FUTABA GYA352 User manual

• No part of this manual may be reproduced in any form without prior permis-
sion.
• 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.
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.
1M23N07408
FOREWORD
1
The GYA352 is a high performance, compact, and light weight
AVCS gyro developed for model airplane aileron, elevator, or
rudder control. Two of these surfaces (axis) can be controlled by
GYA352. Integrated sensor and control circuit simplifies mounting
in the aircraft.
Servos :
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.
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 main-
tained 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, electro-
magnetic wave interference).
SET CONTENTS
2
•GYA352
•Double-sided tape
(3 sheets)
The GYA352 comes with the following
accessories:
•Mini screwdriver
(for adjustments)
GYA352 Ratings :
(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
NAME AND FUNCTION OF EACH PART
3
•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)
(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
mode.
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
deviates from the neutral signal memorized at the gyro. Also displayed
when a stick is operated.
Single flash Displayed when the AVCS function is reset, and a neutral signal is sent
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.
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.
INSTRUCTION
MANUAL
Rate gyro for models
AVCS RATE GYRO
•Red; X-axis operation, Green; Y-axis operation, Orange; (simultaneous)
•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
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.
•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)
•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)
•Control Gain trimmer
(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)

GAIN AND OPERATION MODE SETTING
4
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.
•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.
OPERATION INSTRUCTIONS
5
Mount and adjust the GYA352 as described below.
Gyro Mounting Method
Make a gyro bed so that the bottom of the gyro body is perpendicu-
lar 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.
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 neces-
sary 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.
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
• Do not connect.
• Connect to the receiver output
of the channel to be controlled.
• Connect to the servo.
Control selector switch (CNT.X)
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.
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
•When Gyro Gain trimmer is set to the "N" side, the gyro oper-
ates in the normal mode at both side of the switch directions.
100%
40%
70%
0%
40%
100%
100%
50%
0%
50%
25%
70% 50% 25%
0%
0%
100%
0%
50%
Operation mode
Transmitter
ATV, etc. setting Actual Gyro gain
(Forward or down)
(Back or up)
Gyro
OFF
Gyro
OFF
NORMAL OFF AVCS
When 100% set
(at the "A" side)
When 50% set
(at the "A" side)
(Gyro Gain trimmer position)
Mounting example
•Aileron control
Aileron axis
Elevator axis
•Elevator control
•Rudder control
Rudder axis
•When the gyro is used for aileron control,
always use the X-axis side and set
Control Selector switch to the "AIL" side.
•Connect to the servo.
•Do not connect.
•Connect to the receiver output
of the channel to be controlled.
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.
N50% 100%
N50% 100%
Mixing on/off switch (ALV)
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.
DIR.X
DIR.Y

Standard Setting
(Setting using all GYA352 functions)
This standard setting controls gain switching and AVCS/ Normal
gyro operation mode switching from the transmitter.
However, two vacant channels are necessary to switch the gain and
operation mode. When there are not enough vacant channels, do not
connect the gain switching connector and operate the gyro in the
Normal mode only. The gain of the gyros of two axis can also be
switched simultaneously using a branch cord.
Mounting to fuselage and initial setting
1 Gyro mounting
Install the gyro to the axis to be controlled in accordance with "Gyro
Mounting Method".
2 Gyro connection
•Connect to the gain switching
channel.
•Connect to the servo.
When there is no vacant channel that can be used for gain switching,
"Standard setting" cannot be performed. See "Beginner setting".
When there is one vacant channel only, use a branch cord to simulta-
neously switch the gain of two axis.
(Gain setting with T9ZAP example)
The following describes how to use vacant channels 7 and 8 to switch the
gain of the X-axis and Y-axis.
7. Power ON procedure
Turn on the transmitter power, then turn on the receiver and gyro power.
Initialization is performed automatically for about three seconds after the
gyro power comes on. Do not move the aircraft during this period. During
initialization, the gyro monitor LED flashes green. When the gain selector
switch is set to the AVCS position, the monitor LED changes to a steady light
(X-axis; red, Y-axis; green.) When the gain selector switch is set to the
Normal position, the LED goes off.
8. Gyro operation direction check
Tilt the aircraft about the control axis, and check if the gyro moves in the
direction opposite the tilt direction.
If the gyro moves in the opposite direction, switch the Gyro direction of
operation selector switch.
Flight adjustments
1. 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.
2. Trimming
Fly and trim the aircraft.
If there is a large mechanical deviation, correct the linkage. Connect the
linkage so that the servo horns are as close to the center position as
possible and the transmitter trimmers are also at the center position.
3. Gyro gain adjustment
When the servo hunts, the gyro gain is too high. Lower the
gain with the Gyro Gain trimmer until the hunting stops. The
gyro will display best performance at a gain just before
hunting occurs. Perform trimming by flying the aircraft
repeatedly.
4. Rudder effect adjustment
Use the transmitter steering angle adjustment function to
adjust the rudder effect.
However, when the rudder effect is substantially different
from that when the gyro was not mounted, adjust it with the
Control Gain trimmer.
When the gyro is turned on, the rudder will feel sluggish. Adjust the
control gain so that the rudder effect matches the rudder effect when the
rudder stick is set to its maximum position. When the control gain is
increased, the rudder effect increases.
Gyro Gain
trimmer
(G GAIN)
Control Gain
trimmer
(C GAIN)
•Connect to the servo.
•Connect to the receiver output
of the channel to be controlled.
•Connect to the receiver output
of the channel to be controlled.
•Connect to the gain switching
channel.
3. Trimmer setting (Initial)
Set the X-axis and Y-axis Gyro Gain trimmers to the A100%
position. 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.
6. Gain setting
Set the gain as described below.
Control selector switch (CNT.X)
Mixing on/off switch (ALV)
A100% 100%
A100% 100%
(Gain setting with T8UAPS or T9CAP example 2)
The following describes how to use CH5 to switch the X-axis and Y-axis
gains simultaneously. Connect the X-axis and Y-axis Gain switching
connectors to the receiver CH5 output using a branch cord.
OFF
NORMAL
(T8UAPS)
(CH7 knob)
(CH8 knob)
(SW-E)
(SW-E)
(T9CAP)
NORMAL
AVCS
OFF
AVCS
1.Call the transmitter P-MIX1 screen, and
make the following settings:
- Activate P-MIX1.
- Set master channel to OFS(OFST).
- Set slave channel to CH7(AUX1).
- Set mixing rate to +70%.
- Select switch SW-E.
- Select switch direction DOWN.
2.Call the transmitter P-MIX2 screen, and
make the following settings:
- Activate P-MIX2.
- Set master channel to OFS(OFST).
- Set slave channel to CH7(AUX1).
- Set the mixing rate to -70%.
- Select switch SW-E.
- Select switch direction UP.
3.Lock the transmitter CH7 knob
in the 0% position. This sets
the X-axis gyro gain to 50%.
•When SW-E is in the forward,
center, and backward positions, the
GYA352 operates in the AVCS,
OFF, and Normal modes,
respectively.
4.Call the transmitter P-MIX3 screen, and
make the following settings:
- Activate P-MIX3.
- Set master channel to OFS(OFST).
- Set slave channel to CH8(AUX2).
- Set mixing rate to +70%.
- Select switch SW-E.
- Select switch direction DOWN.
5.Call the transmitter P-MIX4 screen, and
make the following settings:
- Activate P-MIX4.
- Set master channel to OFS(OFST).
- Set slave channel to CH8(AUX2).
- Set mixing rate to -70%.
- Select switch SW-E.
- Select switch direction UP.
6. Lock the transmitter CH8 knob
in the 0% position. This sets
the Y-axis gyro gain to 50%.
•When SW-E is in the forward,
center, and backward positions, the
GYA352 operates in the AVCS,
OFF, and Normal modes,
respectively.
(T8UAPS) (T9CAP)
1.Call the transmitter CH5 ATV(E.POINT)
screen and make the following setting:
Set the rate of both directions of the CH5
switch to 70%. This sets the gyro gain to
50%.
•In the switch forward position, the gyro operates in the AVCS mode and in
the switch backward position, the gyro operates in the Normal mode.
+T1
+J1
AIL
+T3
+J3
ELE
+T2
+J2
THR
+T4
+J4
RUD
+SF
GEA
+LD
FLP
+SE
AU1
+SE
AU2
END
SEL
CTR
TRM
FUNCT CTRLFUNCT CTRL
ENDAIL ELE THR RUD GEA FLP AU1 AU2
ATVATV
NXT
NORMAL
AU1
70 %
70 %
: MODE
: CHANNEL
: RATE A
AINPUT
SRV
B
: RATE B
OFF
NORMAL
AVCS
SW(E)
1.Call the transmitter function control
functions screen, and make the following
settings:
- Set switch SE to AU1(CH7) and
AU2(CH8).
2.Call the transmitter ATV function screen,
and make the following settings:
- Select AU1(7CH) and AU2(8CH) and
set both RATEA and RATEB to 70%.
This sets the gain of the X-axis and Y-axis to 50% each.
•When SW(E) is set to the forward, center, and backward
positions, the GYA352 operates in the AVCS, OFF, and
Normal modes, respectively.
Gyro direction of operation
selector switch
DIR.X
DIR.Y
(Gain setting with T8UAPS or T9CAP example 1)
The following describes how to use CH7 to switch the X-axis gain and
CH8 to switch the Y-axis gain.

Control gain
trimmer (C GAIN)
Flight adjustment
1. Power ON procedure
Turn on the transmitter power, then turn on the receiver and gyro power.
Initialization is performed automatically for about three seconds after the
gyro power comes on. Do not move the aircraft during this period.
2. Trim adjustment
Set the gyro gain switch to the Normal or OFF position. The monitor LED
goes off. Fly and trim the aircraft in this state.
When the mechanical deviation is large, correct the linkage. Connect the
linkage so that the servo horn and transmitter trims are in the center
position.
3. Gyro gain adjustment
When the servo hunts, the gyro gain is too high. Lower the gyro gain until
the hunting stops. The gyro displays top performance at a gain just before
hunting begins. Perform trimming by flying the aircraft repeatedly. Adjust
the gain by raising and lowering the transmitter ATV or mixing rate.
4. Rudder effect adjustment
Use the transmitter deflection angle adjustment function to
adjust the rudder effect.
However, when the rudder effect is substantially different
from that when the gyro is installed, adjust it using the control
gain trimmer.
When the gyro is turned on, the rudder will feel sluggish. Adjust the
control gain to match the rudder effect when the stick is set to its maxi-
mum position. When the control gain adjustment amount increases, the
rudder effect increases. Adjust the linkage so that use is possible at a
transmitter deflection angle setting of 70% or more.
5. AVCS side neutral data memorization
The neutral data can be memorized by following process. After landing the
aircraft, set the rudder stick to the neutral position and rapidly switch the
transmitter gain switch between the AVCS and Normal positions at least
three times at an interval of within one second and then set the gain switch
to the AVCS position. In this case, the monitor LED flashes once to show
that memorization is complete. The neutral data can also be memorized by
setting the gain switch to the AVCS position and turnning on the gyro
power again. When using flight conditions, verify that the gyro monitor
LED lights under all the flight conditions used. If the LED flashes twice,
trim of that flight condition has changed. Repeat transmitter trim adjust-
ment. This ends AVCS side setting.
6. Switch to the AVCS or Normal mode, as desired.
In the AVCS mode, meeting rudder is seldom necessary because trim
changes during knife edge and upside-down flight are compensated for by
the gyro. Conversely, when the aircraft enters a stall condition in the low
speed state, the gyro continues to apply correction rudder and the aircraft
may enter an unintended attitude. To avoid stalling in such a state, return
to normal attitude as soon as possible by increasing engine power and
applying reverse rudder, or switch the gyro to the Normal mode.
Fuselage Maintenance
Precautions
Do not turn the sensitivity trimmer with
too much force.
The trimmer may break. Always use the miniature
screwdriver supplied to make adjustments.
Service the fuselage with a little vibration
as possible.
Fuselage vibration has a very adverse effect on gyro
performance.
Mounting Precautions
Always use the accessory sensor tape to install
the gyro to the fuselage.
This is necessary to securely fasten the gyro to the fuselage
so that operation of the gyro does not transmit unwanted
fuselage vibrations directly to the sensor.
When mounting the gyro, provide a little
surplus so that the gyro connection cables
are not too taut.
If the gyro cables are too taut, the gyro will not display its
full performance. If the gyro peels, control will be lost and
result in a dangerous situation.
When using the gyro with a airplane, install
the GYA352 at least 10cm from the drive
motor and at least 2 cm from the servo.
The drive motor etc. generates strong electromagnetic
noise. This noise may interfere with the gyro sensor and
cause erroneous operation.
Mount the GYA352 so that metals or other
conductive objects do not touch the gyro
case.
The GYA352 uses a conductive resin case to reduce
electromagnetic interference. Because the surface of the
case is conductive, metal objects may cause a short circuit.
Insert the connectors fully.
If a connector works loose due to vibration during flight,
control may be lost and result in a dangerous situation.
Always check the direction of operation of
the servos.
If you attempt to fly the model when a servo operates in the
wrong direction, the fuselage will spin in a fixed direction
and enter an extremely dangerous state.
Operation Precautions
Never move the fuselage for about 3 sec-
onds after turning on the gyro power. (when
using in the AVCS mode)
Since the data inside the gyro is automatically initialized
as soon as the power is turned on, if the fuselage is
moved, the neutral position will change. If this occurs,
turn the power off and on again. When turning on the
power, set the transmitter switch to the AVCS position
FUTABA CORPORATION
Makuhari Techno Garden Bldg., B6F 1-3 Nakase, Mihama-ku, Chiba 261-8555, Japan
Phone: [phone] Facsimile: [phone]
Special Markings
Pay special attention to the safety at the parts of this manual that are indicated by the following marks.
Mark Meaning
Procedures which may lead to a dangerous condition and cause death or serious injury to the
user if not carried out properly.
Procedures which may lead to a dangerous condition or cause death or serious injury to the
user if not carried out properly, or procedures where the probability of superficial injury or
physical damage is high.
Procedures where the possibility of serious injury to the user is small, but there is a danger of
injury, or physical damage, if not carried out properly.
Symbol: ; Prohibited ; Mandatory
When using the gyro in the AVCS mode,
turn off mixing.
For example, if elevator down mixing is used by the air
brake, the gyro will judge that an elevator down signal
was received and will cause the aircraft to dive. In the
AVCS mode, the gyro automatically changes the trim
and, therefore, these mixings are unnecessary. When
mixing is necessary, set so that the gyro enters the
Normal mode when mixing is ON.
Check the operating time of the receiver,
gyro, and servo batteries at the adjust-
ment stage and decide the number of
remaining flights while allowing a margin.
and turn on the transmitter power switch, then turn on
the gyro power.
Do not operate the trim while flying in the
AVCS mode.
When the power is turned on, the GYA352 assumes that
the stick is in the neutral position. If the trim is moved
during flight, the neutral position will change.
Avoid sudden temperature changes.
Sudden temperature changes will cause the neutral
position to change. For instance, do not fly the model
immediately after removing it from inside a heated
vehicle in the winter and an air conditioned vehicle in
the summer. Let the model stand for about 10 minutes
to allow the temperature inside the gyro to stabilize
before turning on the power. Also, consider sudden
temperature changes when the gyro is exposed to direct
sunlight or is installed near the engine. Take measures
so that the gyro is not exposed to direct sunlight.
Do not stall the aircraft.
When the aircraft enters the stall condition, and the gyro
tries to maintain its original attitude by applying full
rudder. This results in assisting the stall. If the nose
remains up and the aircraft stalls when landing, etc., the
gyro will try to maintain that attitude by applying more
up elevator.
Do not use the AVCS mode when taking
off and landing.
From the standpoint of the operation characteristics,
taking off and landing in the AVCS mode is dangerous.
When taking off and landing, use the gyro in the normal
mode.
Using AVCS correctly
The AVCS type gyro controls the attitude of the aircraft by constantly
comparing the transmitter operation signals and the gyro internal
reference signal (transmitter neutral signal). Therefore, for the AVCS
function to operate normally, the rudder neutral signal must be memo-
rized at the gyro before flight.
Neutral signal memorization
There are two methods of memorizing the neutral signal.
[Method 1] When the gyro power is turned on, the signal received
from the transmitter at that time is assumed to be the neutral signal
and is memorized at the gyro. The gyro is normally used in this state.
[Method 2] The neutral position can also be memorized by rapidly
switching the transmitter gain switch between the AVCS and Normal
positions at least three times at an interval of within one second. In
this case, the monitor LED flashes once to show that memorization is
complete.
When the trim was changed during flight, the memorized neutral
position can be updated to the current neutral position by repeating
this operation. When this performing this operation, kept the stick in
the neutral position.
Neutral check method
In the AVCS mode, the servo does not return to the neutral position
even though the stick is returned to neutral. When you want to check
the servo neutral position during linkage neutral check, etc., set the
gain switch to the Normal position, or quickly move the transmitter
stick to the left and right at least three times and immediately return
the stick to the neutral position.
Dead zone of servo operation
A dead zone is produced in servo operation relative to stick operation.
However, this is because the stick control gain rises and is not an
abnormality.
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