Air Plane Photos 2013: Model Airplanes Kits

Model Airplanes Kits

Source(www.google.com.pk)

All internal combustion engines generate substantial noise (and engine exhaust) and require routine maintenance. In the 'scale-R/C' community, glow-engines have long been the mainstay until recently.

For larger and heavier models, the most popular powerplant is the glow engine. Glow engines are fueled by a mixture of slow burning methanol, nitromethane, and lubricant (castor oil or synthetic oil, which is sold pre-mixed as glow-fuel). Glow-engines require an external starting mechanism; the glow plug must be electrically heated until its temperature can trigger fuel-ignition, upon which the engine's combustion-cycle becomes self-sustaining. The reciprocating action of the cylinders applies torque to a rotating crankshaft, which is the engine's primary power-output. (Some power is lost in the form of waste-heat.)

Model Aircraft Engines

Vendors of model engines rate size in terms of engine displacement. Common sizes range from as small as 0.01 cubic inch (in3) to over 1.0 in3 (0.16 cc–16 cc). Under ideal conditions, the smallest .01 engines can turn a 3.5" (9 cm) propeller at speeds over 30,000 rpm, while the typical larger (.40-.60 cubic inch) engine will turn at 10–14,000 rpm.

The simplest glow-engines operate on the two-stroke cycle. These engines are inexpensive, yet offer the highest power-to-weight ratio of all glow-engines. Glow engines which operate on the four-stroke cycle, whether using ordinary poppet valves or occasionally rotary valves offer superior fuel-efficiency (power-output per fuel-consumption), but deliver less power than two-stroke engines of the same displacement – yet, often because the power they deliver is more suited to turning somewhat larger diameter propellers for lighter weight, more drag-producing airframe designs such as biplanes and scale aircraft models of pre-World War II full-scale subjects, four-stroke model engines, fueled either with methanol or gasoline fuels are slowly increasing in popularity from their generally lower noise output.

A very large "giant scale" US Coast Guard C-130J Hercules radio control flying model. The wingspan is 18 feet 6 inches (5.6 m). The crew of five who fly and maintain it are in the background.

Internal combustion (IC) engines are also available in upscale (and up-price) configurations. Variations include engines with multiple-cylinders, spark-ignited gasoline operation, and carbureted diesel operation. Diesel-combustion operates by compression-ignition. The compression-ratio is controlled by an adjustable threaded T screw on the cylinder head, bearing onto a contra piston within the cylinder bore. Diesels are preferred for endurance competition, because of their fuel's higher energy content, a mixture of ether and kerosene (with lubricating oil).

Early "jet" style model aircraft utilized a multi-blade and high pitched propeller (fan) inside ductwork, usually in the fuselage of the aeroplane. The fans were generally powered by 2 stroke piston engines that were designed to operate at high RPM. Early brands of these units were the Kress, Scozzi, and Turbax, among others. They generally used 0.40 to 0.90 cubic inch displacement engines, but Kress made a model for engines as small as 0.049 (1/2cc). This basic fan-in-tube design has been adopted very successfully for modern electric powered "jet" aircraft and are now quite popular. Glow engine powered ducted-fan aircraft are now relatively uncommon

A major development is the use of small jet turbine engines in hobbyist models, both surface and air. Model-scale turbines resemble simplified versions of turbojet engines found on commercial aircraft, but are in fact new designs (not based upon scaled-down commercial jet engines.) The first hobbyist-developed turbine was developed and flown in the 1980s by Gerald Jackman in England, but only recently has commercial production (from companies such as Evojet in Germany) made turbines readily available for purchase. Turbines require specialized design and precision-manufacturing techniques (some designs for model aircraft have been built from recycled turbocharger units from car engines), and consume a mixture of A1 jet fuel and synthetic turbine engine or motorcycle-engine oil. These qualities, and the turbine's high-thrust output, makes owning and operating a turbine-powered aircraft prohibitively expensive for most hobbyists, as well as many nations' national aeromodeling clubs (as with the USA's AMA) requiring their users to be certified to know how to safely and properly operate the engines they intend to use for such a model.[11] Jet-powered models attract large crowds at organized events; their authentic sound and high speed make for excellent crowd pleasers.