RC Helicopter Lingo
Just to get you started let’s review the lingo. As you read this buying guide you will see these abbreviations as well as on other websites. You need to learn and know what function it serves.
FP: fixed pitch
Simple propellor set at installation, cannot be adjusted during flight.
CP: collective pitch
the angle of the rotor blade can be changed to assist with the lift.
CCPM: Cyclic, Collective, Pitch Mixing
cyclic, collective pitch mixing–a digital control system using three servos aligned nearby the swashplate to unite elevator, aileron, and collective-pitch functions.
ARF: Almost Ready to Fly
Almost ready to fly, usually needs radio gear installed or minimal assembly.
RTF: Ready to Fly
Ready to fly, includes everything. Just unwrap, load the batteries, and go fly.
BNF: bind and fly
A marketing term from Horizon Hobby describing Park Zone and E- flite models which come preassembled and ready to fly; all you need to do is bind them to a compatible 2.4 GHz radio.
The flybar provides some endurance to the rotor head. An FBL system is a multiple-axis gyro that substitutes the flyer on the main rotor head. Rather than mixing lever location and tinkering with paddle weight, you can alter a ton of parameters using a software interface. Many also substitute the tail gyro.
How To Start
In recent past years, RC helicopters were nothing more than a curiosity. There were a handful of kits available on the market, and you had to be a mechanical engineer to assemble them together.
There might be one or if you’re lucky, two — helicopter pilots in a local flying area. Helicopter pilots would generally be left to themselves, subject to a range of whispered jokes such as, “Those things do not fly; they’re so ugly the earth repels them,” or “They do not fly, they hit the air into submission,” and others. Recognizing looks were exchanged by the plane pilots who said, “He is a nice enough guy, but he is a bit odd; he flies helicopters.”
Fast forward to now. At the many fields, the helicopters present at an area can equal or even go beyond the number of airplanes. Also if they’re hidden in the back seat of the trucks, lots of the sneering plane pilots secretly have one or two electric helicopters.
Today there are so many kits available in almost every possible shape and size that a learner concerned in getting started in the hobby can easily be overwhelmed. Offerings vary from RTF helicopters that you can charge & can unpack, charge and fly to kits, that you have build from bags of components.
What Do You Need?
Sizes range from tiny electric-powered prototypes that you can fly on inside your home to turbine-powered scale gems that need a trailer to move them to the flying area. A first- time helicopter purchaser is very likely to experience a confusing array of conditions like ARF, BNF, RTF, fixed pitch, coaxial, collective pitch, electric, nitro, and gasoline.
In this post, we explained those terms, in the beginning, to get you started and help the helicopter client make an informed decision regarding which category best suits her or his needs and interests.
Standard helicopters used to be categorized the displacement of their nitro- and methanol-fueled motors. The .30 and .60 size motors were the most common in the past using the .30 size setting 500mm to 550mm blades and operating engines from .28 to .32 cu. in
In the endless quest for “more power,” the.30 size evolved to the .37 into .39 ranges, then .46 and today’s .50 into .56 cu. in engines. Blades got abundant, and booms had to be extended to absorb the enhanced power. A contemporary .50-class helicopter generally changes 600mm to 620mm principal rotor blades.
The next class up was complex and the expensive .60-size models which have evolved into the fire-breathing .90-size monsters turning blades that are 700mm blades.
Modern electric-powered helicopters are more expensive and hard to classify size wise, but they generally include rotor spans in the 7-inch range (the tiny T-Rex 100) into the 700 sizes, spanning nearly 51/2 feet.
Loose comparisons could be made to nitro-powered helicopters. A 550 electrical is the same size as a .30-size fuel- powered helicopter; a 600 electrical is .50 size, and a 700 electrical is .90 size. The 100 through 450-size electrics smaller have no mainstream fuel-powered equivalent.
credit: Modellflugtreffen in Damelang Germany, RC MEDIA WORLD
Many factors go into determining which size helicopter to purchase. The first factor ought to be price. Create a realistic assessment of how much you can afford to spend on your purchase.
Budget for everything you need including radio, the kit, servos, gyro, or flybarless unit, and support equipment. Do not forget to allow for replacement components. If you spend your total budget on the kit and radio but cannot afford to substitute usually crash-damaged parts such blades, the primary shaft, servo gears, etc., you will feel frustrated.
Think what would be the result if you crash on your first weekend and your helicopter must sit in a heap for quite a while until you can replace the broken component. Several individuals fall into this snare, came out a few times and never return.
Great strides are being made in stabilization systems, gyros, and quality of the smaller, affordable helicopters on the market now, but, bigger flies better. Bigger helicopters are both more durable and more pleasant to see.
The drawback, of course, is that the more significant is more expensive they are to purchase and operate. You will find RTF electrics which come complete with a transmitter which doesn’t cost a lot more than a pair of carbon blades for a .90-size machine.
Where you want to fly is another factor to consider in buying choice. Any nitro-powered helicopter, as well as 500 sizes and bigger electric-powered helicopters, requires a good bit of space in which to be reliably flown. These items can be dangerous; security should be your first concern when deciding when and where to fly.
Different from an airplane, a helicopter needs four main flight controls: roll (aileron), yaw (rudder or tail rotor), pitch (elevator), and throttle. The ailerons and elevator are combined on the perfect stick (Mode 2) in what’s known as the cyclic control. This is what provides us directional control of the helicopter.
Rudder control is accomplished either by a variable-pitch or variable-speed tail rotor that is controlled by the rudder stick. The rudder control turns the helicopter nearby its main rotor shaft. There are two rare instances where yaw is regulated separately (coaxial and tandem rotor helicopters).
An additional station is required by collective-pitch helis to control the pitch of the rotor blades, so the pitch is raised or lowered at precisely the same time. This is mixed with strangling to keep a constant head speed and activated by the throttle stick.
Rotor Head Designs
As stated, we generally have two kinds of rotor head layout: a pitch that is a collective and fixed pitch. Fixed pitch’s benefit is that the design is simple, so it’s inexpensive to produce.
As the name suggests, the pitch angle of the principal rotor blades is set and the number of lift changes by altering the rpm of the rotor head. Besides the design’s simplicity, a fixed-pitch rotor head needs only one channel to manage height.
The drawbacks of fixed pitch are that performance is somewhat limited, and if you have the rotor head slow when descending, you may not get the rpm back in time to avoid collision with Mother Earth.
While basic aerobatics can be achieved with remarkable models by using speed, the continued inverted flight is exhausting; once altered, the helicopter could be forced straight down.
Collective-pitch helicopters alter the amount of lift in the rotor system by changing the pitch of the principal rotor blades. The benefits are precise control of elevation, and since the blades can be programmed for negative pitch, continued inverted, and the 3-D flight is feasible.
When you see the astounding flying of some of the pilots such as Bobby Watts, Bert Kammerer, along with many others, they are operating a collective-pitch helicopter with an enormously high power-to-weight ratio.
credit: Bobby Watts
The drawback is that the rotor head has more components, so it is more difficult and more expensive to fix. Collective pitch requires a radio with helicopter programming and another channel to slave the throttle and pitch channels.
The bottom line is that if you want economical and straightforward, a fixed-pitch helicopter is a thing to do. They’re small, relatively simple to fly (particularly the coaxial type), and may be operated using a smooth four-channel radio. If you prefer aerobatics, you may need a collective pitch, and your purchase price will go up.
The torque generated by the main rotor must be counteracted, or the fuselage of the helicopter will twist in the reverse direction of the rotor. This is accomplished by the inclusion of a tail rotor.
Like the central rotor system, the tail rotor could be either a fixed-speed variable-pitch device or a fixed-pitch variable-speed device. Fixed-pitch tail rotor devices have a motor fixed on the variable pitch and the tail ones to drive the rotor from the main engine.
Many 3-D-style helicopters have a variable-pitch tail rotor; however, there is a couple of helicopters with a fixed-pitch tail rotor work pretty well. The E-flite Blade 400 is one heli.
Coaxial helicopters can do away with the tail rotor as the counter-rotating main rotors stop the torque from each other.
Yaw control is accomplished by altering the power to one of the rotors.
Generally, coaxial helicopters are fixed pitch, genuinely inexpensive, and easy to fly. A number of the coaxial helicopters now that are available even include attractive snakelike bodies.
Tandem rotor helicopters like the Chinook also apply counter-rotating main rotors that offset each other’s torque. Until lately tandem rotor helicopters were assigned to the high-end scale assortment, but there are a small few small electric-powered helicopters on the market with Chinook-like bodies and tandem rotor heads.
Fuel or electrical power
The debate between electric power and fuel power was going like the Energizer Bunny. The winner is… there is no obvious winner. Each has its own learning curves and special support equipment to buy.
In the case of fuel power, you require glow plugs, fuel pump, and a means to light them, and, of course, gas. Then, you need to learn how to tune and operate an internal-combustion engine. Most fuel-based helicopters utilize conventional model fuel ( oil, methanol, and nitro-methane). However, there are two-stroke gasoline-powered motors available also.
Multiple flights can be made on a single receiver battery so you can find many flights in a while only holding to refuel.
If you select electric power, there are speed controllers, batteries, and motors to buy. To explain how to choose your electrical system components like batteries, electric motor, and the speed control would encircle a small book.
Luckily, there are several packages provided with elements chosen from extensive flight testing, which are demonstrated to work well together. Then you have to find out how to appropriately charge and handle LiPo batteries.
If you feel that flying site size or noise is the primary consideration, then electrical may be the best option for you.
Moreover, the raw power of some of the bigger (600 and Up) size electrical machines is something to behold.
The drawback is that you need collections of batteries to remain in the air and evade looking at a charger waiting to fly the heli. If you wish to make the most of your flight experience and have constant power the entire flight, and you’ve got access to a large field with no cranky neighbors fuel might be the better option.
How To Proceed
Do your homework before you buy! Visit your local flying area and see what the pilots there are currently flying. That’s a terrific opportunity to hang out with fellow pilots, and you can have an expert pilot to operate your heli before you fly it. It is a trust builder to comprehend your helicopter run and trimmed out by an expert modeler.
Visit the RC forums online including RC Universe or Ray’s Authoritative Helicopter Manual or DVD series.
HeliFreak.com is another terrific resource. The Bob “Finless” White collection of instructional videos that covers a wide range of topics and products and has helped many new builders and pilots is available online at no cost.
Consider buying an RC simulator, for example, Great Planes Real Flight. The investment on a simulator will pay for itself several times over.