Drag for RC Helicopters
As with all moving vehicles, they encounter air resistance. This air resistance is called drag. There are three types of drag of an RC helicopter: induced, profile, and parasitic.
Profile drag is drag from the frictional resistance of the blades as they pass through the air. As the blades pass through the air, they run into particles of air and cause resistance.
Parasitic drag is drag from the rest of the helicopter body including the fuselage, the cockpit, the engines, the tail boom, etc. As the helicopter goes faster, parasitic drag increases. Parasitic drag is basically an aerodynamics problem.
How much is a rotor system capable of lifting?
How much a rotor system can lift is determined in part by the aerodynamic lift vector of induced flow. However, thanks to Newton where all actions have equal and opposite reactions, induced flow also carries drag.
What is induced flow?
Induced flow is the airflow that is forced through the rotor blades at a right angle to their direction of travel. Induced flow is relative to the amount of work produced by the rotor system, referred to in aerodynamic language as “angle of attack.” Angle of attack is the amount of lift provided by the rotor system expressed in amount of work done. As lift is being produced, air is flowing over the top of the rotor system and down through the blades. Depending upon whether the aircraft is “in ground effect” or “out of ground effect,” the angle of attack varies. However, the amount of work remains constant. By changing the blade angle of attack, you change how powerfully you “push” the air downward. With a low blade angle, the helicopter may descend, with a medium angle it will hover, and with a high angle it will ascend.
Different Types of Pitch for RC Helicopters
There are two types of pitch controls available in RC helicopters: fixed and collective. Each pitch type has its pros and cons. The pitch refers to the angle of the blades. Blade angle adjusts how the helicopter moves.
Collective pitch helicopters have blades that can have their angle adjusted simultaneously. The amount of life is determined by the angle of the blades. Collective pitch helicopters are harder to build because they have more moving parts. They are more expensive, harder to fly, and cost more to repair. But unlike fixed pitch helicopters, collective pitch helicopters can do fast flights, rolls, loops, and other amazing aerial acrobatics. If the engines die at altitude, the RC helicopter is able to “glide” down safely using auto-rotation (where air passing under the blades as the helicopter falls causes some lift.) Once you have mastered the easier fixed pitch RC helicopters, you can move up to a collective pitch helicopter. With the increased maneuverability comes increased difficulty in flying.
A fixed pitch helicopters mean the rotor blades have a fixed pitch and cannot be adjusted. The amount of lift is dependent only on how fast to rotor blades are moving and not the angle they are pitched at. As you increase the speed of the blades, the helicopter will go up. Lower speeds mean the helicopter has less lift and will come down. Fixed pitch helicopters are easier to build, has fewer moving parts, is less expensive, and is cheaper to repair if you crash it. If the helicopter loses power at altitude, the helicopter will fall like a brick. Fixed pitch helicopters are easier to fly and are suggested for beginner RC helicopter pilots. These helicopters are less maneuverable than a collective pitch RC helicopter.
Parts of an RC Helicopter
It’s important to know the various parts of your RC helicopter. Each component has a role to play in keeping the helicopter airborne.
The rotor system simply refers to the blades the keep the helicopter aloft. The helicopter will have two, four or multiple blades that spin around a central hub above the fuselage. The rotor system provides lift and propulsion for the helicopter.
This is the narrow section of the helicopter the connects the fuselage with the tail. The tail boom is quite light and usually hollow to save weight. The servos and connections that control the tail rotor to the main body of the helicopter, so try not to break this part of the RC helicopter.
This is the small accompanying rotor on the tail of the helicopter that provides a balancing force preventing the helicopter from spinning horizontally. The tail rotor is a vital component. Without the tail rotor, the body of the helicopter would spin right along with the main rotor system.
The body of the helicopter is called the fuselage. This is where all the servos and electronics for your RC helicopter are housed. The battery lives here too. If this were a real helicopter, the pilots and crew would sit in the fuselage. But wait there is more. There are three types of drag: induced drag, profile drag, and parasitic drag. With regard to an RC helicopter, the focus is on the bells and whistles that people like to throw on these things to make them look cool when it actually degrades the performance of all helicopters (RC or real). Parasitic drag effects the aerodynamics of the helicopter. So all of those wham bam sparkly extras actually make your helicopter perform poorly.
RC Helicopters Types
There are several types of RC helicopters. They all have their pluses and minuses. Depending on your skill level, one RC helicopter type may be more appropriate than another. Have a read and see which one would be best for you!
Fixed pitch RC helicopter
A fixed pitch RC helicopter means the rotor blade’s pitch is at a fixed position. Going up and down is achieved by increasing the speed of the rotor system. They have a single main rotor system and a tail rotor to counteract the torque effect. This type is more challenging to fly than a coaxial RC helicopter, but not as difficult as a collective pitch RC helicopter.
Collective pitch RC helicopter
A collective pitch RC helicopter means the pitch of the blades can be adjusted just like a normal helicopter. The rotor speed remains constant and lift is achieved by changing the pitch of the blades. These RC helicopters are the most challenging to fly, but also the truest to life. Collective pitch RC helicopters have the best control of all RC helicopter types. They can auto-rotate and fly inverted. These are the most versatile of the RC helicopters available. They also tend to be more expensive.
Coaxial RC helicopter
Coaxial RC helicopters have two rotors mounted one on top of the other. The rotors rotate in opposite directions thereby canceling out the torque effect. This also means coaxial RC helicopters do not require a tail rotor. These are the easiest to learn how to fly because they are mostly self-stabilizing. These are also the most inexpensive type of RC helicopter.
Whichever type of RC helicopter you choose, hours of fun awaits you! Start small and work your way up. As your skills improve, you can get a more complex helicopter.
What’s the funnest thing about flying an RC helicopter? It seeing your little remote control copter zoom across the sky right over your head. Naturally, that’s what everyone tries to do in the first fly a helicopter. They want to see it zoom back and forth and all over the place.
Of course, this is incredibly hard to do unless you have mastered the art of flying a remote control helicopter. This is why everyone almost fails when they first start flying a helicopter.
They don’t do the basics. They don’t try and even learn hovering orientations.
Learning hovering orientations is probably the most boring part of your RC helicopter training process. This is going to take at least 40 hours for you to get down pat. And it’s something that we highly recommend you do in a consistent basis.
Simply doing this every other Saturday for our here in their won’t help you learn anything. Were talking about you going out in your backyard five days a week and burning through to full battery charges.
Learning hovering orientations is going to do is it’s going to teach you the patient’s that is needed to fly an RC helicopter. In addition, it’s going to teach you how to properly control your RC helicopter.
You’ll be able to learn just how much of an impact even the slightest movement of your joystick is going to have. It’ll teach you how to handle your helicopter when the environment conditions may not be ideal.
Hovering orientations are also going to give you a basis that you can always resort to when you’re trying to learn to fly different RC helicopters and maybe even fly them in a different manner that you’re not used to.
Proper hovering orientations are going to be the basis of your RC helicopter flying career. No matter what you’re always going to be going back to that hovering position when you don’t know what you should be doing.
The hovering position is kind of like the downward dog of meditating. It’s a relaxing position that you don’t even need to think about doing and allows you to calm your nerves and think clearly.
That’s why, for anyone starting out flying RC helicopters, the poor and that they master their hovering orientations.
Utilize the RC Helicopter Community Near You
Odds are, no matter where you live, there is a big RC helicopter community near you. What this means, is that while you may not know anyone who is RC helicopter enthusiast, there is more often than not many people around you that actually are RC helicopter enthusiast.
You can generally find these folks either flying in the designated fields around you were simply by perusing the Internet and looking for local community websites.
Remember, remote control enthusiasts have been around for decades at this point. You’re not going to be the only one that loves to fly an RC helicopter.
The importance of this is that it’s always best to fly with a friend. Preferably, you’re gonna want to find an RC helicopter pilot that is a better mechanic in a better flyer than you.
The reasoning for this, is that there’s always gonna be something that goes wrong when you’re flying. Very rarely are you going to have the perfect flight. Having someone near you that actually has a lot of experience and knows what they’re doing is going to go a long way.
It’s very similar to how when you go out on your boat the first few times, you’re gonna want to bring an experience boater and a mechanic with you. You’re never to have a good time on the boat. Something always goes wrong.
In addition, the experience RC helicopter enthusiasts going to be able to teach you how to fly and give you general pointers during your journey. It’s also a good way to make friends and to learn more about your local community.
Odds are, they also know about community made up sooner to be able to go and experience more time with other helicopter enthusiasts.
The RC helicopter community is one of the best parts about flying RC helicopters. We highly recommend that everyone becomes ingrained in it.