, differing in terms of size, number of stages and recovery method. One particularly well-known design from this era was the Camroc, a small camera that replaced the nose cone of larger models that was designed to take a single image on a small disk of film when the motor had burned out and the rocket was facing downward. The Cineroc used a small movie camera that could be launched from larger rockets, taking a series of frames as the rocket ascended.
Later model kits from the late 1970s and early 1980s tended to be more for show than performance, including a series of scale or sport-scale designs and "exotics". Centuri was also well known for these sorts of designs, and the two companies often copied design elements from the other's latest models. The downturn in the hobby in the later 1980s led to consolidation
of the two companies. During the 1990s the model line was dramatically reduced, and the ones that were left were typically very simple "three fins and a nose cone" designs that were partially or entirely completed.
Estes engines are color-coded for recommended use. GREEN engines are for use in single-stage models; PURPLE engines for the top stages of multistage rocket
s 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, aerobrake recovery rockets, and radio control
led gliders
, they contain no delay
or ejection charge
. BLACK has been used in the past for static test engines, which were also plugged to prevent blow-through.
It can be dangerous to use upper-stage engines in normal single-stage rockets. The large delay in ejection can be problematic. The rocket may already be halfway through its descent when the nose comes off and the rocket may not be slowed down enough before it hits the ground.
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 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.
The final number (e.g., 3) indicates the delay between the thrust and the ejection charge, in second
s. 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.
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 gases from the propellant of a booster engine.
Penrose, Colorado
Penrose is a census-designated place in Fremont County, Colorado, United States. The population was 4,070 at the 2000 census. The Penrose Post Office has the ZIP Code 81240.-Geography:Penrose is located at ....
, USA that designs and builds model rocket
Model rocket
A model rocket is a small rocket that is commonly advertised as being able to be launched by anybody, to, in general, low altitudes and recovered by a variety of means....
and model aircraft
Model aircraft
Model aircraft are flying or non-flying models of existing or imaginary aircraft using a variety of materials including plastic, diecast metal, polystyrene, balsa wood, foam and fibreglass...
engines and kits. They were the best known model rocket company during the "golden age of rocketry" in the 1970s and early 1980s, competing primarily with Centuri Engineering and a host of smaller firms like Canaroc and Flight Systems, Inc. In the 1990s the hobby had almost disappeared, and Estes bought Centuri, folding their product lines together. Throughout the 1990s Estes owned North Coast Rocketry
North Coast Rocketry
North Coast Rocketry was a model rocket company founded in Ohio by Chris Pearson and Matt Steele, with Dan Kafun added as a partner in 1989.-History:...
(NCR), which served as their mid-power and high-power rocketry division, although Estes discontinued the NCR line in 2000. Today, in addition to producing model rocket
Model rocket
A model rocket is a small rocket that is commonly advertised as being able to be launched by anybody, to, in general, low altitudes and recovered by a variety of means....
engines, Estes offers model rocket kits for various skill levels of modelers, as well as remote control airplanes. Several independent sources have published measurements showing that Estes model rocket engines often fail to meet their published thrust specifications.
History
Estes Industries was founded by Vernon EstesVernon Estes
Vernon Estes , born January 4, 1930, is the founder and namesake of Estes Industries, the highly-recognized model rocket production company, headquartered in Penrose, Colorado....
in 1958, after he created "Mabel". "Mabel" was a machine designed to inexpensively manufacture model rocket engines for Model Missiles Incorporated. At some point, Vernon Estes sold Estes Industries. Then, on August 30, 2002, Barry Tunick, who had been the Chief Executive Officer
Chief executive officer
A chief executive officer , managing director , Executive Director for non-profit organizations, or chief executive is the highest-ranking corporate officer or administrator in charge of total management of an organization...
since 1991, acquired Estes-Cox Corporation from the private equity fund, TCW Capital, for the sum of $15 million. On January 15, 2010, Estes-Cox was acquired by Hobbico
Hobbico
Hobbico, Inc. is located in Champaign, Illinois and is a manufacturer and distributor of hobby products including radio control airplanes, boats, cars and helicopters. Other products include plastic model kits, model rockets, model trains, slot cars, crafts, jigsaw puzzles and games...
, Inc.
Estes rockets
Paperboard
Paperboard is a thick paper based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper. According to ISO standards, paperboard is a paper with a basis weight above 224 g/m2, but there are exceptions. Paperboard can be single...
tubing for the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
and balsa wood for fins and nose cone
Nose cone
The term nose cone is used to refer to the forwardmost section of a rocket, guided missile or aircraft. The cone is shaped to offer minimum aerodynamic resistance...
s. Early models tended to be relatively simple in design terms, differing in terms of size, number of stages and recovery method. One particularly well-known design from this era was the Camroc, a small camera that replaced the nose cone of larger models that was designed to take a single image on a small disk of film when the motor had burned out and the rocket was facing downward. The Cineroc used a small movie camera that could be launched from larger rockets, taking a series of frames as the rocket ascended.
Later model kits from the late 1970s and early 1980s tended to be more for show than performance, including a series of scale or sport-scale designs and "exotics". Centuri was also well known for these sorts of designs, and the two companies often copied design elements from the other's latest models. The downturn in the hobby in the later 1980s led to consolidation
Consolidation (business)
Consolidation or amalgamation is the act of merging many things into one. In business, it often refers to the mergers and acquisitions of many smaller companies into much larger ones. In the context of financial accounting, consolidation refers to the aggregation of financial statements of a group...
of the two companies. During the 1990s the model line was dramatically reduced, and the ones that were left were typically very simple "three fins and a nose cone" designs that were partially or entirely completed.
Estes rocket engine color coding
Multistage rocket
A multistage rocket is a rocket that usestwo or more stages, each of which contains its own engines and propellant. A tandem or serial stage is mounted on top of another stage; a parallel stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or...
s and very light single-stage rockets; RED engines for all booster
Booster rocket
A booster rocket is either the first stage of a multi-stage launch vehicle, or else a strap-on rocket used to augment the core launch vehicle's takeoff thrust and payload capability. Boosters are generally necessary to launch spacecraft into Earth orbit or beyond...
and intermediate states of multi-stage models. BLUE are “plugged” and are used for rocket-powered racers, aerobrake recovery rockets, and radio control
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...
led gliders
Glider aircraft
Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine. Mostly these types of aircraft are intended for routine operation without engines, though engine failure can...
, they contain no delay
Delay composition
Delay composition, also called delay charge or delay train, is a pyrotechnic composition, a sort of pyrotechnic initiator, a mixture of oxidizer and fuel that burns in a slow, constant rate that should not be significantly dependent on temperature and pressure. Delay compositions are used to...
or ejection charge
Ejection charge
Ejection charge, also called expelling charge, is a pyrotechnic composition, a type of a pyrotechnic gas generator designed to produce a small short-term amount of thrust to burst open a container and eject its content....
. BLACK has been used in the past for static test engines, which were also plugged to prevent blow-through.
It can be dangerous to use upper-stage engines in normal single-stage rockets. The large delay in ejection can be problematic. The rocket may already be halfway through its descent when the nose comes off and the rocket may not be slowed down enough before it hits the ground.
Estes number coding
| 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 | 20.01-40.00 |
Each rocket engine has a code printed upon the outer jacket. This code is defined by the National Association of Rocketry
National Association of Rocketry
The National Association of Rocketry is the governing body for the sport/hobby of model rocketry in the United States. It was established in 1957 by Orville Carlisle and G. Harry Stine and is currently headed by Trip Barber. It is the oldest and largest model rocketry governing body in the...
(NAR). 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
High powered rocket
High-power rocketry is a hobby similar to model rocketry. The major difference is that higher impulse range motors are used. The National Fire Protection Association definition of a high-power rocket is one that has a total weight of more than 1500 grams and contains a motor or motors...
model rocketry.
The first number (e.g., 8) specifies that engine's average thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....
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.
The final number (e.g., 3) indicates the delay between the thrust and the ejection charge, in second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
s. 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 ceramicCeramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...
nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....
, solid propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
, delay charge, ejection charge
Ejection charge
Ejection charge, also called expelling charge, is a pyrotechnic composition, a type of a pyrotechnic gas generator designed to produce a small short-term amount of thrust to burst open a container and eject its content....
, and a clay retainer cap.
The solid propellant is ignited by a coated wire
Electric match
An electric match is a device that uses an externally applied electric current to ignite a combustible compound.-Use:Electric matches can be used in any application where source of heat is needed at a precisely controlled point in time, typically to ignite a propellant or explosive...
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 gases from the propellant of a booster engine.