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Basics
The wide spectrum of this whole art can be categorised under different heads such as static modelling & flying.Again in flying -control-line,free flight,radio controlled.These in turn can again be branched out into many.Static modelling involves carving out and constructing scale replicas of actual aircrafts or new designs.This might seem very elementary to you,but you will be surprised once u really get into this art.Static modellers spend months making thier models to best finishing,with most accurate details possible.
Flying of course is always much more fun..!!.You can build/design your model to fly in a lot of ways.Once the basic aerodynamic requirements are complete,u can either control them or set them free.Some models are built to go around in circles,of say about 50 foot radius.These are held by two wires,usually of steel by the flyer who stands in the center.By moving these wires one can make the model take off,land,do a loop..and a amazing no of stunts u cannot even imagine!.Some also practice for speed,scale & combat.These are called control line models.
But for many ,the true thrill comes only when the model really flies up really high,without its flight being restricted by two wires.As the name suggests free flight models are as free as birds.Once launched there is no way to control them.The only control that can be done is by presetting or with timers.These models are built as gliders,without an engine attached to them or one can also use a short engine run to put them high up in the sky.
Next comes,radio controlled,the most realistic,most sophisticated and by far the most thrilling of all!!.These models are controlled by a radio transmitter held by the flyer on the ground and the model can perform every stunt that an actual airplane can.Flying these models is a totally different ball game and it involves a lot of things starting from electronics,control,stability etc.This can again be branched into ,R/C gliders,scale,speed,trainers,aerobatics...etc.R/c models are used for motion picture shots,aerial military surveillance,photography,research ...and of course also for the pure fun of flying.
So you can see that its a whole world of fun!!.Fun fun & pure fun.But grasping the whole art might take some time for you.Even years I might say.And only when you are truly involved in it will you feel the real thrill.Start off with something simple and basic.Knowledge is a very important factor in this hobby.I must warn you that these are not mere toys!!.They have and can cause severe destruction.Try to get as much information as possible before u venture out.
To reduce the chance of frustration, a new modeler should become involved with other modelers in order to learn the necessary skills. This may involve simply visiting a flying site and becoming acquainted with experienced modelers or joining a club. These modelers are a source of knowledge and experience that can be invaluable to the new modeler when he begins to build his first aircraft and when he begins to learn to fly. An experienced modeler can act as an R/C flight instructor to teach a new person the skills required to fly the aircraft properly and to avoid the inevitable crash.
The Basics of Flight
The concepts of flight should be understood by a beginner. The theories behind the physics of flight are covered in many volumes of books. There are different and sometimes conflicting theories and arguments as to how airplanes fly, but the one accepted principle is that lift is generated as a result of the air pressure on the bottom of the wing being higher than the air pressure on the top of the wing.
The Lift Diagram shows some of the basic terms relating to a wing section. These terms are common to R/C flight.
Airfoil - The cross section of the wing
Angle of Attack - The angle between the chord line and the relative direction of flight
Chord Line - The line between the leading edge and the trailing edge of the airfoil
Direction of Flight - The relative direction of the wing in relation to still air
Leading Edge - The most forward edge of the wing
Trailing Edge
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The most rearward edge of the wing
There are four (4) primary forces which act on an aircraft in flight; thrust, lift, drag, and weight. Thrust is the force applied by the combination of engine and propeller acting to pull the aircraft forward. Drag is the resistance against the aircraft by the force of the air against the forward facing surfaces. Weight is caused by gravity. In order for a constant speed to be maintained, thrust and drag must be equal. In order for a constant altitude to be maintained, lift and weight must be equal.
Lift increases as the velocity of the air passing over the wing increases or as the angle of attack increases as long as the flow of air over the wing remains smooth. Actual flight is attained when the force of the lift equals weight.
An aircraft pivots about three (3) axes; the yaw or vertical axis controlled by the rudder, the pitch or lateral axis controlled by the elevator, and the roll or longitudinal axis controlled by the ailerons. It can pivot about any one of these individually or in combination based on the control surfaces that are moved and the direction of the movement.
When the rudder is moved to the right, the aircraft will rotate to the right about the yaw axis and vice versa. When the elevator is moved up, the aircraft will pitch the nose upwards. The ailerons move in opposite directions. When the left aileron is moved up and right one down, the aircraft will rotate to the left and vice versa.
The basic trainer
Aileron - The moveable portion of the wing which causes a change about the roll axis
Cowling - The part of the fuselage which covers the engine
Engine - A 2 - cycle reciprocating machine which provides the motivational power
Elevator - The moveable portion of the horizontal stabilizer which causes a change about the pitch axis
Fin - Properly known as vertical stabilizer which provides stabilization about the yaw axis
Fuselage - The main body of an aircraft
Landing Gear - The supporting structure of an aircraft including landing gear struts and wheels
Propeller (Prop) - The combination of blades which provide thrust
Rudder - The moveable portion of the vertical stabilizer which causes change about the yaw axis
Spinner - Covering over the prop hub
Stabilizer - Properly known as horizontal stabilizer which provides stabilization about the pitch axis
Wing - The horizontal surfaces which provide the lifting forces
There are certain criteria that a trainer should have in order to be satisfactory for a beginner.
High Wing - A high wing model is inherently more stable than a low wing model due to pendulum effect. Since the weight of the model is below the wing, the fuselage tends to swing downward like a pendulum in order to equalize forces.
Flat Bottom Wing - The wing cross section should have a virtually flat bottom. This type of cross section has more gentle flight characteristics that are necessary for a beginner.
Dihedral - The wing should have some dihedral. This means that the tips of the wings are higher than the center. The effect of the dihedral is to try to equalize forces and keep the wings level or to return the wings to a level orientation
High Aspect Ratio - The ratio of the wing length or span should be at least 5 1/2 times the width or chord. This will reduce the rate at which the model responds to command input allowing more time for a beginner to react.
Constant Chord - The width of the wing should be the same from the center or root to the end or tip. This distributes the weight of the airplane evenly over the entire surface of the wing.
Low Wing Loading - The weight of the model divided by the area of the wing should not exceed 250gms./sq. ft. This reduces the speed required to maintain an acceptable rate that the model descends when the power is reduced resulting in a lower landing speed.
Moderate Size - Most trainers are for engine sizes between .15 and .60. The smaller ones are more susceptible to the effects of wind and normally the wing loading is higher simply because of the weight of the radio equipment. The larger sizes are easier to fly and easier to see but are more difficult to transport. Most trainers are for .40 size engines. These trainers have been widely accepted as the optimum size.
Structurally Sound - A trainer must be able to take the abuses imposed by a beginner. This is especially true for hard landings. It must be able to withstand minor crashes with minimal damage. It should be relatively easy to repair.