Futaba GY470 Rate Gyro for Helicopters Instruction Manual

Futaba GY470 Rate Gyro for Helicopters

Features of of GY470

• Remote gain function and mode switching function
  You can adjust gain from the transmitter by using the remote gain function. Gain can also be adjusted with the trimmer on the GY470. The mode switching function allows AVCS/NORMAL gyro mode switching.

• Integrated, compact,and light weight
  Compact size（20.7×20.7x11mm）and light weight（3.7g） realized by high density mounting technology.

• Easy setup
  The GY470 can be used immediately with minimum setup.

• Supporting the S.BUS/S.BUS2 connection
  Only one wire connection to the receiver can operate the GY470.

GY470 Ratings: (Integrated sensor type rate gyro)

• Gyro sensor: MEMS vibrating structure gyro
• Operating voltage: DC4.0 V to 8.4 V
• Current drain: 30 mA (excluding a servo)
• Operating temperature range: -10 ºC to +45 ºC
• Dimensions: 20.7 x 20.7 x 11.0 mm (except protrusion)
• Weight: 3.7 g
• Functions: Sensitivity trimmer. LED monitor. Servo selection (1520 uS, 760 uS). S.BUS/S.BUS2 connection.

Functions

Monitor LED display

State| Color| Move| Reference
1. GY470 Power ON| Orange| 2 blinks|
2. No servo pulse / Error| Red| Slow blink|
3. Signal input from receiver| Green| Fast blink|
4. Sensor initialization| Red/Green| ON| AVCS (Red)

Normal (Green)

5. Turn| Red/Green| Fast blink| Right (Green) Left (Red)
6. Neutral offset| Orange| Slow blink| Stick operation
7. Gain off| －| OFF|
8. Switch operation| Green| One blink| Each time of switch operation
9. Low battery| Red| One flash| Less than 3.8 V

Thank you for purchasing a GY470 gyro, a rate gyro for RC helicopters. GY470 is a lightweight micro gyro developed for RC helicopter rudder (yaw axis) control. It can be used with mininum setup and includes an S.BUS/S.BUS2 port.
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 oth-erwise) that may occur after installation.

Set Contents

The following items are supplied with the GY470:

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

• Always check the transmitter and receiver battery voltage to ensure they have enough remaining capacity to complete the flight.
• The GY470 requires 3-5 seconds to initialize when the power is turned on. Do not move the helicopter and do not move the rudder stick during this initialization or the gyro may not initialize properly. Once the initializa-tion process has been completed the rudder servo will move (a little) sev-eral times indicating that the GY470 is now ready for flight.
• Always ensure that there is some slack in the gyro cables to help maximize performance. Always use the supplied gyro mounting pads to attach the gyro to the helicopter mechanics. Do not use a strap that en-compasses the GY470 sensor. This may affect the overall performance of the gyro.
• If you are switching between NORMAL mode and AVCS mode in flight, please keep in mind that you must have the gyro re-learn the center posi-tion after making a trim change within the transmitter. To memorize the new center position simply flip the gain switch on the transmitter three times between NORMAL mode and AVCS mode (NORMAL → AVCS → N ORMAL → AVCS → NORMAL → AVCS) within one second. The servo will center indicating that the new center position has been memorized.
• Be sure to use a digital servo. Use only digital servos with the GY470. Using the GY470 with an analog servo will damage the servo.
• 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.
• Do not drop the GY470 onto a hard surface or subject the GY470 to a strong shock as this may damage the sensor.
•  When using the GY470 in the AVCS mode, set revolution mixing to OFF.
• Do not place gyro near heating equipment (engine, motor, ESC, bat- tery, servo, etc.). Always allow the gyro to adjust to the surrounding envi-ronmental temperature before flight. A large temperature change during use will cause drift and other operational issues.

Connecting the GY470

Connecting the GY470 (S.BUS)

Mounting to Fuselage

GY470 installation precautions

• Always use the accessory sensor tape to install the GY470. Install the GY470 the center of the sensor tape.
• Depending on the vibration from the heli-copter, the sponge may tear near the cor-ners of the sensor tape. If the helicopter is flown in this state, vibrations will not be sufficiently absorbed and the sensor may fall off. Before flight, always check the sen-sor installation state. If the sponge is torn, replace it.

*Oil on the sensor bottom and the part in- stalled to the frame can be wiped off with cleaner, etc.

Rudder Servo Linkage Check

In the NORMAL mode, make the following linkage checks:

• Make the initial linkage connections in the NORMAL mode. In this case, make adjustments mechanically and make mini-mum trimmer adjustments at the transmitter.
• Move the rudder stick to the right and left and check the di-rection of operation of the tail rotor. If the tail rotor turns in the wrong direction, reverse the direction with the transmitter reverse function.
• In the rudder neutral position, connect the linkage at the position at which the servo horn and control wire are perpendicular.

Adjustments

Please take a look at both the directions for the helicopter as well as the transmitter.

Setup before a flight [ Remote gain use ]
Adjusting gain with the transmitter.
When S.BUS connection or the gyro gain CH of the port 2 of a gyro and a receiver is connected.

1. Set the servo selection switch to the setting for your tailrotor servo. See chart below.

2. Set up your transmitter by following the directions in the gyro setting menu manual. Gyro gain is set up to 50%by AVCS. Please refer to the graph, AVCS, NORMAL or when unclear. It judges by the LED on the GY470. AVCS: Red NORMAL: Green

3. Receiver ON → The GY470 requires 3-5 seconds to initialize when the power is turned on. Do not move the helicopter and do not move the rudder stick during this initialization or the gyro may not initialize properly. Once the initialization process has been completed the rudder servo will move (a little) several times indicating that the GY470 is now ready for flight. If the neutral has shifted, LED will blink orange. In that case, it reboots.

4. Move the rudder stick to the left and right and make adjustments with the limit trimmer. Adjust for maximum travel, making sure the servo horn doesn’t hit the linkage.
   【Adjustment at the limit trimmer】

5. If the rudder servo moves to the Right when the nose of thehelicopter moves to the Left, the gyro direction is correct. If the rudder servo moves to the Left, switch the direction using the Gyro Direction Switch. *This check is performed in the state where an engine (motor)never starting.

If you try to fly the helicopter while the gyro direction is incorrect, when the rotor rotates clockwise, the helicopter nose will yaw to the Left and cause an extremely dangerous situation.

[ Remote gain not use ] Adjusting gain with the GY470 trimmer.
When not using an S.BUS connection and port 2 is not connected. In this case, a limit trimmer is automatically changed by the gyro gain setting trimmer. A limit is fixed by 50 degrees of right and left.

1. Similarly the procedure of 1. 3. 5 is followed.
2. First, we suggest to start with AVCS set to 50%.
   ● A trimmer’s operation
   ＊Since the trimmer is small and delicate, operate it by gently using the provided mini screwdriver.
   

Operation in AVCS mode
If the rudder stick is operated or the helicopter is moved when the helicopter was stopped during operation in the AVCS mode, the servo will not return to the neutral position even if the rudder stick is re-turned to the neutral position, and when the rudder stick is moved, the rudder servo controls operation until the tail reaches the maximum point. This is caused by addition of an integration function as an AVCS mode operation and is not an abnormality. In actual flight, the gyro constantly monitors movement of the tail and controls the servo so that movement of the tail is stopped.
AVCS mode servo neutral position check method;
If the rudder stick or the helicopter was moved in the AVCS mode, the servo will not return to its original neutral position. When the power is turned on, the servo will return to the neutral position. The servo neutral position can also be checked by the following method.

• Neutral position
  Move the rudder stick 3 times to its full stroke to the left and check method right at an internal of within 1 second and immediately return the rudder stick to the neutral position. The servo moves to the neutral position about 1 second later.
  

Flight Adjustments

Adjust the transmitter and gyro while repeatedly taking off and landing and with the aircraft on the ground. Transmitter adjustments must not be made while flying because it is dangerous.

1. Set the sensitivity to the position at which hunting does not occur during hovering and flight.
2. Adjust the hovering and flight rudder effect using the transmitter’s D/R or AFR function.

• Do not adjust with the End Point (ATV) function. If the End Point (ATV)function is used, trimming may change.

 NORMAL Mode

NORMAL mode sends control signals to the rudder servo only when the tail of the helicopter moves. When the tail stops mov-ing, the control signal from the gyro becomes zero. Conversely, the AVCS mode continues to send control signals to the servo even when the tail of the helicopter stops moving. The following sequentially describes the NORMAL mode and the AVCS mode.

Operation of NORMAL mode
Basic operation is described by considering the case when the helicopter is hovering under cross-wind conditions. With a nor- mal mode, when the helicopter encounters a cross-wind, the force of the cross-wind causes the tail of the helicopter to drift When the tail drifts, the gyro generates a control signal that stops the drift. When the tail stops drifting, the control signal from the gyro becomes zero. If the cross-wind continues to cause the tail to drift in this state, the “stop” operation is repeated until the tail faces into the winds. This is called the “weathervane” effect.

Operation of AVCS mode
Conversely, with an AVCS mode, when the helicopter encoun-ters a cross-wind and the tail drifts, a control signal from the gyro stops the drift. At the same time, the gyro computes the drift an- gle and constantly outputs a control signal that resists the cross- wind. Therefore, drifting of the tail can be stopped even if the cross-wind continues to effect the helicopter. In other words, the gyro itself automatically corrects(auto trim) changes in helicopter tail trim by cross-wind. Considering operation of an AVCS mode, when the tail of the helicopter rotates, the servo also rotates in accordance with the angle of rotation of the tail. When the tail stops rotating, the servo judges that it has stopped in that position. This is the auto trim function.

What is S.BUS

Unlike conventional radio systems, the S.BUS system uses data communication to transmit control signals from a receiver to a servo, gyro, or other S.BUS compatible device. This data includes commands such as “move the channel 3 servo to 15 degrees, move the channel 5 servo to 30 degrees”to multiple devices. The S.BUS devices execute only those commands for their own set channel. For this reason, it can be used by connecting multiple servos to the same signal line.

• • Set the channel at the S.BUS servos by using an SBC-1 channel changer or a CIU-2 USB serial interface.
• • Can also be used together with conventional servos. However, conventional servos cannot be used by the S.BUS output.
• • When using servos with a remote battery pack, use S.BUS Hub with Cable (2-way/remote battery pack use).
• Please refer to the instruction manual of S.BUS Hub with Cable (2-way/remote battery pack use) for the connection method.
• Please turn on the power supply of the transmitter first without fail, and, next, turn on the receiver if you use S.BUS. Moreover, please use it after it confirms the operation without fail. Otherwise, the S.BUS communication cannot be judged and it is likely to malfunction.
• The wiring for the S. BUS servo is replaced at power supply OFF. If you replace the wiring in power supply ON, S. BUS communications cannot be judged, and it seems to malfunction.

FUTABA CORPORATION
Hobby Radio Control Business Center Sales & Marketing Department
1080 Yabutsuka, Chosei-mura, Chosei-gun, Chiba-ken, 299-4395, Japan TEL: +81-475-32-6051, FAX: +81-475-32-2915

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