Radio-controlled model - AbsoluteAstronomy.com

A radio-controlled model (or RC model) is a model

Model (physical)

A physical model is a smaller or larger physical copy of an object...

Steering

Steering is the term applied to the collection of components, linkages, etc. which will allow a vessel or vehicle to follow the desired course...

with the use of 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...

. All types of vehicle

Vehicle

A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....

s imaginable have had RC systems installed in them, including car

Radio-controlled car

Radio-controlled cars are self-powered model cars or trucks that can be controlled from a distance using a specialized transmitter...

s, boat

Radio-controlled boat

- Fun Sport :Electric Sport boats are the most common type of boat amongst casual hobbyists. Hobby quality boat speed generally start at around 20MPH and go up from there, and can be just as fast or faster than their internal combustion counterparts, with the latest in Lithium Polymer and Brushless...

s, planes, and even helicopters

Radio-controlled helicopter

Radio-controlled helicopters are model aircraft which are distinct from RC airplanes because of the differences in construction, aerodynamics, and flight training...

and scale railway locomotives.

History

Radio control has been around since Nikola Tesla

Nikola Tesla

Nikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer...

demonstrated a remote control boat in 1893. World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

saw increased development in radio control technology. The Luftwaffe

Luftwaffe

Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

used controllable winged bomb

Bomb

A bomb is any of a range of explosive weapons that only rely on the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy...

s for targeting Allied

Allies of World War II

The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

ships. During the 1930s the Good brothers Bill and Walt pioneered vacuum tube

Vacuum tube

In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

based control units for R/C hobby use. Their "Guff" radio controlled plane is on display at the National Aerospace museum. Ed Lorenze published a design in Model Airplane News that was built by many hobbyists. Later, after WW2, in the late 1940s to mid 1950 many other R/C designs emerged and some were sold commercially, Berkeley's Super Aerotrol, was one such example.

Originally simple 'on-off' systems, these evolved to use complex systems of relay

Relay

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...

s to control a rubber powered escapement

Escapement

In mechanical watches and clocks, an escapement is a device that transfers energy to the timekeeping element and enables counting the number of oscillations of the timekeeping element...

's speed and direction. In another more sophisticated version developed by the Good brothers called TTPW, information was encoded by varying the signal's mark/space ratio (pulse proportional). Commercial versions of these systems quickly became available. The tuned reed system brought new sophistication, using metal reed switch

Reed switch

The reed switch is an electrical switch operated by an applied magnetic field. It was invented at Bell Telephone Laboratories in 1936 by W. B. Ellwood. It consists of a pair of contacts on ferrous metal reeds in a hermetically sealed glass envelope...

es to resonate with the transmitted signal and operate one of a number of different relays. In the 1960s the availability of transistor

Transistor

A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...

-based equipment led to the rapid development of fully proportional servo

Servomechanism

thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...

-based systems, again driven largely by amateurs but resulting in commercial products. In the 1970s, integrated circuits made the electronics small, light and cheap enough for multi-channel fully proportional control

Proportional control

A proportional control system is a type of linear feedback control system. Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor....

to become widely available.

In the 1990s miniaturised equipment became widely available, allowing radio control of the smallest models, and by the 2000s radio control was commonplace even for the control of inexpensive toys. At the same time the ingenuity of modellers has been sustained and the achievements of amateur modelers using new technologies has extended to such applications as gas-turbine powered aircraft, aerobatic helicopters and submarines.

Before radio control, many models would use simple burning fuses

Fuse (explosives)

In an explosive, pyrotechnic device or military munition, a fuse is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately...

or clockwork mechanisms to control flight or sailing times. Sometimes clockwork controllers would also control and vary direction or behaviour. Other methods included tethering to a central point (popular for model cars and hydroplanes), round the pole

Round-the-pole flying

Round-the-pole flying is a form of flying model aircraft, in which the model is attached via a line from its wingtip or fuselage to a central support structure. Control signals can be passed to the model via wires alongside or integral with the attachment line. The operator can control the...

control for electric model aircraft and control line

Control line

Control line is a simple and light way of controlling a flying model aircraft. The aircraft is connected to the operator by a pair of lines, attached to a handle, that work the elevator of the model. This allows the model to be controlled in the pitch axis...

s (called u-control

U-Control

U-Control can refer to:* "U-Control", Universal Studios own HDi Interactive Format template for the interactive technology used in HD DVD movies, later ported to the BD-J format for use in Blu-ray movies....

in the US) for internal combustion powered aircraft.

The first general use of radio control systems in models started in the late 1940s with single-channel self-built equipment; commercial equipment came soon thereafter. Initially remote control systems used escapement, (often rubber driven) mechanical actuation in the model. Commercial sets often used ground standing transmitters, long whip antennas with separate ground poles and single vacuum tube receivers. The first kits had dual tubes for more selectivity. Such early systems were invariably super regenerative circuits, which meant that two controllers used in close proximity would interfere with one another. The requirement for heavy batteries to drive tubes also meant that model boat systems were more successful than model aircraft.

The advent of transistor

Transistor

s greatly reduced the battery requirements, since the current requirements at low voltage were greatly reduced and the high voltage battery was eliminated. Low cost systems employed a superregenerative transistor receiver sensitive to a specific audio tone modulation, the latter greatly reducing interference from 27 MHz Citizens' band radio

Citizens' band radio

Citizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...

communications on nearby frequencies. Use of an output transistor further increased reliability by eliminating the sensitive output relay

Relay

, a device subject to both motor-induced vibration and stray dust contamination.

In both tube and early transistor sets the model's control surfaces were usually operated by an electromagnetic escapement controlling the stored energy in a rubber-band loop, allowing simple rudder control (right, left, and neutral) and sometimes other functions such as motor speed, and kick-up elevator.

By the early 1960s transistors had replaced the tube and electric motors driving control surfaces were more common. The first low cost "proportional" systems did not use servos, but rather employed a bidirectional motor with a proportional pulse train that consisted of two tones, pulse width modulated (TTPW). This system, and another commonly known as "Kicking Duck/Galloping Ghost", was driven with a pulse train that caused the rudder and elevator to "wag" though a small angle (not affecting flight owing to small excursions and high speed), with the average position determined by the proportions of the pulse train. A more sophisticated and unique proportional system was developed by Hershel Toomin of Electrosolids corporation called the Space Control. This benchmark system used two tones, pulse width and rate modulated to drive 4 fully proportional servos, and was manufactured and refined by Zel Ritchie, who ultimately gave the technology to the Dunhams of Orbit in 1964. The system was widely imitated, and others (Sampey, ACL, DeeBee) tried their hand at developing what was then known as analog proportional. But these early analog proportional radios were very expensive, putting them out of the reach for most modelers. Eventually, single-channel gave way to multi channel devices (at significantly higher cost) with various audio tones driving electromagnets affecting tuned resonant reeds for channel selection.

Crystal oscillator

Crystal oscillator

A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency...

superheterodyne receiver

Superheterodyne receiver

In electronics, a superheterodyne receiver uses frequency mixing or heterodyning to convert a received signal to a fixed intermediate frequency, which can be more conveniently processed than the original radio carrier frequency...

s with better selectivity and stability made control equipment more capable and at lower cost. The constantly diminishing equipment weight was crucial to ever increasing modelling applications. Superheterodyne circuits became more common, enabling several transmitters to operate closely together and enabling further rejection of interference from adjacent Citizen's Band voice radio bands.

Multi-channel developments were of particular use to aircraft which really needed a minimum of three control dimensions (yaw, pitch and motor speed), as opposed to boats which can be controlled with two or one. Radio control 'channels' were originally outputs from a reed array, in other words, a simple on-off switch. To provide a usable control signal a control surface needs to be moved in two directions, so at least two 'channels' would be needed unless a complex mechanical link could be made to provide two-directional movement from a single switch. Several of these complex links were marketed during the 1960s, including the Graupner Kinematic Orbit, Bramco, and Kraft simultaneous reed sets.

Doug Spreng is credited with developing the first "digital" pulse width feedack servo and along with Don Mathis developed and sold the first digital proportional radio called the "Digicon" followed by Bonner's Digimite, and Hoovers F&M Digital 5.

With the electronics revolution, single-signal channel circuit design became redundant and instead, radios provided coded signal streams which a servomechanism

Servomechanism

could interpret. Each of these streams replaced two of the original 'channels', and, confusingly, the signal streams began to be called 'channels'. So an old on/off 6-channel transmitter which could drive the rudder, elevator and throttle of an aircraft was replaced with a new proportional

Proportional control

A proportional control system is a type of linear feedback control system. Two classic mechanical examples are the toilet bowl float proportioning valve and the fly-ball governor....

3-channel transmitter doing the same job. Controlling all the primary controls of a powered aircraft (rudder, elevator, ailerons and throttle) was known as 'full-house' control. A glider could be 'full-house' with only three channels.

Soon a competitive marketplace emerged, bringing rapid development. By the 1970s the trend for 'full-house' proportional radio control was fully established. Typical radio control systems for radio-controlled models employ pulse width modulation (PWM), pulse position modulation (PPM) and more recently spread spectrum

Spread spectrum

Spread-spectrum techniques are methods by which a signal generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth...

technology, and actuate the various control surfaces using servomechanisms. These systems made 'proportional control' possible, where the position of the control surface in the model is proportional

Proportionality (mathematics)

In mathematics, two variable quantities are proportional if one of them is always the product of the other and a constant quantity, called the coefficient of proportionality or proportionality constant. In other words, are proportional if the ratio \tfrac yx is constant. We also say that one...

to the position of the control stick on the transmitter.

PWM is most commonly used in radio control equipment today, where transmitter controls change the width (duration) of the pulse for that channel between 920 µs

Microsecond

A microsecond is an SI unit of time equal to one millionth of a second. Its symbol is µs.A microsecond is equal to 1000 nanoseconds or 1/1000 millisecond...

and 2120 µs, 1520 µs being the center (neutral) position. The pulse is repeated in a frame of between 10 and 30 millisecond

Millisecond

A millisecond is a thousandth of a second.10 milliseconds are called a centisecond....

s in length. Off-the-shelf servos respond directly to pulse trains of this type using integrated decoder circuits, and in response they actuate a rotating arm or lever on the top of the servo. An electric motor

Electric motor

An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

and reduction gear

Gear

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....

box is used to drive the output arm and a variable component such as a resistor "potentiometer

Potentiometer

A potentiometer , informally, a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used , it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on...

" or tuning capacitor. The variable capacitor or resistor produces an error signal voltage proportional to the output position which is then compared with the position commanded by the input pulse and the motor is driven until a match is obtained. The pulse trains representing the whole set of channels is easily decoded into separate channels at the receiver using very simple circuits such as a Johnson counter

Counter

In digital logic and computing, a counter is a device which stores the number of times a particular event or process has occurred, often in relationship to a clock signal.- Electronic counters :...

. The relative simplicity of this system allows receivers to be small and light, and has been widely used since the early 1970s.
Usually a single-chip 4017 decade counter is used to decode the transmitted multiplexed PPM signal to the individual "PWM" signals sent to each RC servo.

More recently, high-end hobby

Hobby

A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...

systems using Pulse-Code Modulation

Pulse-code modulation

Pulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form for digital audio in computers and various Blu-ray, Compact Disc and DVD formats, as well as other uses such as digital telephone systems...

(PCM

Pulse-code modulation

) features have come on the market that provide a computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

ized digital

Digital

A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...

bit

Bit

A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...

-stream signal to the receiving device instead of analog type pulse modulation. Advantages include bit error checking capabilities of the data stream (good for signal integrity checking) and fail-safe

Fail-safe

A fail-safe or fail-secure device is one that, in the event of failure, responds in a way that will cause no harm, or at least a minimum of harm, to other devices or danger to personnel....

options including motor (if the model has a motor) throttle down and similar automatic actions based on signal loss. However, those systems that use pulse code modulation generally induce more lag due to lesser frames sent per second as bandwidth is needed for error checking bits. It should also be noted that PCM devices can only detect errors and thus hold the last verified position or go into failsafe mode. They cannot correct transmission errors.

In the early 21st century, 2.4 gigahertz (GHz) tramsissions have become increasingly utilised in high-end control of model vehicles and aircraft. This range of frequencies has many advantages. Because the 2.4 GHz wavelengths are so small (around 10 centimetres), the antennas on the receivers do not need to exceed 3 to 5 cm. Electromagnetic noise, for example from electric motors, is not 'seen' by 2.4 GHz receivers due to the noise's frequency (which tends to be around 10 to 150 MHz). The transmitter antenna only needs to be 10 to 20 cm long, and receiver power usage is much lower; batteries can therefore last longer. In addition, no crystals or frequency selection is required as the latter is performed automatically by the transmitter. However, the short wavelengths do not diffract as easily as the longer wavelengths of PCM/PPM, so 'line of sight' is required between the transmitting antenna and the receiver. Also, should the receiver lose power, even for a few milliseconds, or get 'swamped' by 2.4 GHz interference, it can take a few seconds for the receiver - which, in the case of 2.4 GHz, is almost invariably a digital device - to 'reboot'.

Design

RC electronics have three essential elements. The transmitter is the controller. Transmitters have control sticks, triggers, switches, and dials at the user's finger tips. The receiver

Receiver (radio)

A radio receiver converts signals from a radio antenna to a usable form. It uses electronic filters to separate a wanted radio frequency signal from all other signals, the electronic amplifier increases the level suitable for further processing, and finally recovers the desired information through...

is mounted in the model. It receives and processes the signal from the transmitter, translating it into signals that are sent to the servos. The number of servos in a model determines the number of channels

Channel (communications)

In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

the radio must provide.

Typically the transmitter multiplexes

Multiplexer

In electronics, a multiplexer is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output...

all the channels into a single pulse-position modulation

Pulse-position modulation

Pulse-position modulation is a form of signal modulation in which M message bits are encoded by transmitting a single pulse in one of 2^M possible time-shifts. This is repeated every T seconds, such that the transmitted bit rate is M/T bits per second...

radio signal. The receiver demodulates and demultiplexes the signal and translates it to the special kind of pulse-width modulation

Pulse-width modulation

Pulse-width modulation , or pulse-duration modulation , is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches....

used by standard RC servos.

In recent years, electronic speed controllers (ESCs) have been developed to replace the old variable resistors, which were extremely inefficient. They are entirely electronic, so they do not require any moving parts or servos.

In the 1980s, a Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese electronics company, Futaba

Futaba RC

is a Japanese company that is most known for designing and manufacturing hobby-grade radio control systems including transmitters, receivers, servos, electronics and model aircraft...

, copied wheeled steering for RC cars. It was originally developed by Orbit for a transmitter specially designed for Associated cars It has been widely accepted along with a trigger control for throttle

Throttle

A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases , but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which...

. Often configured for right hand users, the transmitter looks like a pistol with a wheel attached on its right side. Pulling the trigger would accelerate the car forward, while pushing it would either stop the car or cause it to go into reverse

Transmission (mechanics)

A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...

. Some models are available in left-handed versions.

Mass production

There are thousands of RC vehicles available. Most are toy

Toy

A toy is any object that can be used for play. Toys are associated commonly with children and pets. Playing with toys is often thought to be an enjoyable means of training the young for life in human society. Different materials are used to make toys enjoyable and cuddly to both young and old...

s suitable for children. What separates toy grade RC from hobby

Hobby

grade RC is the modular characteristic of the standard RC equipment. RC toys generally have simplified circuits, often with the receiver and servos incorporated into one circuit. It's almost impossible to take that particular toy circuit and transplant it into other RCs.

Hobby grade RC

Hobby grade RC systems have modular designs. Many cars, boats, and aircraft can accept equipment from different manufacturers, so it is possible to take RC equipment from a car and install it into a boat, for example.

However, moving the receiver component between aircraft and surface vehicles is illegal in most countries as radio frequency laws allocate separate bands for air and surface models. This is done for safety reasons.

Most manufacturers now offer "frequency modules" (known as crystals) that simply plug into the back of their transmitters, allowing one to change frequencies, and even bands, at will. Some of these modules are capable of "synthesizing" many different channels within their assigned band.

Hobby grade models can be fine tuned, unlike most toy grade models. For example, cars often allow toe-in

Toe (automotive)

In automotive engineering, toe, also known as tracking, is the symmetric angle that each wheel makes with the longitudinal axis of the vehicle, as a function of static geometry, and kinematic and compliant effects. This can be contrasted with steer, which is the antisymmetric angle, i.e. both...

, camber

Camber angle

thumb|100px|From the front of the car, a right wheel with a negative camber angleCamber angle is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or...

and caster angle

Caster angle

thumb|250px|θ is the caster angle, the red line is the pivot line, and the grey area is the tire.Caster angle or castor angle is the angular displacement from the vertical axis of the suspension of a steered wheel in a car, bicycle or other vehicle, measured in the longitudinal direction...

adjustments, just like their real-life counterparts. All modern "computer" radios allow each function to be adjusted over several parameters for ease in setup and adjustment of the model. Many of these transmitters are capable of "mixing" several functions at once, which is required for some models.

Many of the most popular hobby grade radios were first developed, and mass produced in Southern California by Orbit, Bonner, Kraft, Babcock, Deans, Larson, RS, S&O, and Milcott. Later, Japanese companies like Futaba, Sanwa and JR took over the market.

Aircraft

Radio-controlled aircraft (also called RC aircraft) are small aircraft

Fixed-wing aircraft

A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

that can be controlled remotely. There are many different types, ranging from small park flyers to large jets and mid-sized aerobatic models.
The aircraft use many different methods of propulsion, ranging from brushed or brushless electric motors

Electric motor

An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

, to internal combustion engines, to the most expensive gas turbine

Gas turbine

A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....

s. The fastest aircraft, dynamic slope soarers, can reach speeds of over 450 mi/h by dynamic soaring

Dynamic soaring

Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of significantly different velocity...

, repeatedly circling through the gradient of wind speeds over a ridge or slope. . Newer jets can achieve above 300 mi/h in a short distance.

Tanks

Radio-controlled tanks are replicas of armoured fighting vehicles that can move, rotate the turret and some even shoot all by using the hand-held transmitter. Radio controlled tanks come generally in commercial offerings in:

1/35th scale. Probably the best known make in this scale is by Tamiya. These can cost about $80.

1/24 scale. This scale often includes a mounted Airsoft

Airsoft

Airsoft is a sport in which participants shoot round non-metallic pellets launched via replica firearms.Gameplay varies in style and composition but often range from short-term skirmishes, organized scenarios, military simulations, historical reenactments, to competition target shooting events...

gun, the possibly the best offering is by Tokyo-Marui, but there are imitations by Heng Long, who offer cheap remakes of the tanks. The downsides to the Heng Long imitations are that they were standardized to their Type 90 tank which has 6 road wheels, then they produced a Leopard 2 and M1A2 Abrams on the same chassis but both of the tanks have 7 road wheels. These are usually the cheapest at the lowest price of around $50.

1/16 scale is the more intimidating vehicle design scale. Tamiya produce some of the best of this scale, these usually include realistic features like flashing lights, engine sounds, main gun recoil and - on their Leopard 2A6 - an optional gyro-stabilization system for the gun. These models, however command a relatively high price; with most tanks in the Tamiya range costing in excess of $700.

It should be noted that Chinese manufacturers such as (Heng Long and Matorro) have recently begun producing a variety of 1/16 tanks and other AFVs. Generally, these are much more reasonably priced, at around $150-$200, but tend to be made of inferior materials. However, a variety of after market options are available which can improve these vehicles considerably.

Both the Tamiya and the Heng Long vehicles can make use of an Infra Red battle system, which attaches a small IR "gun" and target to the tanks, allowing them to engage in direct battle.

As with cars, tanks can come from ready to run to a full assembly kit.

In more private offerings there are 1/6 and 1/4 scale vehicles available. The largest RC tank available anywhere in the world is the King tiger in 1/4 scale, over 8 feet (2.4 m) long. These GRP fiberglass tanks were originally created and produced by Alex Shlakhter (http://www.rctanks.ru/)

Cars

A radio-controlled car is a powered model car driven from a distance. Gas, nitro and electric cars exist, designed to be run both on and off-road. "Gas" cars traditionally use petrol (gasoline

Gasoline

Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

), though many hobbyists run nitro cars that use nitromethanol, a mixture of methanol

Methanol

Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...

and nitromethane

Nitromethane

Nitromethane is an organic compound with the chemical formula . It is the simplest organic nitro compound. It is a slightly viscous, highly polar liquid commonly used as a solvent in a variety of industrial applications such as in extractions, as a reaction medium, and as a cleaning solvent...

, to get their power. Building, driving, and modifying radio-controlled car kits is a hobby enjoyed by enthusiasts of all ages.

Helicopters

Radio-controlled helicopter

Helicopter

A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s, although often grouped with RC aircraft, are unique because of the differences in construction

Construction

In the fields of architecture and civil engineering, construction is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking...

, aerodynamics

Aerodynamics

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

and flight training. Several designs of RC helicopters exist, some with limited maneuverability (and thus easier to learn to fly), and those with more maneuverability (and thus harder to learn to fly).

Boats

Radio-controlled boats are model boat

Boat

A boat is a watercraft of any size designed to float or plane, to provide passage across water. Usually this water will be inland or in protected coastal areas. However, boats such as the whaleboat were designed to be operated from a ship in an offshore environment. In naval terms, a boat is a...

s controlled remotely with radio control equipment. The main types of RC boat are: scale models (12 inches (30 cm) – 144" (365 cm) in size), the sailing boat and the power boat

Motorboat

A motorboat is a boat which is powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the gearbox and the propeller in one portable unit.An inboard/outboard contains a hybrid of a...

. The latter is the more popular amongst toy grade models. Radio controlled models were used for the children's television program Theodore Tugboat
Theodore Tugboat
Theodore Tugboat is a Canadian children's television series about a tugboat named Theodore who lives in the Big Harbour with all of his friends. The show was produced in Halifax, Nova Scotia, Canada by the CBC , and the now defunct Cochran Entertainment, and was filmed on a model set using radio...

.

Out of radio-controlled model boats sprang up a new hobby—gas-powered model boating.

Radio-controlled, gasoline-powered model boats first appeared in 1962 designed by engineer Tom Perzinka of Octura Models, who is now regarded by many fellow model boaters as the 'Father of Model Boating'. The gas model boats were powered with O&R (Ohlsson and Rice) small 20 cc ignition gasoline utility engines. This was a completely new concept in the early years of available radio-control systems. The boat was called the 'White Heat' and was a hydro design, meaning it had more than one wetted surface.

Towards the late 1960s and early 1970s another gasoline-powered model was created and powered with a similar chainsaw engine. This boat was named "The Moppie" after its full-size counterpart. Again like the White Heat, between the costs of production, engine, and radio equipment, the project failed at market and perished.

By 1970, nitro (glow ignition) power became the norm for model boating.

In 1982 Tony Castronovo, a hobbyist in Fort Lauderdale, Florida, marketed the first production gasoline string trimmer engine powered (22 cc gasoline ignition engine) radio-controlled model boat in a 44-inch vee-bottom boat. It achieved a top speed of 30 miles per hour. The boat was marketed under the trade name "Enforcer" and sold by his company Warehouse Hobbies, Inc. The following years of marketing and distribution aided the spread of gasoline-powered model boating throughout the USA, Europe, Australia, and many countries around the world.

As of 2010, gasoline radio-controlled model boating has become a worldwide phenom. The industry has spawned many manufacturers and thousands of avid model boaters. Today the average gasoline powered boat can easily run at speeds over 45 mph, with the more exotic gas boats running at speeds exceeding 90 mph.

Many of Tony Castronovo's designs and innovations in gasoline model boating are the foundation upon which the industry has been built. He was first to introduce surface drive on a Vee hull (propeller hub above the water line) to model boating which he named "SPD" (surface planing drive) as well as numerous products and developments relative to gasoline powered model boating. He and his company Warehouse Hobbies Inc. continues to produce gasoline powered model boats and components at the time this article was written.

Submarines

Radio-controlled submarines can range from inexpensive toys to complex projects involving sophisticated electronics. Oceanographers and the Military also operate radio control submarines.

Combat robotics

The majority of robots used in shows such as battlebots

BattleBots

BattleBots is an American company that hosts robot competitions. BattleBots is also the name of the television show created from the competition footage. BattleBots Inc...

and Robot Wars

Robot Wars (TV series)

Robot Wars is a British game show modelled on a US-based competition of the same name. It was broadcast on BBC Two from 1998 until 2003, with its final series broadcast on Five in 2003 and 2004. Additional series were filmed for specific sectors of the global market, including two series of Robot...

are remotely controlled, relying on most of the same electronics as other radio-controlled vehicles.

Internal combustion

Internal combustion engine

The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

s for remote control models have typically been two stroke engines that run on specially blended fuel. Engine sizes are typically given in cm³ or cubic inches, ranging from tiny engines like these .02 in³ to huge 1.60 in³ or larger. For even larger sizes, many modelers turn to four stroke or gasoline engines (see below.) Glow plug engines have an ignition device that possesses a platinum wire coil in the glow plug, that catalytically glows in the presence of the methanol in glow engine fuel, providing the combustion source.

Since 1976, practical "glow" ignition four stroke

Four-stroke cycle

A four-stroke engine, also known as four-cycle, is an internal combustion engine in which the piston completes four separate strokes—intake, compression, power, and exhaust—during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle.There are two...

model engines have been available on the market, ranging in size from 3.5 cm³ upwards to 35 cm³ in single cylinder designs. Various twin and multi-cylinder glow ignition four stroke model engines are also available, echoing the appearance of full sized radial

Radial engine

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...

, inline and opposed cylinder aircraft powerplants. The multi-cylinder models can become enormous, such as the Saito five cylinder radial. They tend to be quieter in operation than two stroke engines, using smaller mufflers, and also use less fuel.

Glow engines tend to produce large amounts of oily mess due to the oil in the fuel. They are also much louder than electric motors.

Another alternative is the gasoline engine. While glow engines run on special and expensive hobby fuel, gasoline runs on the same fuel that powers cars,lawnmowers, weed whackers etc. These typically run on a two-stroke cycle, but are radically different from glow two-stroke engines. They are typically much, much larger, like the 80 cm³ Zenoah. These engines can develop several horsepower, incredible for something that can be held in the palm of the hand.

Electrical

Electric power

Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

is often the chosen form of power for aircraft, cars and boats. Electric power in aircraft in particular has become popular recently, mainly due to the popularity of park flyer

Park flyer

thumb|250px|This [[Grand Wing Servo-Tech]] [[GWS Slow Stick|Slow Stick]] is an example of an indoor/outdoor park flyerThe term park flyer denotes a class of small, primarily electric powered radio controlled aircraft, so named because their size enables some of them to be operated within the...

s and the development of technologies like brushless motors and lithium polymer batteries. These allow electric motors to produce much more power rivaling that of fuel-powered engines. It is also relatively simple to increase the torque

Torque

Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....

of an electric motor at the expense of speed, while it is much less common to do so with a fuel engine, perhaps due to its roughness. This permits a more efficient larger-diameter propeller to be used which provides more thrust at lower airspeeds. (e.g. an electric glider climbing steeply to a good thermalling altitude.)

In aircraft, cars, trucks and boats, glow and gas engines are still used even though electric power has been the most common form of power for a while. The following picture shows a typical brushless motor and speed controller used with radio controlled cars. As you can see, due to the integrated heat sink, the speed controller is almost as large as the motor itself. Due to size and weight limitations, heat sinks are not common in RC aircraft Electronic speed controller (ESCs), therefore the ESC is almost always smaller than the motor.

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.