Futaba GYA352 User Manual
Rate gyro for models
AVCS RATE GYRO
INSTRUCTION
MANUAL
1M23N07408
Thank you for purchasing a GYA352 AVCS gyro.
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.
• This manual has been carefully written. Please write to Futaba if you feel that
any corrections or clarifications should be made.
1
FOREWORD
The GYA352 is a high performance, compact, and light weight
AVCS gyro developed for model airplane aileron, elevator, or
2
SET CONTENTS
The GYA352 comes with the following
accessories:
rudder control. Two of these surfaces (axis) can be controlled by
GYA352. Integrated sensor and control circuit simplifies mounting
in the aircraft.
Features
•Two axis control type (X-axis/Y-axis)
Two axis of aileron, elevator or rudder can be simultaneously
controlled by GYA352. ( For aileron, always use X-axis.)
•Built-in gyro mixing for Elevon/V-tail wing
•AVCS used
Forward, climb, descent, back, knife edge, and other flying attitudes are maintained even when the wind shifts. Therefore, since meeting rudder is almost
completely unnecessary, flying is easy. At the same time, the gyro automatically
corrects bad tendencies of the aircraft.
•SMM gyro sensor
Newly developed very low drift SMM (Silicon Micro Machine) gyro sensor
practically eliminates trim changes during flight.
•Remote gain and mode switching functions
Remote gain function lets you switch the gyro gain from the transmitter. AVCS
mode/Normal mode/Gyro OFF can also be switched from the transmitter.
•Integrated type, compact size, and light weight
Compact size (43x30x30.5mm) and light weight (49.5g) have been achieved by
the use of high density mounting technology.
•Conductive resin case improves EMC resistance (electrostatic, electromagnetic wave interference).
3
NAME AND FUNCTION OF EACH PART
•GYA352
GYA352 Ratings :
Servos :
•Mixing on/off switch (ALV)
Turns on or off the gyro mixing for Elevon/V-tail wing. When using the gyro mixng, this switch is set to the
•Monitor LED
Monitors the operating status of the GYA352. See
the table below for the display contents.
•Servo output connector
Connects the corresponding servo.
(X-axis output/Y-axis output)
•Control Gain trimmer
ON position. When not using the gyro mixng, this switch is set to the OFF position.
•Control selector switch (CNT.X)
Selects to match the flight control surface to be controlled (X-axis side). When using the GYA352 to
control the ailerons, this switch is set to the AIL position. When using the GYA352 to control the elevator
or rudder, this switch is set to the ELV position.
•Gyro direction of operation selector switch (DIR.X, DIR.Y)
Selects the direction of operation of the gyro. If the rudder moved when the fuselage was moved in the
gyro control axis direction and the rudder moved to cancel this movement, the direction of operation is
matched. If the aircraft is flown while the direction of operation is wrong, the gyro may apply reverse
rudder and is very dangerous.
(C GAIN)
Adjusts the steering signal controlled
variable. The effect of the rudder when
the gyro is turned on can be adjusted.
When the trimmer is turned clockwise,
the controlled variable increases.
(X-axis trimmer/Y-axis trimmer)
•Double-sided tape
(3 sheets)
•Mini screwdriver
(for adjustments)
(Integrated sensor / two axis control type AVCS rate gyro)
• Control system: Digital advanced PI (Proportional Integration) control
• Gyro sensor: SMM (Silicon Micro Machine) system vibration gyro
• Operating voltage: +4 to +6VDC
• Dimensions: 43 x 30 x 30.5mm
• Weight: 49.5g (including connector)
• Functions: Gyro operation direction switch, Mixing switch, Gyro gain
trimmer, and Control gain trimmer
Gyro performance largely depends on the servo used. The faster and
more responsive the servo, the higher the speed and the better the
sensitivity and performance of the gyro.
•Servo input connector
(black)
Connects to the corresponding servo
output connector of the receiver.
(X-axis connector/Y-axis connector)
•Gyro Gain trimmer (G GAIN)
Adjusts the gyro gain. Adjust the gain to the maximum value at which hunting does
not occur. The gain becomes “0” in the center. When Gain Switching connector is
connected in the receiver, the gain adjustment is made from the transmitter. In this
case, adjust within the “A” side. The value set with this trimmer becomes the
reference. The gain can be adjusted by changing the servo deflection angle
setting of the transmitter gain adjustment channel. When the gain adjustment is
made only this trimmer, adjust within the “N” side. In this case, the gyro operates
in the normal mode only.
(X-axis trimmer/Y-axis trimmer)
(Monitor LED display)
LED display Gyro operation status
Rapid flashing Displayed while data is being initialized at power ON. (green)
Steady light Shows that the gyro is operating in the AVCS mode.
Off Shows that the power is OFF, or the gyro is operating in the Normal
Slow flashing Displayed when a control signal is not input from the transmitter.
Double flash In the AVCS mode, displayed when the signal from the transmitter
Single flash Displayed when the AVCS function is reset, and a neutral signal is sent
•Red; X-axis operation, Green; Y-axis operation, Orange; (simultaneous)
mode.
deviates from the neutral signal memorized at the gyro. Also displayed
when a stick is operated.
to the servo. The LED flashes once when the gain selector switch was
quickly switched between the Normal and AVCS positions three or
more times and then left in the AVCS position, or when a transmitter
stick was quickly moved to the left and right three or more times. After
this display is performed, the servo moves to the neutral position. This
display also flashes when the control selector switch was moved.
•Gain switching connector (remote gain input)(red)
Gyro gain switching signal input connector. Connects to the receiver gain switching channel
output connector. The signal from this connector is also used to switch the AVCS and Normal
operation modes simultaneously with gain switching. Since this connector is a single signal
wire, do not pull on it forcefully.
(X-axis connector/Y-axis connector)
GYA352 operation modes
The GYA352 has two operations modes: AVCS mode and Normal mode.
Normal mode:
This mode performs general proportional control operation. For instance, it controls the gyro so that
changes are countered when the attitude of the aircraft is changed by cross-wind, etc.
AVCS mode:
This mode performs both proportional and integrated control operation. The difference between
Normal mode and AVCS mode operation is that whereas the Normal mode only counters changes in
attitude, the AVCS mode returns to the original controlled variable simultaneously with countering
changes in attitude. For example, during knife edge flying, aileron and elevator meeting rudder is
normally necessary, but in the AVCS mode, meeting rudder is performed automatically by the gyro.
Also, in the AVCS mode, high-speed control is possible, but when the usage method is incorrect,
unintended operation may be performed. Before use, gain a thorough understanding by reading the
Usage Precautions and Operation Instructions.
4
GAIN AND OPERATION MODE SETTING
The relationship between the travel adjustment functions (ATV,
AFR, END POINT) settings and gyro gain when the gyro gain is
switched using the transmitter switching channel is shown below.
Transmitter
ATV, etc. setting
(Forward or down)
(Back or up)
•When Gyro Gain trimmer is set to the "N" side, the gyro oper-
100%
70%
40%
0%
40%
70%
100%
When 100% set
(at the "A" side)
ates in the normal mode at both side of the switch directions.
Operation mode
Actual Gyro gain
50%
100%
25%
50%
0%
0%
Gyro
Gyro
OFF
OFF
0%
50% 25%
NORMAL OFF AVCS
100%0%50%
When 50% set
(Gyro Gain trimmer position)
(at the "A" side)
•This figure shows the case
when the gain setting channel
reverse function is set to
Normal. When this function is
set to Reverse, the switch
directions are reversed. (When
Futaba proportional set used)
Gyro OFF setting:
As shown in the figure, when the ATV rate of the gain setting channel is 40% or
less, the gyro gain becomes zero. When you want to turn off the gyro, set to this
range (40% or less).
AVCS mode gain setting:
(in case of "A" side of the Gyro Gain trimmer)
When the ATV_B rate is 40% or more, the gyro operates in the AVCS mode. The
actual gyro gain changes based on the Gyro Gain trimmer setting of the gyro
itself. When the Gyro Gain trimmer is set to 100%, the gyro gain becomes 100%
at 100% ATV rate and becomes 50% at 70% ATV rate. When the Gyro Gain
trimmer is set to 50%, when the ATV rate is 100%, the gyro gain becomes 50%
and when the ATV rate is 70%, the gyro gain becomes 25%.
Normal mode gain setting:
(in case of "A" side of the Gyro Gain trimmer)
When the ATV_A rate is 40% or more, the gyro operates in the Normal mode.
The gyro gain setting can be adjusted the same as in the AVCS mode.
When gain switching from transmitter function not used:
The gyro gain switching connector is not connected to the receiver. In this case,
when Gyro Gain trimmer is set to "A"/"B" side, the gyro operates in the AVCS/
normal mode severally. The gyro gain is set using the Gyro Gain trimmer.
5
OPERATION INSTRUCTIONS
Mount and adjust the GYA352 as described below.
Gyro Mounting Method
Make a gyro bed so that the bottom of the gyro body is perpendicular to the direction of the axis (X-axis, Y-axis) to be controlled and
securely install the gyro with the accessory double-sided sponge
tape at a position which vibrations are minimal.
•If this axis changes, the gyro also responds to the changes
of other axis.
•In order to raise attachment intensity, always fix two bottoms
of the gyro body to fuselage with two double-sided sponge
tapes.
Mounting example
•Aileron control
Aileron axis
Usage Precautions
•When taking off and landing, always switch to the Normal mode.
Taking off and landing in the AVCS mode is dangerous.
•We recommend that you use the rudder control gyro in the
Normal mode. In the AVCS mode, rudder operation is necessary when turning to prevent weathervaneing. Use the gyro in
the Normal mode unless you are an expert in rudder operation.
•When the gyro is ON, the servo operating angle increases.
Increase the travel width of the flight control surfaces so that
they will not strike the linkage even when the servo is operated
to its maximum deflection angle.
•Always use the miniature screwdriver supplied to
operate the GYA352 selector switches and trimmers.
Do not apply excessive force.
Rudder axis
•Rudder control
•Elevator control
Elevator axis
•When the gyro is used for aileron control,
always use the X-axis side and set
Control Selector switch to the "AIL" side.
Beginner setting
(When there is no vacant receiver channel)
Use this setting method when there is no vacant receiver channel.
Use the GYA352 in the Normal mode only.
Mounting to fuselage and initial setting
1. Gyro mounting
Mount the gyro to the axis you want to control in accordance with "Gyro
Mounting Method".
2. Gyro connection
• Connect to the servo.
• Connect to the servo.
• Connect to the receiver output
of the channel to be controlled.
• Do not connect.
• Connect to the receiver output
of the channel to be controlled.
• Do not connect.
3. Trimmer setting (Initial)
Set the X-axis and Y-axis Gyro Gain trimmers to about the
N50% position. Do not set them to the A side. Taking off
and landing in the AVCS mode is dangerous.
Set the X-axis and Y-axis Control Gain trimmers to about
the 100% position.
4. Controlled axis selection
When using the GYA352 to control the ailerons, set the
Control selector switch to the AIL position. When using
the GYA352 to control the elevators or rudder, set the
Control selector switch to the ELV position.
5. Operation mode selection
When using the gyro mixng for Elevon/V-tail wing, this switch is set to the
ON position. In this case, do not use the transmitter mixing function for
Elevon/V-tail wing.
In case of Elevon wing, always use the X-axis for the aileron control and
the Y-axis for the elevator control. In case of V-tail wing, always use the
X-axis for the rudder control and the Y-axis for the elevator control. The
linkage of two servos must be symmetrical. If not, the gyro will operate in
the wrong direction and result in a dangerous situation.
When not using the gyro mixng, this switch is set to the OFF position.
Control selector switch (CNT.X)
Mixing on/off switch (ALV)
6. Power ON procedure
Turn on the transmitter power, then turn on the receiver and gyro power.
After the gyro power is turned on, initialization is automatically performed
for about three seconds. Never move the aircraft during this period.
During initialization, the gyro monitor LED flashes green.
7. Gyro direction of operation check
Tilt the aircraft about the controlled axis, and check if the gyro applies
rudder in the direction opposite the direction of tilt.
If the rudder moves in the opposite direction switch the gyro direction of
operation selector switch.
Gyro direction of operation
selector switch
N50% 100%
N50% 100%
DIR.X
DIR.Y
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