Chapter 6 : Choosing My First Model Helicopter

So far we have discussed some theories on the previous chapters which I hope I have imparted to you clearly. This chapter is now is for preparation on starting to choose the type of model helicopter suited for the beginner. The most appropriate model to choose is the non-colletive type. Meaning, the main rotor blade's pitch is fixed. It will only depend on the speed of the rotor blade and engine to gain or lose lift unlike the variable pitch type that can adjust the pitch to improve the lift performance. But in my experience, I started with the collective type and learned to fly and hover it with not much difficulty. Only the complexity in set-up hinders the learning progress because you have to align the main blade pitch and the angle of attack or main blade pitch using the blade pitch meter. The tail rotor also have to be trimmed against the main rotor torque by mixing the tail rotor's pitch which is syncronized to the main rotor blades pitch and speed which very important before flying the heli.

Not only the collective pitch of the main rotor baldes that we should consider. The design of the main rotor head is essential on choosing our first model. Most of the design on the market has a flybar attached perpendicular to the main rotor head. This design has a built-in stability compared to a flybarless design. There are other types also like the bell-hiller system, multi-bladed system, hiller system which are quite complicated and not suitable to a beginner. A typical rotor head design with flybar is shown here in Fig.3 from chapter 1.

Now we go to the fuselage. For the beginner, it is recommended to have an open stark fuselage for simplicity of operation. For example, in an open type, the engine is easily accessible for starting and for maintenance. It will also help the cooling system of the engine unlike in an enclosed type. And with regards to the size, a .30 cu. in. engine is also suitable because a bigger .60 cu. in. consume a lot more fuel and damage to people or properly is more than it's smaller counter part. To see a typical model helicopter with a stark fuselage, see Fig. 1 from Chapter 1.

For far we have discussed selection and been familiarized with the model to choose. But there are some finer points to discuss with regards to pre-flight preparation.

Area selection - the most suitable is a closely mowed grass area, a putting green ,or a golf course if you can find one! Just kidding, just an average lawn grass is OK. The advantage is when the helicopter tip over, it will not be too hard on the blades.

If there are no available lawn, an aspalt or concrete is alright but the gritty dust of the deteriorating asphalt will cause wear and tear to your engine and mechanical parts. The best thing to do is to sweep it first with a broom and or wash it down with a water hose,

Training gear - this serves as a protection to the main rotor blades from hitting the ground while learning to hover. The construction is two pieces of 1/2" dowel rods 3 feet to 4 feet long laid in an "X" pattern. The ends were attached with 4 pcs. 4" whiffle balls. ( See Fig. 28 )

Figure 28: Model Helicopter With Training Gear Attached

Trimming the landing gear - this part is very helpful to speed up the learning process. As we have discussed before about the translating tendency, ( see Fig. 17 from Chapter 3 ) the tail rotor blows the helicopter to one side which tends to drift it. The cyclic control is not effective while the landing gear is still touching the ground. To counteract this, we need to tilt the helicopter by attaching a 3/8" square wooden stick on one side of the skid. So the model will lift off the ground without applying a control input on the cyclic control which is difficult and might be overcontrolled.

Figure 29: Wooden stick Attached to Skid to Tilt the Heli

So this wraps up the RC helicopter for Dodos and I hope you have absorbed the important topics before starting this hobby. I recommend buying the RC helicopter manual to further enhance your knowledge. So thanks and have a good day!