RC Model Helicopter Guide

What are RC Model Helicopters

Radio-controlled helicopter (also RC helicopter) is model aircraft which is distinct from a RC airplane because of the differences in construction, aerodynamics, and flight training. Several basic designs of RC helicopters exist, of which some (such as those with collective pitch control) are more maneuverable than others. The more maneuverable designs are often harder to fly, but benefit from greater aerobaticcapabilities.

Flight controls allow pilots to control the collective (or throttle, on fixed pitch helicopters), the cyclic controls (pitch and roll), and the tail rotor (yaw).Controlling these in unison enables the helicopter to perform the same maneuvers as full-sized helicopters, such as hovering and backwards flight, and many that full-sized helicopters cannot, such as inverted flight (where collective pitch control provides negative blade pitch to hold heli up inverted, and pitch/yaw controls must be reversed by pilot).

The various helicopter controls are effected by means of small servo motors, commonly known as servos. A solid-state gyroscope sensor is typically used on the tail rotor (yaw) control to counter wind- and torque-reaction-induced tail movement. Most newer helicopters have gyro-stabilization on the other 2 axes of rotation (pitch and roll) as well. Such 3-axis gyro is typically called a flybarless controller, so-called because it eliminates the need for a mechanical flybar.

The engines typically used to be methanol-powered two-stroke motors, but electric brushless motors combined with a high-performance lithium polymer battery (LiPo) are now more common and provide improved efficiency, performance, and lifespan compared to brushed motors, while decreasing prices bring them within reach of hobbyists. Gasoline and jet turbine engines are also used.

Types of R/C helicopters

Common power sources of remote control helicopters are glow fuel (also called nitro fuel, nitromethane-methanol), electric batteries, gasoline (petrol) and turbine engines. For the first 40 years, glow fuel helicopters were the most common type produced. However, in the last 10 years, electric powered helicopters have matured to a point where power and flight times are better, but typically not as long as glow fuel helicopters.

There have been two main types of systems to control the main rotors, mechanical mixing and cyclic/collective pitch mixing (CCPM). Most earlier helicopters used mechanical mixing. Today, nearly all R/C helicopter use CCPM.

Practical electric helicopters are a recent development but have rapidly developed and become more common, overtaking glow fuel helicopters in common use. Turbine helicopters are also increasing in popularity, although the high cost puts them out of reach of most people.

Internal Combustion (Nitro, Gas)

The first RC helicopters have been powered by combustion engines (Glow fuel, or nitro, as well as gas, or gasoline as the fuel source). Original helicopter "classes" were based on the engine size. For example, a helicopter with a 0.30 cu in (4.9 cm3) engine was a 30 class and a helicopter with a 0.90 cu in (14.7 cm3) engine was referred to as a 90 class helicopter. The bigger and more powerful the engine, the larger the main rotor blade that it can turn and hence the bigger the aircraft overall. Typical flight time for nitro helicopters is 7–15 minutes depending on the engine size and tuning.

Electric

The 252 km/h fast electric helicopter TDR

Two small electric helicopters emerged in the mid-1990s. These were the Kalt Whisper and the Kyosho EP Concept, flying on 7–8 × 1.2 Ah NiCad batteries with brushed motors. However, the 540-sized brushed-motors were on the limit of current draw, often 20–25 amps on the more powerful motors, hence brush and commutator problems were common.

Recent advancements in battery technology are making electric flying more feasible in terms of flying time. Lithium polymer (LiPo) batteries are able to provide the high current required for high performance aerobatics while still remaining very light. Typical flight times are 4–12 minutes depending on the flying style and battery capacity.

In the past electric helicopters were used mainly indoors due to the small size and lack of fumes. Larger electric helicopters suitable for outdoor flight and advanced aerobatics have become a reality over the last few years and have become very popular. Their quietness has made them very popular for flying sites close to residential areas and in places such as Germany where there are strict noise restrictions. Nitro helicopters have also been converted to electric power by commercial and homemade kits.

The smallest remote-controlled production model helicopter made (Guinness World Records 2006) is the Picooz Extreme MX-1 sold at many toy stores (although this is infrared controlled, not radio), electronics stores and internet stores, costing about $30 (£28). The next smallest is the standard Picooz helicopter.

Multirotor model helicopters

More recently, multirotor designs have become popular in both the RC hobby and unmanned aerial vehicle (UAV) research. These vehicles use an electronic control system and electronic sensors to stabilize the aircraft. Multirotors are generally more affordable, easier to construct, and simpler to operate than RC helicopters. This made multirotor aircraft an appealing platform for amateur model aircraft projects and aerial photography.

Size classes

Nitro RC helicopters are categorised under the following classes:

  • 30 size : Engine 0.3 cubic inch, Main Blades 550-600mm
  • 50 size : Engine 0.5 cubic inch, Main Blades 600-620mm
  • 60 size : Engine 0.6 cubic inch
  • 90 size : Engine 0.9 cubic inch, Main Blades 690-710mm

Modern RC helicopters are generally classed by the length of the main blades (with few exceptions). Common classes are:

  • Micro (under 200mm main blades)
  • Mini (240-420mm blades) - classically called 300-450.
  • 500 (425-500mm)
  • 600 (600mm)
  • 700 (standard competition size)
  • 800

How long do the batteries last?

Our staff can provide a estimation based on model specification battery capacity but as this is ultimately both model (specification) and Flyer (style).

Do you sell spare batteries?

For all Electric and Nitro Helicopters we have a range of Batteries at Hand. most Helicopters use a LiPoly Battery . Be sure to check the cell’s specification in terms of dimensions, capacity, output and crucially the connector to ensure compatibility. Do get in touch if you would like purchase advice regarding batteries and chargers as it can be complex.

How long does it take to charge?

This will vary and is dependent on both the battery and charger specifications so please refer to the manufacturer's documentation. Charging time can be worked out by dividing the batteries capacity by the charge rate. We stock several high-powered chargers that not only charge cells in a fraction of that time but can also handle the charging/discharging/balancing processes associated with advanced LiPo batteries.

What should I start with ?

A good begineer model, starts with something simple, that has readily avaliable parts and comes as an RTF ( Ready to Fly ) Package. There are some excellent more advanced models that could also double up as begineer models, but with some kits, you will require 

1. Battery
2. Battery Terminals
3. Charger
4. Remote Control
5. Reciever

with this parts in place, you should then be able to own and fly several models, as you grow in the Hobby, without having to change your base equipment ( Please note that the Batteries for one Flying RC Model Helicopter , may not suite another, due to weight size and number of cells)