Comparison Vlastelin Nebes Osa vs Syma S109G

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.

A method of transmitting torque to the tail rotor of a helicopter. Note that such a screw can also be used in coaxial machines (see above).

— Val. Transfer of rotation from the main engine using a shaft located inside the tail boom. This option is very convenient for those cases when the screw needs to be rotated constantly, but is not suitable for periodic inclusions. Therefore, it is found only among models of the classical scheme. The main advantage of this type of drive is considered to be high precision in control, however, it is also quite expensive.

— Belt. As the name implies, the link between the tail rotor and the engine in this case is provided by a belt drive. Like the shaft described above, this option is used in classic helicopters; it is less precise in control, but is also suitable for aerobatic models. Of the obvious disadvantages, one can note the need for periodic adjustment of the belt tension — in order to avoid slippage.

— Motor. In such models, a separate miniature motor is provided to rotate the tail rotor. This option is very convenient for coaxial helicopters, where the tail rotor is switched on periodically for pitch control; however, it can also be used in classic models (usually low-cost level). The motor is cheaper than the rotor and belt, and the design of the machine itself is simpler; control accuracy, however, is usually low, however,...given the class of machines where such a drive is used, this disadvantage can hardly be called critical.

— Missing. The complete lack of tail rotor drive is found in low-cost coaxial models; the screw itself, however, may be present — as a decorative dummy.

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.

Operating voltage of the battery supplied with the helicopter. For models for AA cells (see "Battery type"), this voltage is not indicated — the specification of such cells assumes a common voltage standard, about 1.5 V. In other cases, this data is not particularly important for everyday use, but it may be useful if you you need to pick up a charger, a spare battery or a battery to replace a damaged one, but you don’t have data on the battery model (see below).

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.

The frequency at which the helicopter control transmitter operates.

— 27.145 MHz. One of the frequencies used for radio remote control for a long time; in some CIS countries it is even reserved by state regulatory bodies for this very purpose. Such transmitters are relatively inexpensive, but suffer from one serious drawback: they do not provide channel separation when several consoles are operating in close proximity to each other. In other words, if the helicopter stays in the coverage area of two transmitters, the signals from them will be mixed, which is actually equivalent to a loss of control. This is most often unimportant in "recreational" flights; however, at competitions and other public events where several cars can be in the flight zone at the same time, very unpleasant and even dangerous situations can arise. You can avoid such situations by developing a common frequency grid and using interchangeable crystal oscillators for consoles — but such features are not always available. As a result, this frequency is gradually being replaced by the more advanced 2.4 GHz standard, not only among professional, but also among amateur models.

Separately, we note that transmitters with frequencies of 35, 40 and 75 MHz can also be found on the market; according to the main features, they are completely similar to the described 27.145 MHz and differ only in the operating frequency.

— 2.4 GHz. Today's most advanced communication standard used by remote control helicopters. Its main feature (and difference from the above options) is the possibility of normal operation of several transmitters of this format in close proximity to each other. To do this, various technologies are used that provide automatic distribution of receiver-transmitter pairs over their own channels (similar to how it happens, for example, in mobile communications). Theoretically, the 2.4 GHz band may be more prone to interference, as many modern electronics work in it (in particular, Wi-Fi and Bluetooth modules); however, thanks to the distribution of channels mentioned, such problems arise only in very unfortunate cases, but are solved easily and quickly. In addition, due to the coincidence in frequencies with the Wi-Fi standard, models for such remotes can be easily controlled from a smartphone (see below).

The frame is the base of the helicopter; it is on it that the engine, mechanisms, electronics and body are installed. It may have the following structure:

— Team. This category includes frames consisting of separate parts on detachable joints — for example, bolts. Other things being equal, they are considered less reliable than solid ones, because. connections are usually the "weak point" of the design; however, for simple flights, this reliability is quite enough, and prefabricated frames are somewhat cheaper. This option is found mainly in entry-level models, as well as in inexpensive middle-class cars.

— Whole. A frame that does not have collapsible joints and is made in the form of an integral structure. Theoretically, this option is able to provide high strength, making it suitable even for professional-level machines. However, in fact, a one-piece frame in itself is not an indicator of a high class model — it is found among helicopters of all price categories, and the quality of the structure, usually, directly depends on the cost.

General dimensions of the model. Note that the length and width are indicated only for the fuselage, excluding the main rotor. However, for ease of transportation, the blades are often made removable or folding.