Futaba GYA440 User Manual

1M23N30702

Rate Gyro for Airplanes
Elevator or Rudder use

I

NSTRUCTION MANUAL

I

For RC models

Before using your new gyro, please read this manual thoroughly
and use the gyro properly and safely. After reading this manual,
store it in a safe place.

• No part of this manual may be reproduced in any form without prior
permission.

• The contents of this manual are subject to change without prior notice.

• Futaba is not liable for any potential damage (accidental or otherwise)
that may occur after installation.

NSTRUCTION MANUAL

Features of GYA440

● Dedicated airplane setting

Stabilizes ight, even with hard-to-control scale models.

● Compatible with elevator or rudder control

The GYA440 can choose and use an elevators or a rudder.

● Remote gain function

The remote gain function allows the sensitivity of the gyro to be
adjusted from the transmitter and the mode switching function allows
AVCS/NORMAL gyro mode switching. Also the gain can be adjusted by
the trimmer on the GYA440.

● Integrated type, compact size and light weight

High-density mounting technology makes the GYA440 compact (20.5
x 20.5 x 11 mm) and lightweight (3.7 g).

● Easy setup

Basic settings let you be ight-ready in an instant.

● Supporting the S.BUS/S.BUS2 connection

Only one wire connection to the receiver can operate the GYA440.

Name and Function of Each Part

Elevator/Rudder

●

selector switch

Gyro direction

●

switch

Trimmer (Limit/

●

GAIN)(Digital
/ Analog servo
function)

Operation status Color Display Remarks

1. No servo pulse /
sensor error

2. Start of initialization

3. End of initialization

4. Turn

5. Neutral deviation

6. Gyro sensitivity zero

7. Switch switching

. Low Battery

8

Port 3 (Elevator/Rudder servo output)

●

Port 2 (Gyro sensitivity input)

●

Monitor LED display

Red 3 flash

Green Fast blink

Red/

Green/

Orange

Red/

Green

Orange Slow blink

－

Green One blink

Red One flash

Steady

light

Fast blink

OFF

Port 1 (S.BUS input/

●

Elevator/Rudder servo
input)

LED

●

Servo

Mode

Normal

When power drops to 3.8V

Digital Analog

AVCS Red Red

Orange Green

Right (Green)

Left (Red)

When stick operated

Each switching

or less

Thank you for purchasing the GYA440 airplane gyro. Compact
and lightweight, the GYA440 is designed to control the elevators
(pitch axis) or rudder (yaw axis). Features include simple set-up
and S.BUS/S.BUS2 connectivity.

GYA440 Ratings:

(Integrated sensor type rate gyro)

• Gyro sensor: MEMS vibrating structure gyro

• Operating voltage: DC4.0V to 8.4V

• Current drain: 30mA (excluding a servo)

• Operating temperature range: -10ºC to +45ºC

• Dimensions: 20.5 x 20.5 x 11.0mm (except protrusion)

• Weight: 3.7g

• Functions: (1) Gyro sensitivity trimmer, (2) Monitor LED, (3) CH change
elevator or rudder, (4) S.BUS/S.BUS2 compatibility, (5) Digital/Analog
servo function

Set Contents

The following items are supplied with the GYA440:

Mini screwdriver

GYA440

Extension cord: (Black)

Sensor tape

Magic strap (for clamping the wiring)

WARNING

Failure to follow these safety precautions may result in severe injury
to yourself and others.

Check that there is sufficient transmitter battery capacity for flight.

• Determine the operating time of the receiver, gyro, and servo battery in the adjust-

ment stage and decide the number of ights with a margin to spare.

Analog servos cannot be used while in "digital servo" mode.

• Analog servos may break down if "digital servo" mode is selected.

Do not operate the airplane and transmitter sticks for about 3-5
seconds after turning on the GYA440 (When shared with the re­ceiver).

• GYA440 initialization and neutral position reading. The GYA440 is initialized when
the power is turned on. In the AVCS mode, the neutral position is also read at the
same time. If initialization ends normally, the operator is informed by two repetitive

movements of the servo to the left and right (a little).

Always check the direction of operation of the gyro.

• Attempting to y with the operating direction reversed is extremely dangerous. Al­ways check your gyro's direction to ensure safe ights.

Do not strike the gyro with a hard object. Do not drop it onto a con-

crete surface or other hard floor.

• The sensor may become damaged during strong impacts.

Do not use trims or mixing in AVCS mode.

• In the AVCS mode all corrections are made by the gyro. Therefore, if trimming and
mixing, are turned on, operation will be the same as deviating from the neutral po­sition.

Do not use the GYA440 for applications other than RC airplanes.

•This gyro is designed for RC airplanes only. Do not use it for other applications.

Do not place gyro near heating equipment (engine, motor, ESC,
battery, servo, etc.).

•Always allow the gyro to adjust to the surrounding environmental temperature be­fore ight. A large temperature change during use will cause drift and other opera-

tional issues.

Extension cord: (Red)

Connection

Extension cord: (Black)

Elevator /Rudder CH

Receiver

Gyro sensitivity CH

Gyro gain CH(Receiver)←connect→Port2(GYA440)
Remote gain effective. Trimmer(GYA440) becomes LIMIT.

Gyro gain CH(Receiver)←It does not connect→Port2(GYA440)
Remote gain is invalid. Trimmer(GYA440) becomes GAIN.

To port 1

To port 2

Accessory connector (Red)

To port 3

GYA440

Extension cord: (Black)

S.BUS Receiver

S.BUS/S.BUS2 port

Elevator(Rudder)

servo

S.BUS Connection

To port 3

To port 1

GYA440

Elevator (Rudder) servo

At S.BUS/S.BUS2 operation, the channels are fixed as shown in the
table below. Match the transmitter channels to these.

Function Channel

Elevator CH2

Rudder CH4

Gyro sensitivity (Elevator) CH7

Gyro sensitivity (Rudder) CH8

S.BUS 3-axes Connection Example

S.BUS connectivity minimizes wiring. The GYA440
and GYA441 can be connected by one 3-way hub. The
aileron, elevator, and rudder servos are output from
the gyro. Standards servos can also be used. When an
R6303SB is used the CH switching mode is set to group

7. The normal group 7 CH outputs are CH3, CH11, and

This is a three axes
connection example. The
aileron uses a GYA441 and
the receiver is an R6303SB.

S.BUS Receiver

S.BUS/S.BUS2 port

GYA441 (Sold separately)

GYA441 (Sold separately)

GYA440

Aileron servo

Elevator servo

Rudder servo

CH12. CH3 is the throttle channel and CH11/CH12 are
spare channels.

The transmitter function settings are shown below. A
total of 9 channels are used with 3-axes gyro control.

Function

Aileron CH1

Elevator CH2

Rudder CH4

2nd aileron CH6

2nd elevator CH9

Gyro sensitivity

(aileron)

Gyro sensitivity

(elevator)

Gyro sensitivity

(rudder)

GYA441

(Aileron)

CH5

GYA441

(Elevator)

CH7

GYA440

(Rudder)

CH8

Mounting to the Chassis

The gyro is very sensitive to vibration. Securely mount it with the included double-sided sponge tape at a position where vibration is
minimal and the gyro is perpendicular to the axis to be controlled. Since double-sided tape will not stick to balsa, make a smooth sur­face by cementing a smooth plastic sheet. to the frame and securely attach the gyro with double-sided tape. Provide a surplus in the
wiring and bundle the wiring with the included magic strap so that it will not interfere with the rod.

Sensor tape

Degrease and stick

＜ Elevator mounting ＞

Gyro

Controlled axis (pitch axis)

90°

Flat surface of the fuselage to which
sensor tape easily sticks
(Sensor tape does not stick to balsa)

＜ GYA440 elevator mounting ＞
The turning direction which xes the

gyro can be any direction up to 360°
relative to the pitch axis.

＜ Rudder mounting ＞

Aileron control
(GYA441)

Elevator control

Rudder control

Servo

0%

Link the servo in accordance with the kit instruction manual.
Adjust the linkage rod so that the trim amount is as small as pos­sible.

Digital/Analog servo selection

Selection of an analog and digital servo is performed in a limit
trimmer's setting position.

A limit trimmer's motion is as follows.
Digital servo → A trimmer is adjusted by the Right rotation from

the middle point.
Analog servo → A trimmer is adjusted by the Left rotation from

the middle point.
The amount of limits -- the halfway point -- the minimum -- it will

become the maximum quantity if it is made to rotate to max, re­spectively. The check of operational mode is discriminable in the
display color of LED. The stability of digital-servo mode of a ight
increases in order to perform a high-speed control action.

Selection of digital /analog servo
is chosen towards a trimmer turning.

Digital-servo mode:
LED Orange

LIMIT
GAIN

Analog-servo mode:
LED Green

When a remote gain function is o󱐯, it becomes only analog servo
mode. A trimmer becomes only for gain.

(Digital-servo use is possible)

*When you use an analog servo, please be sure to set to ana-

log servo mode. If it sets to digital-servo mode and it is op­erated, there is a danger that a servo will be destroyed.

[Limit position]

Limit position
of digital servo

70%

Limit position
of analog servo

100%

100%

130%

LIMIT
GAIN

130%

Preight Adjustments

Setup before a ight [ Remote gain use ]

Adjust the gyro sensitivity at the transmitter.

At S.BUS connection or when gyro port 2 and the gyro sensitivity CH

of the receiver are connected

Use the Elevator/Rudder selector switch to select elevator or

1

rudder. (Elevator: ELE Rudder: RUD)　　　　

Turn on your transmitter's power. Set the gyro sensitivity to about

2

30% at the normal side (minus rate side) in accordance with the

transmitter instruction manual. 30% of normal sensitivity will be about

-60% at the rate of the sensitivity CH so that a next graph may be seen
and understood.

Turn on the receiver power. When the gyro starts, the LED ashes

3

green and initialization begins. When initialization ends, the
servo performs reciprocating operation to the left and right. (a little)
This places the gyro into the ready state. During initialization, secure
the fuselage so that it will not move and fix the transmitter stick at
the neutral position. Initialization takes about 3-5 seconds after the
receiver operates. After initialization, the LED lights green/orange. If
the neutral position has changed, the LED will slowly blink orange.
In this case, restart the gyro. Move the stick and check that the servo
operates

4

position at which there is no interference with the linkage.

.

Move the stick to the maximum left and right. Adjust the gyro

limit trimmer so that the servo operating angle is at the maximum

Gyro sensitivity zero --- LED OFF

AVCS side --- LED red

NORMAL side --- LED green

＜Limit trimmer Adjustments＞

D/R (UP side)

Elevator stick up
/down to full

In the case of rudder control, move the gyro direction switch and

5

adjust the direction of operation of the gyro so that the rudder
move all the way to the right when the airplane is turned to the left. In
the case of elevator control, move the gyro direction switch and adjust
the direction of operation of the gyro so that the elevator servo moves
in the down direction when the airplane is moved in the up direction.
If the direction of operation of the gyro is incorrect, ight will become
impossible, so please make sure the settings are correct.

Tilt the airplane to the
up on the ground and
check that the elevator
operate to the down.
(In the case of elevator
control)

Tilt the airplane to the left on
the ground and check that the
rudder operate to the right. (In
the case of rudder control)

Digital

LIMIT
GAIN

Analog

Analog

Limit trimmer
Adjustments

● Trimmer operation

*Make trimmer adjust­ments gently by using the
included mini screwdriver.

（

）

Elevator

It adjusts to the
maximum operation of
linkage.

[ When remote gain function is off ]

Adjust the gyro sensitivity with the GYA440 trimmer.

Do not use the AVCS mode.

All remote gains are effective at S.BUS connection. When port 2 is not
connected when S.BUS is not used, remote gain is inhibited. In this case,
the limit trimmer is automatically changed to gyro sensitivity setting
trimmer.

(Limit position is xed at operating angle left and right 55°. A servo is
xed to analog mode.)

In this case,

*

of di󱐯ering in a procedure are lost. And as shown in a gure, gain is
adjusted of the trimmer of GYA440.

A gain trimmer's work

＜

AVCS 50%

0%

gain setup with a transmitter and

2

＞

AVCS 100%

LIMIT
GAIN

NORMAL 100%NORMAL 50%

NORMAL 30%

limit adjustment

4

First, we recommend to

start with NORMAL 30%.

LIMIT
GAIN

Gyro Sensitivity and AVCS Switching

When the remote gain function is used normally and AVCS
mode switching is performed in accordance with the direction of
operation of the transmitter's remote gain channel. At the + rate
side, the AVCS mode is selected and at the – rate side, the NOR­MAL mode is selected. The sensitivity is changed by adjusting
the end point rate. If the transmitter has a gyro sensitivity set­ting mixing function, the sensitivity setting is performed directly.

When the remote gain function is not used, the clockwise di­rection from the center of the sensitivity setting trimmer is the
AVCS mode (not used) and the counterclockwise direction is the
NORMAL mode. At the center position, the sensitivity becomes
zero. When the trimmer is turned fully to the left or right, the
sensitivity becomes 100%.

The sensitivity setting criteria by end point is shown in the
gure below. The sensitivity becomes zero between end point

-40% to +40% and becomes 100% at end point 100%.

GAIN CH

＜

100%

Gain

50%

-70%-100%

-40%

0%

NORMAL side（LED : GREEN）

Refer to the transmitter instruction manual and set the end
point. When AVCS is used, setting the 3-positions switch to the
sensitivity CH (there are types which cannot be set by transmit­ter) and setting it as shown above is recommended. In the case
of a 2-positions switch, inhibiting the gyro at 0% sensitivity such
as NORMAL mode and sensitivity 0% and AVCS mode and 0%
sensitivity is safe.

Trimmer movement when the
remote gain function is not used
(when S.BUS is not used and port
2 is not connected) . Please do
not use AVCS, when you do not
use remote gain. Because, neutral
memory cannot be performed.
And taking off and landing being
dangerous.

＞

AVCS side（LED : RED）

+70% +100%

+40%

End point rate

50%

100%

AVCS

GAIN 0％

NORMAL

When AVCS is used we
recommend that the
sensitivity CH be set to
the 3-position.

AVCS 50%

0%

AVCS 100%

LIMIT
GAIN

NORMAL 100%NORMAL 50%

direction. The gyro sensitivity is different depending on the area of
the aircraft rudder, air speed, and gyro used. Initially try changing
the sensitivity in 5% steps. If hunting is excessive, the aircraft may be
damaged. Hunting tends to stop when the airspeed is lowered.

Servo Operation on the Ground

If the stick is moved when the airplane is on the ground, the ser­vo will move to the limit position. In the AVCS mode, the servo
will not return to the neutral position even if the stick is set to
the neutral position, but this is normal.

If the stick is moved fully to the left or right three or more times
within one second, the servo will temporarily return to the neu­tral position.

AVCS/NORMAL Modes

The gyro has two operation modes: NORMAL mode and AVCS
mode. In the AVCS mode, angle control is performed at the same
time as NORMAL mode rate (rotating speed) control. In the AVCS
mode, the neutral keeping force is stronger than the NORMAL
mode and the flight attitude of the aircraft is forcefully main­tained. During knife-edge flying, idiosyncrasies of the aircraft
when climbing will be compensated automatically. On the other
hand since the rudder follows when the aircraft stalls, pay spe­cial attention to the elevator axis. To be safe, switching to the
NORMAL mode when taking o󱐯 and landing is recommended.

When GYA440 used at the rudder of airplane

In AVCS operation

Mode

AVCS is working

properly during

a cross wind.

Cross

Cross
wind

wind

In NORMAL operation

NORMAL in a cross

The tail will drift.

Flight Adjustment

Adjust the transmitter and gyro while repeatedly taking o󱐯 and
landing and with the aircraft on the ground.

Transmitter adjustments must not be made while ying

If no left rudder input
is given, the machine

will drift to the right.

because it is dangerous.

Fly the aircraft and trim it by turning o󱐯 the gyro at 0% sensitivity

1

or in the NORMAL mode. After trimming, switch the gain switch
between 0% sensitivity (or NORMAL mode) and the AVCS mode three
times at an interval of within one second and then set the gain switch
to the AVCS mode position. This memorizes the AVCS mode neutral
trim position at the gyro. In the AVCS mode, do not perform trimming
during ight.

Adjust the gyro sensitivity so that hunting (deflection of the

2

aircraft in small increments) does not occur in the control axis

FUTABA CORPORATION

1080 Yabutsuka, Chosei-mura, Chosei-gun, Chiba-ken, 299-4395, Japan

Phone: [phone], Facsimile: [phone]

©FUTABA CORPORATION 2016, 1 (1)

If it starts rightward

A head turns to a

direction of movement

automatically.

If it starts rightward

Mode

wind.

Cross
wind