Comparison i-Helicopter 172 vs WL Toys S929

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 number of control channels provided in the radio-controlled model.

Each such channel is responsible for a separate control function: the operation of the rudder, elevators, etc. For the simplest models, 2 – 3 channels are enough. Full control requires more channels. In advanced models, additional channels may be provided, the total number of which can reach 6 or more.

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.

The type of power source required to operate the helicopter. Note that such sources are required not only for models with electric motors (see "Engine") — any car needs electricity at least to power the radio signal receiver.

— AA. Replaceable cells of a standard size, popularly known as "finger-type batteries". In this standard size, not only rechargeable batteries are produced, but also disposable batteries, which makes it possible to choose: either to buy additional batteries every time as needed for relatively little money, or to pay a large amount for batteries once, but not to spend money in the future. Further expanding the choice is that AA elements have different characteristics and price, but are completely interchangeable. The main advantage over original batteries is the ability to quickly replace dead batteries: they are sold in almost all stores with “household trifles”, and the process itself usually takes less than a couple of minutes. On the other hand, the power of such a power supply is quite modest, and the elements themselves usually require several even to power on-board electronics. In some models, AA elements may be included in the package, but most often the owner of the car has to buy them on his own.

— Ni-Mh. This category includes batteries made using nickel-metal hydride technology and not related to any standard size — that is, having an original shape and characteristics and most often initially “sharpened” for a specific...helicopter model (or series of models). By themselves, the "original" batteries for the most part surpass AA cells in terms of characteristics and allow you to create models with electric motors of quite impressive power. Specifically, nickel-metal hydride batteries are notable for their low cost, reliability, good capacity, no "memory effect" (drop in capacity when charging an under-discharged cell), and resistance to temperature extremes, which makes them very useful for outdoor use. Among the disadvantages are storage requirements: such batteries cannot be stored completely discharged for more than a few days.

— Li-pol. Batteries of the original form, made using lithium-polymer technology. For the original form, see above (Ni-Mh). With regard to this technology, it allows you to create batteries with high capacity, small size and weight and without the "memory effect"; its main disadvantages in the case of radio-controlled models include sensitivity to low temperatures, as well as a rather high cost.

— Proprietary battery. This category includes all batteries of the original standard size (see subparagraph "Ni-Mh" above), for which the manufacturer did not specify the manufacturing technology. They may use one of the technologies described above, or another.

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.

Capable of charging the helicopter battery from a standard USB port. This function is convenient primarily due to the prevalence of the USB standard: it is used in the vast majority of modern computers and laptops as a data transfer interface, and in portable electronics it is also used as a power source for charging batteries. Thus, a model with this feature can be connected for charging to computer equipment — or to any 220-to-USB network adapter. This is more convenient than using a specialized charger (which can also be lost). However the current power during such charging is relatively low, which is why it is poorly suited for powerful batteries.

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 type and number of batteries needed to operate the helicopter control panel.

— AA. Replaceable batteries, colloquially known as "AA batteries". They are available not only in the form of disposable batteries, but also in the form of rechargeable batteries, are produced under various brands that differ in price and quality (which provides freedom of choice), and finding such elements on the market is usually not a problem. The power and capacity of AA elements are relatively small, but in most cases they are quite enough for normal operation of the transmitter for quite a long time. Usually, modern remotes require several of these batteries — usually 2, 4 or 6.

— AAA. Also known as "pinky". In fact, a smaller version of popular AA elements (see above); has the same key features, but differs in more compact dimensions and, as a result, somewhat reduced power. This option is typical for low-cost class models, with a small range of the remote control.