What are plastic model airplanes made of

What a model airplane is made of

What is hidden in a model airplane? What electronics do you need for a model airplane to take off? In this article I would like to briefly introduce which components are required for this. We take a look at which parts are used in fixed-wing flight with an electric drive: What is the minimum required to equip a model airplane and what could also be installed?

A model airplane does not only consist of the fuselage and the wings. Before a model is ready to go into the air, a few more parts have to be installed. This includes: receiver, controller, motor, propeller, servos and, last but not least, the battery. These parts are included in every remote-controlled model airplane - with the exception that pure gliders obviously don't have an engine. In addition, a few additional things can be built into a model, such as an autopilot.


Every model airplane must be able to receive the control signals from the pilot, of course the receiver is used for this. The receivers that can be used depend on the system that the remote control is using. For example, I use two Spektrum remote controls, a DX8 and a DX6, and can therefore basically use Spektrum receivers. Alternatively, the Orange receivers from Hobbyking also work. In the picture you can see a 6-channel orange receiver and an 8-channel receiver from Spektrum. There are also many other systems such as HOTT, FASST and FrSky, to name a few. Regardless of which receiver is used, it takes on the following task: The control signals from the pilot are deciphered and passed on to the individual servos and the motor.


The controller for an electric model airplane has two tasks: On the one hand, it ensures a stable voltage supply for the controller and servos, and on the other hand, it translates the throttle position into pulses for the connected brushless motor. An important parameter is the maximum current that the motor can "draw". In the picture you can see different controllers for brushless motors, ranging from 30 amps (A) to 45 A. At the bottom of the picture you can also see a BEC (“Battery Eliminator Circuit”) - this cannot regulate a motor and only provides a stable power supply.

The controller usually has three connections: The power supply is connected directly to the battery, three strands that are connected directly to the motor and a servo cable. The receiver is supplied with power via this and the controller receives the gas signal from the receiver.


The motor drives the model airplane and is connected directly to the controller. In previous brush DC motors, a piece of graphite was used to make contact with the rotating part - the result was that over time these motors had to be serviced and the grinder had to be replaced. Today, brushless "brushless" motors are commonplace. The big advantage is that there is no maintenance; the consequence that other controllers have become necessary. The advantage outweighs by far and the brushless motors have become an indispensable part of model making. In the picture we see two brushless motors, as well as a bracket and a driver (bottom left) for the propeller.


The propeller is often referred to as a propeller and converts the rotary motion of the motor shaft into an air stream that drives the model airplane. Usually the propeller is attached directly to the motor shaft or otherwise connected to it via a gearbox. The picture shows propellers of different sizes, including two folding propellers (far left in the picture).

The most important parameters are diameter and pitch. Usually both values ​​are given in inches. A 10 x 4.7 propeller is 10 inches in diameter and 4.7 inches in pitch.


The individual control surfaces of the model airplane can be moved with the servos. Depending on how the model is constructed, different surfaces can be controlled with it, mostly: elevator, rudder and ailerons and possibly landing flaps or spoilers. You can read exactly how this works in this article.

In addition to their size, servos can also be distinguished by other important features. These include the actuating speed, which is specified in ° / sec, and the actuating force, which is measured in Ncm. In addition, it is also interesting whether the control is analog or digital and what material the gearbox is made of - metal gears are a little heavier, but much more durable than plastic gears. The example servo in the picture has an analog control and a cheaper plastic gearbox.

battery pack

The battery is absolutely necessary for flying a model airplane and it is usually not rigidly connected to the model. Instead, it can be changed as easily as possible so that you are back in the air quickly and not have to wait for the charging process. Due to the good energy-to-weight ratio and easy handling, lithium polymer batteries (LiPo) are now mainly used in model making. The most important parameter is probably the capacity, which is specified in miliampere hours (mAh). It also depends on the number of cells: Each LiPo cell has a maximum voltage of 4.2 volts - with a battery with three cells (3S), a fully charged battery has a voltage of 12.6 V. The number of cells connected in series is specified with nS, where n stands for the number.


Most model airplanes can be built and operated well with the above parts. As always, you can do “more”, such as installing a stabilizer or an autopilot. Stabilizers such as the AS3X from Spektrum are already integrated in some receivers. The autopilots offer other options, as can be seen in the picture next door: the KK board from Hobbyking and the Ardupilot.

Other ideas for components include gimbals that stabilize cameras that are carried in order to filter out the inclination of the model and vibrations. These are mainly used in multicopters.

I hope I was able to give you a little overview of the necessary electronic parts for a model airplane and I look forward to your feedback as always! Happy Landings!


Keywords:Components, model making, model flying, model airplane, tips