Comparison Na-Na IM180 vs Thunder Tiger Mini Titan E325 V2 SE Kit

The configuration of a radio-controlled helicopter usually determines not only the equipment supplied with the model, but also how ready the device is to fly out of the box.

— RTR (RTF). Abbreviation for "ready to run" (or "ready to fly"), that is, "ready to use." As the name suggests, these helicopters are delivered fully equipped and assembled, and the most that will have to be done after unpacking is to charge the batteries and/or install batteries. This option is optimal for those who want to get a workable device without wasting energy on assembly and debugging.

— Kit (set). Such kits are supplied as a set of individual parts, from which the user must independently assemble the finished machine. Also in such cases, the kit may not include an engine, a battery (for electric models, see "Engine"), a silencer (for internal combustion engines), servos and other necessary equipment — it is assumed that the owner himself will choose the necessary components at his discretion. "Whales" are designed for fans of modeling, for whom the assembly process is of particular interest; we note that the assembly itself most often requires certain experience and skills.

— ARR (ARF). "Almost ready to run" (or "... to fly") — "almost ready to use." This option is a cross between the above-described kit (kit) and RTR (RTF): the helicopter is delivered disassembled, however, the assembly of...the machine is quite simple and usually comes down to installing individual parts on the “seats” intended for them. Yes, and additional parts have to buy less (if at all). ARR is well suited, for example, for beginner modellers, or for amateurs who do not want to spend a lot of time and effort on assembly.

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.

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 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.

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).

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.