FeiYu Tech FY-20A User Manual

GuiLin FeiYu Electronic Technology Co., Ltd http://www.feiyudz.cn E-mail: [e-mail]

Switch channel signal input

900-1200μs

1200-1800μs

1800-2100μs

Functional Mode

Auto balance mode

3D mode

Stabilization OFF

900-1200μs Auto balance mode

1200-1800μs 3D mode

1800-2100μs Stabilization Off

FeiyuTech

FY-20AFlight Stabilization System

installation & operation manual

Dear Pilot,

Thank you for purchasing the FY-20A stabilizer from FeiYu Tech.In order to achieve full potential

and safe operation of this product, please carefully read this manual prior to installation.

Warning:

 The installation and use of this device require some skill and knowledge in flying remote

controlled fixed wing aircraft.

 If you are a new to the hobby and have never flown one before, we do not recommend you

install this device on your own.

 Please find assistance from an experienced flier who may provide you with the basic

knowledge required to use this device successfully.

 If you are already an experienced flier, you will find the installation to be easy and logical.

Just follow the instructions as stated in this manual and you won’t go wrong.

You may e-mail us directly for assistance; [e-mail]

OVERVIEW

The FY-20A is a flight stabilizer for fixed wing aircraft based on inertial motion sensing. It utilizes
a 3-axis gyroscope and 3-axis accelerometer to control the aircraft attitude in all 3 dimensions. The unit
can be activated or de-activated via a spare channel from your receiver. Functions include:
 Level flight – when you need it,the FY-20A will automatically level the flight attitude of your

aircraft. If you are just learning to fly, this will help you gain experience, log more flying time and
increase your confidence. The FY-20A can be left activated throughout the flight duration, from
take off until you landing.

 Emergency Recovery – in case you lose orientation or you feel the aircraft is out of control,

activate the FY-20A via the switch and release of the control sticks. The FY-20A will automatically
bring the plane back to level flight.

 Precision Flying: For experienced pilot, FY-20A can help you achieve more leveled and precise

flight paths, especially when flying and landing in strong wind.

 First Person View (FPV): For long distance flying or FPV, the FY-20A will take on the job of

leveling the plane for you. Just point the plane where you want to go and enjoy the view!

System Working Principle

The Flight Stabilization System (FSS) in the FY-20A is an integrated 3-axis gyroscope and 3-axis
accelerometer. This forms a comprehensive inertial based navigation platform that calculates 3D flight
attitude using proprietary FeiYu Tech algorithm.

When activated in Balanced-Mode, the FSS detects any changes to the model’s horizontal attitude.
If attitude change is detected, the unit will send out controlling signals to the plane’s ailerons, elevator
and rudder to counter that change.

By continuously doing this, the plane is kept in a state of equilibrium, resulting in a smooth level
flight. The aircraft pitch attitude (nose up or down) is automatically controlled via the elevator, while
aircraft roll is controlled through the ailerons. Flight direction to the left or right is automatically
corrected via the rudder servo.

To achieve level flight, the pilot need only release the flight control sticks (aileron, elevator,
rudder) so that they return to the transmitter neutral (middle) position. The model will immediately
revert to level flight.

When used in the 3D-Mode, if an aircraft is in an acrobatic flight, the activated FSS will
automatically counter the rolling speed detected by the 3-axis gyros using all 3-axis controls (rudder,
aileron and elevator). The plane will therefore maintain its last attitude state.

The FY-20A can be used in any environment both indoors and outdoors, and in any weather
condition. After installation, it does not need any other initialization. Just switch on the power and your
plane can take off in stable flight.

FY-20A Package:

In each box of FY-20A, you will receive the following:

 1 x FY-20A circuit board.
 4 x Receiver connecting wires
 2 x double-sided tape or Velcro fastener
 1 x shock absorbing platform with 4 rubber bands

already installed

 1 x instruction manual for FY-20A

Technical Specification and working requirements:

Input voltage : 4.0 to 6.0 Volts
Current draw : 52mA (5V)
Size : 55 x 33 x 20 mm(2.17 x 1.3 x .79 in)
Weight (excluding wires) : 20g(.71oz)
Temperature range :-25°C~ +70°C(-13°F~+150°F)
Maximum rate of rotation : ≤ 1200 ° / s

Application

The FY-20A can be installed in the following aircrafts:

1. Normal / Traditional fixed-wing planes

2. Delta-winged plane with rudder

3. Delta-winged plane without rudder,

4. Plane without aileron,

5. V –tail plane with aileron

6. V –tail plane without aileron

7. Any other configuration, please e-mail us for enquiry: [e-mail]

Remote Control system requirement:

The FY-20A has been tested to work with the following RC systems:

 Robbe-Futaba PPM / PCM 1024 / PCM G3 mode, 2.4 GHz systems；
 Graupner/JR PPM 8, PPM 12, SPCM mode；
 MPX PPM8, PPM 12 with UNI mode;
 Any remote control system using the standard of 1.5 ms neutral position.

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FY-20A Flight Modes

a) The FY-20A can be activated to fly in 3 flight modes. You may choose these flight modes via one

free receiver channel and a 3-position switch from your computer radio:
 Mode 1 : FY-20A Deactivated. In this mode, all control of the aircraft is by the pilot. FY-20A

does not participate in flight control.

 Mode 2: 3D-Mode. In this mode, FY-20A will automatically recognize the latest position of

the aircraft, and give controlling signal to keep the aircraft at the last attitude upon activation
of 3D-Mode. All 3-axis will be stabilized, making your 3D acrobatic movement smoother.
However, please note that this last attitude will be kept for less than 10 seconds. Continuous
pilot input is still compulsory for safe aerobatic flying.

 Mode 3: Auto balance mode. When in this mode and with your transmitter control sticks at

center, the FY-20A will continuously send out controlling signal (aileron, elevator, rudder) to
ensure the aircraft maintains its horizontal level flight attitude and stable direction. In this
mode FY-20A will not allow acrobatic flights.

b) To select the modes, set your End Points Adjustment (EPA) for the 3-Position Switch as follows:

c) You may also use a 2-position switch, at maximum and minimum End Points (EPA) to activate or

deactivate flight stabilization (therefore omitting 3D-Mode).

d) If the FY-20A does not detect any incoming signal to the Switch Channel Input, it will

automatically engage Mode 3- Auto Balance Mode. However, we DO NOT recommend flying
the unit with no signal input to the Switch Channel. It is possible that the auto balance will not
function properly if the Switch channel is left open.

e) We DO NOT recommend landing in Mode 2: 3D-Mode. In 3D-Mode the aircraft attitude is not

tuned for smooth landing.

f) Please note that the FY-20A operation does not involve the Throttle channel. The FY-20A has no

control over your aircraft Throttle. Your throttle channel should be connected directly from your
ESC to your Receiver (channel 3 for example), and operated in a safe manner.

g) Warning: The Auto Balance Mode will provide a smoother leveled landing for your aircraft.

However, note that the turning radius is much larger when FSS is activated. Please ensure your
landing area has adequate clearance for this larger radius.

Schematic diagram of stabilization control (Auto Balance Mode):

IMPORTANT: RADIO PROGRAMMING

1. Remove all existing mixing function already programmed in your radio.

2. The FY20A will do all the differential mixing, not your radio.

3. Program your radio like a traditional plane layout(rudder, aileron and elevator).

FY-20A Connection Interface

The list of the pin Interface:

Gyroscope initialization (re-setting):

Out of the box, the FY-20A has been fully initialized. However, if the following conditions occur,

GuiLin FeiYu Electronic Technology Co., Ltd http://www.feiyudz.cn E-mail: [e-mail]

Servo 1

Servo 2

Servo 3

Aileron

servo

Elevator

servo

Rudder

servo

Servo 1

Servo 2

Servo 3

Rudder

servo

Elevator

servo

Don't

connect

Servo 1

Servo 2

Servo 3

Differential

servo 1

Differential

servo 2

Rudder

servo

Servo (blue arrow) is plugged wrongly
resulting in the signal wire (white) missing
the FY20A signal pin.
This results in the incoming power cable
(RED) and servo wire (BLACK) short
circuiting (red arrows).
This will short circuit your battery or BEC!

DOUBLE CHECK YOUR
INSTALLATION BEFORE FIRST
TIME POWERING UP!

A

B

v. We do not recommend using

your transmitter trims to level
your aircraft in Auto Balance
mode, as the new trim settings
will affect your aircraft when you
revert to Manual Mode. It is best
to land and adjust the FY-20A
installation.

resetting and initialization is recommended:

1. The device has not been used for a long time.

2. There is a change in environmental temperature of over 30 degrees.

3. When in Auto Balance Mode, and the installed device in the horizontal position, the plane

control surfaces begin to move and deflect by itself, without input from the pilot.

Initialization / Reset Procedure

Install the jumper as shown in this picture:
Power-ON the FY-20A and keep it stationary for at least 20
seconds. You will notice the red light blink with two different rates.
After 20 seconds the re-setting / initialization is complete.
Disconnect the power, unplug the jumper and remove (keep it in a
safe place for future use).

NOTE:

 Carry out this re-setting procedure only if the three conditions (above) occur. We do not

recommend regular scheduled re-setting. It is NOT necessary and NOT recommended.

 The stabilizer unit does not need to be in a horizontal position during initialization. However,

you must ensure there is no vibration during this process. If you suspect shaking had occurred,
just restart the initialization / resetting process.

Electrical Connection and Diagram

a) FY-20A Power

 The FY-20A operates between 4 to 6 volts input.
 FY-20A is powered via the Receiver connection.
 If your plane is electric powered, the Receiver power supply is normally from the ESC.

Alternately, you can supply the Receiver and FY-20A via a separate battery elimination circuit
(BEC).

b) Connection between the FY-20A and RC Receiver output is via the supplied wire:

Do not remove this jumper. Leave it installed as long as you are using the mixing function.

Rudder-Elevator Mixing

The Jumper should NOT BE USED if you want to do Rudder-Elevator Mixing, because FY-20A does
not support Differential-Mode stabilization for rudder-elevator mixing.
Therefore, the rudder-elevator differential control for V-tailed planes must have an add-on mixing
device for the corresponding differential channel before connection to the servos:

VIBRATION CONTROL

a) The FSS in the FY-20A is vibration-sensitive. To optimize its stabilization capability, vibrations

reaching the unit must be kept at a minimum.

b) Therefore when installing this flight stabilizer, we highly recommend that you install it with the

supplied shock absorbing platform.

c) The algorithm in the FY-20A compensates for normal levels of flight vibration. However, if the

vibration experienced by the unit exceeds the acceptable level, it will NOT work normally or may
even stop working altogether.

d) To keep vibration at a minimum, install the FY-20A away from the engine or any other vibration

sources.

e) The included shock-absorbing mount will meet the damping requirements of electric powered

aircrafts and most gas / nitro planes.

f) If you receive your shock absorbing mount uninstalled (A), assemble it as shown below (B):

FY-20A requires a minimum of 5-channel RC receiver.
c) 3 Receiver channels are used for aileron, elevator and rudder signal output. Connect these 3

receiver output signals to the FY-20A with the supplied wires.

d) 1 Receiver channel is required to control the FY-20A working mode via a 3-position switch.
e) Example Minimum 5 channel receiver:

Channel 1 = Aileron Signal Output
Channel 2 = Elevator Signal Output
Channel 3 = Throttle Signal Output
Channel 4 = Rudder Signal Output,
Channel 5 = Switch channel with 3-position switch to control FY-20A working modes.

Connection Warning

Be very careful when you are plugging in your servos / connectors. Wrong installation can result in
damage to your power supply or your Receiver.

Double check your installation and ensure ALL connectors are plugged in correctly. Example of wrong

installation:

g) Use the supplied Velcro strips to mount the FY-20A to the

suspended platform.

h) Mount the entire unit to the plane using double sided tape

(recommended), Velcro, screws or glue.
Only the vibration damping pad is enough when the vibration is not

so big.

The supplied Damper Mount will take care of most aircraft

vibrations, unless it is (the vibration) too severe.

WARNING: VIBRATION CHECK

Even with the shock absorbing mount, your aircraft installation may not meet the damping
requirements of the FSS. To confirm correct vibration damping, please follow this procedure:
A. After connecting all wires between the Receiver, FY-20A and Servos, install the unit as

recommended (ensure correct orientation).

B. Run the plane engine or motor at different throttle levels. DO NOT TAKE OFF.
C. Move the throttle level to different positions and maintain it for 20 seconds at each position.
D. At each throttle position, observe the state of the red and blue lights flashing from the FY-20A.
E. If the red and blue lights both stay ON solid, then the vibration dampening is not enough. You

will need to add additional dampening support or change the installation location.

F. If the red light maintains a steady flashing, and the blue light is OFF, this indicates the vibration

dampening requirements have been met.

FY-20A INSTALLATION: ORIENTATION, POSITION & LEVEL

i. The FY-20A has an arrow printed on the top of it. Orient the arrow towards the front of the craft

(i.e. direction of flight).

ii. When installing, please keep the FY-20A horizontal and as close as possible to the "Centre of

gravity" (CG) of the aircraft.

iii. The control benchmark of the FY-20A is its horizontal position. Therefore, ensure the FY-20A is

in the horizontal position when the plane is in level flight.

iv. If there is deviation between the FY-20A horizontal position and the plane’s level flight, it may

cause the neutral value to be different between the Manual Mode and the auto Balance Mode.
This difference may result in the following:

Plane Connection Layout:

1) Normal / Traditional servo layout:

2) Plane without aileron servo:

3) Delta-winged plane servo:

For all fix wing aircrafts (including the traditional rudder, aileron and elevator planes, and planes with
aileron and elevator mixing, and so on) if the rudder is NOT used in any mixing function, you can have
two options ,as shown below:

1. Keep the FY20A rudder channel (RUD IN, RUD OUT) open (not used). Connect the Rudder servo

directly to your RC Receiver.

2. Connect your Receiver Channel 4 to FY20A (RUD IN) and

connect the rudder servo to RUD OUT.

Aileron-Elevator Mixing

For the following aircraft: Delta Wing with Elevator signal mixing
(e.g. Flying wing Elevon):
Differential Output is carried out by using a jumper as shown here. The jumper has to be installed
before powering ON. If you install it after powering ON, the mixing function will not take effect.

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FY-20A Pre-Flight Checking and Debugging
PRE-FLIGHT CHECK:

The following procedure explains how to check for correct servo control direction upon FY-20A
activation. You should also check that the FY-20A does not control the aircraft servos when in Mode 1
(Deactivated Mode).

STEP 1: DIAL ADJUSTMENT

Adjust the three dials on the FY-20A so that the arrow is in the middle, as shown below. Then
rotate all dials in one direction (does not matter which direction):