Understanding Swashplate Control Systems - JR Venture CP Assembly Instructions Manual

Assembly instructions manual (42 pages)

Table of Contents

Currently, there are several different types of control systems available on the market. Although the mechanical methods for

transferring control to the swashplate vary, the different control systems can be broken down into two categories:

One-Servo (Conventional)

CCPM (Cyclic/Collective Pitch Mixing)

The following is an explanation of the two most popular types of swashplate control.

One-Servo Standard Swashplate Control (Conventional Helicopter)

The One-Servo standard system is found in a wide variety of radio

controlled helicopters. The term "One-Servo" means that the control

system requires one servo to operate each separate swashplate

function. With this system, a total of three servos is required to operate

the three main swashplate functions, which are aileron (roll), elevator

(pitch), and collective functions. With this type of control system, each

servo works independently and is assigned to a specific function. In

other words, the aileron (roll) servo is assigned to move only the aileron

(roll) function, as is the elevator (pitch) servo, etc. Since these servos

operate completely independently of each other, the servo torque to

each control surface is limited to the maximum torque rating of the

servos used.

The One-Servo standard system swashplate is designed so that the

lower swashplate ring control balls are spaced at 90° to each other. This

system is also most commonly arranged so that the aileron (roll) axis of

the swashplate is positioned at 90° to the main mechanics of the

helicopter, and the elevator (pitch) axis is parallel to the mechanics.

Please refer to the diagram at right for clarification.

With this type of system, it is necessary for the helicopter to be designed using an intermediate mechanical mixing system so that

the control inputs can be transferred from the three independent servos to the swashplate in such a manner that the three controls can

be achieved. This mechanical mixing system allows the swashplate to both roll (aileron) and pitch (elevator), as well as slide up and

down the main rotor shaft for collective pitch inputs. These mechanical mixing systems generally require the use of many ball bearings

and control rods to achieve this result.