Comparison Syma S107C vs WL Toys V922

The minimum age for which this radio-controlled model is suitable. These recommendations are rather conditional, but it is still not recommended to deviate from them. "Adult" models 14+ with many adjustments, moving parts and power simply will not be able to master the baby. At the same time, models for the younger age category may not be interesting and boring for older children.

Helicopter rotor(s) diameter. In fact, this parameter primarily determines the dimensions of the machine in the working position; this is especially true for three- and four-bladed models, where the propeller cannot be deployed along the fuselage, reducing the width of the space occupied (although the blades can be folded, which eliminates this drawback). Otherwise, the diameter of the rotor is of secondary importance: it is selected by the manufacturer in such a way as to provide features corresponding to the class of the machine, and it is worth focus primarily on the general purpose and price category of the helicopter, and not the size of the propeller.

The diameter of the tail rotor in machines of the classical scheme (see below). This parameter is of practical importance only in professional aircraft modeling sports, and even then quite rarely; relevant moments are described in special sources.

The layout of the propellers used in the design of the helicopter.

— Classic. This scheme assumes the presence of one main rotor on the main axis and a small tail rotor on the tail. The tail rotor compensates for the torque from the carrier (without such compensation, the helicopter would turn in the direction opposite to the rotation of the main rotor), and is also responsible for course control — turns left and right are carried out precisely by changing the tail rotor thrust. Helicopters of the classical scheme are more complicated and more expensive than coaxial ones, and are also more demanding on control accuracy; on the other hand, they have more manoeuvrability and are better suited for aerobatics, including complex. Therefore, this design is typical mainly for advanced devices of semi-professional and professional class.

— Coaxial. The name of this scheme is due to the fact that such helicopters have two rotors located on the same axis, one above the other. The propellers rotate in opposite directions, which makes it possible to dispense with the tail rotor and use all the engine power to create vertical thrust. However, in most cases there is a small screw on the tail — but, unlike the classical scheme, it provides control of the helicopter in pitch, and not in the course, and does not rotate constantly, but only if necessary, tilt the car forward or backward. Coaxial circuit...models are much cheaper and easier to manage than classical ones, but the freedom of manoeuvre in them is limited. Therefore, this option is considered optimal for novice users, as well as amateurs who do not claim to be professional pilots.

The number of blades provided in the design of the main rotor of a helicopter. When calculating this number, all rotors are taken into account — this means that in the coaxial circuit models (see above), the total number for both screws is indicated. Actually, in such machines 4 blades are used as standard — 2 per screw, there is usually no need for more; but in the classical scheme, this number can be different — from 2 to 3 — 8(technically, more is possible, but in fact this is rare).

The fewer blades provided in the design, the simpler and cheaper the screw (ceteris paribus), but the faster it must rotate in order to provide the necessary lift; this puts forward corresponding requirements to the engine. However, the number of blades is usually chosen by the manufacturer in such a way as to provide the machine with flight characteristics corresponding to the price and class. Therefore, this parameter can only be of practical importance for professional models designed for complex aerobatics; You can read more about this in special sources.

The presence in the design of the helicopter of a stabilization system in the form of a so-called servo axis (flybar) located on the axis of the main rotor (above it or below it). A spun flybar tends to keep the plane of rotation in one position, thus ensuring a stable position for the entire helicopter. This has a positive effect not only on resistance to wind gusts, but also on the quality of control: without a flybar, the helicopter would react too sharply to commands from the remote control, and with a stabilizer, control becomes soft, smooth and accessible even to beginners. On the other hand, the higher the stability, the lower the accuracy and responsiveness of the control; therefore, in professional flight machines, a flybar may be absent — its role in such cases is played by an electronic stabilization system.

The capacity of the battery supplied with the electric motor model (see "Motor"). Indicated only for variants using branded batteries (see "Battery type"), measured in ampere-hours: 1 Ah corresponds to the capacity at which the battery is capable of delivering a current of 1 A for 1 hour.

The higher the battery capacity, the more time the helicopter can spend in the air, usually. However, the practical time of operation on a charge is largely determined by other characteristics of the machine — dimensions and weight, engine model and power, etc. Therefore, in most cases, this parameter plays a purely reference role, and only helicopters that do not have any significant differences in other characteristics (and even then very approximately) can only be compared in terms of battery capacity.

Model of the original battery (see “Battery type”) for which the helicopter is designed. Most often, such a battery is supplied with the device. Data on the battery model may be needed if it is out of order and needs to be replaced, when looking for a spare battery or when selecting a charger (usually, charging capabilities are already provided in the standard package, but it is possible that a separate device will be required).

Operating time of an electric powered helicopter (see "Engine") on one battery charge or on one set of batteries. This parameter is rather conditional and approximate: it is usually indicated for optimal operating conditions, with a uniform low load on the engine (most often for hover mode), and when using replaceable cells — for high quality batteries. Accordingly, in fact, the operating time may differ markedly from that stated in the specifications. Nevertheless, this indicator quite reliably describes the battery life of the car, and different models can be compared according to it.