Editing Radio-controlled model (section)

== Power ==

=== Internal combustion ===
[[Internal combustion engine]]s for remote control models have typically been [[two stroke]] engines that run on specially blended fuel. Engine sizes are typically given in cm<sup>3</sup> or cubic inches, ranging from tiny engines like these .02 in<sup>3</sup> to huge 1.60 in<sup>3</sup> 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 cycle|four stroke]] model engines have been available on the market, ranging in size from 3.5&nbsp;cm<sup>3</sup> upwards to 35&nbsp;cm<sup>3</sup> 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 engine|radial]], inline and opposed cylinder aircraft powerplants. The multi-cylinder models can become enormous, such as the [[Saito (sompany)|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&nbsp;cm<sup>3</sup> Zenoah. These engines can develop several horsepower, incredible for something that can be held in the palm of the hand.

=== Electrical ===
[[Electric power]] 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]]s and the development of technologies like [[brushless motor]]s and [[lithium polymer battery|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]] 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.