AVCS GYRO GY502 INSTRUCTION MANUAL YAW-AXIS STABILIZER FOR MODEL HELICOPTER (RATE GYRO)
Thank you for buying a GY502 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. FOREWORD The GY502 is an AVCS (Angular Vector Control System) rate gyro developed for use with .60 type and other model helicopters. [Features] •High-speed arithmetic processing by microcomputer allows high-speed pulse drive of servos.
TABLE OF CONTENTS FOR SAFETY •Meaning of Special Markings ---------------------------- 4 •Mounting/Operating Precautions ------------------------ 5 •Fuselage Maintenance Precautions ---------------------- 7 BEFORE USE •Set Contents ------------------------------------------------- 8 •AVCS Gyro ------------------------------------------------- 9 •Digital Servo Compatibility ----------------------------- 11 DATA SETTING •Name and Function of Each Part ------------------------ 12 •LCD Display and Edit Keys
FOR SAFETY FOR SAFETY To ensure safe use, observe the following precautions. Meaning of 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.
FOR SAFETY Mounting/Operating Precautions Insert the connectors fully and firmly. If a connector works loose due to vibration during flight, control may be lost and result in a dangerous situation. Always use the accessory sensor tape to install the sensor to the fuselage. This is necessary to securely fasten the sensor to the fuselage so that operation of the gyro does not transmit unwanted fuselage vibrations directly to the sensor.
FOR SAFETY Precautions When Turning on the Power Switch During initialization, the message “-Hello-” appears on the GY502 LCD screen. Do not move the helicopter until this message disappears (in about 3 seconds). Also, do not move the transmitter rudder stick from the neutral position during this period. Always check the direction of operation of the servos.
FOR SAFETY Check the remaining receiver/gyro/servo nicd battery operating time during the adjustment stage and decide how many flights are remaining. Never use the transmitter rudder trim in the AVCS mode. When the rudder is trimmed during flight, the neutral position will change. When using the GY502 in the AVCS mode, set revolution mixing to OFF. Fuselage Maintenance Precautions Use a tale rotor drive tube or other part with a high torsion performance for the tail drive.
BEFORE USE BEFORE USE Set Contents After unpacking the GY502 set, first check if the following parts are provided: GY502 control amp (x1) GY502 sensor (x1) Sensor tape (x3) Mini screwdriver (x1)
BEFORE USE AVCS Gyro Differences Between AVCS Gyro and Conventional Gyro Compared to a convention gyro, the AVCS gyro has a substantially improved tail control capacity. Gyro operation also differs from that of conventional systems in a number of ways. The following sequentially describes the conventional gyro and the AVCS gyro. Conventional gyro The conventional gyro detects movement of the helicopter's tail and controls the rudder servo so that movement of the tail stops.
BEFORE USE gyro controls the servo so that the movement of the tail stops, the same as a conventional gyro. At the same time, a sensor is controlled so that the tail is rotated in the opposite direction (returns to the original position). In short, the conventional gyro performs an operation known as "drifting stop", but the AVCS system performs an operation that "stops drifting and returns to original position".
BEFORE USE several times over by the gyro amp and is balanced with the gyro control signal so that the transmitter can be used at the normal steering angle. The AVCS system uses a different rudder control method. As described in the preceding section, it has additional functions that "attempt to return movement by external force to the original position" and that generate an angular velocity proportional to the rudder control signal. That is, it functionally controls the speed of rotation of the tail.
DATA SETTING DATA SETTING Name and Function of Each Part GY502 control amp LCD display Displays the set data. (8 characters X 1 line) (Input/outputterminals) Gyro sensor input Rudderservooutput (Receiverconnectors) Edit keys Used when setting data. Operated by pushing with the accessory mini screwdriver. Remote gain input Rudderinput LCDcontrasttrimmer Allows adjustment of the contrast so that the LCD display is easiest to see. It is adjusted with the accessory mini screwdriver.
DATA SETTING LCD Display and Edit Keys LCD display Set data display and operation status monitoring are possible. Edit keys Setup screen call The setup screens can be sequentially called with the FUNC+ or FUNC- key. For the order in which the setup screens are called, see the function map. Data setting Perform data setting with the DATA+ or DATA- key. When setting a value, the data is increased when the DATA+ key is pressed and is decreased when the DATA- key is pressed.
DATA SETTING Function Map Power ON FUNC ”-” key Normal screen display (P15) FUNC ”+” key Gyro Reverse (P16) Gyro Gain Adjustment (P16) Rudder Control Gain (P17) Control Delay I (P17) Control Delay D (P17) Gain Tracking (P18) Operation Mode Setting (P18) Servo Frame Rate (P19) AVCS sense (P20) Linkage Limit Setting (P20) Power on screen display (P15)
DATA SETTING GY502 Functions Setting Power on screen display When the gyro power is turned on after the transmitter power was turned on, -Hello- blinks for about three seconds to initialize the data inside the gyro. During this period, do not move the transmitter rudder stick or the helicopter. If the transmitter rudder stick or the helicopter is moved by mistake, the rudder neutral data will not be correctlyread.
DATA SETTING Gyro Reverse Initial value: NOR Sets the gyro operation direction. NOR or REV can be selected. Set so that when the helicopter is banked right, left correction rudder is applied and when the helicopter is banked left, right correction rudder is applied. Gyro Gain Adjustment Initial value: 100% Adjusts the gyro gain. Setting range is 0 to 120%. Two-point (G:1, G:2) gain adjustment is possible.
DATA SETTING Rudder Control Gain Initial value : ACG: 100%, NCG: 120% Adjusts the rudder stick operation gain. Setting range is 10% to 250%. AVCS and NOR mode gain can be set independently. In the AVCS mode, ACG is displayed and in the NOR mode, NCG is displayed. The display automatically changes to A or B according to the direction of the rudder stick and the gain of each direction can be set. This function is used when tracking rudder operation gain between the AVCS and NOR modes.
DATA SETTING Gain Tracking Initial value : +0% Adjusts left and right tail braking tracking. Setting range is -20% to +20%. For example, when there is a sense of hunting when stopping left pirouette or the helicopter drifts when stopping right pirouette, shift Trk in the + direction. In the opposite case, shift Trk in the - direction. Operation Mode Setting Initial : CMT Sets the gyro operation mode. Settings are NOR, AVC, and CMT. In the NOR mode, both G1 and G2 operate in the AVCS mode.
DATA SETTING Servo Frame Rate Initial value : Low Switches the servo output pulses. The Low mode outputs pulses for an ordinary servo. Switch to the High mode only when using a digital servo. When using a servo that cannot be driven by high-speed pulses, other than a digital servo, never set servo frame rate to the High mode. The servo may be destroyed.
DATA SETTING AVCS Sense Initial value : 100% Adjusts the rudder control characteristic in the AVCS mode. Setting range is 50 to 150%. Adjust by checking the rudder operation feel and stopping characteristic. Linkage Limit Setting Initial value : 100% Sets the rudder servo travel limit. Operate the rudder stick and adjust the rudder servo travel limit by pressing the +/- key so that the servo moves to the maximum linkage position. Use the same procedure to set both the left and right limits .
DATA SETTING Remote Gain Function The remote gain function lets operator perform AVCS mode and Normal mode sensitivity adjustment and operation mode switching from the transmitter. The channel used here is called the "remote gain channel". (Channel 5 is used.
DATA SETTING When Using a T9Z World Champion Model Transmitter Gyro Sense Mixing The Gyro Sense Mixing (GYR) function lets operator perform two-point gain adjustment at each condition. Set the sensitivity at all conditions. [GY502 Settings] Select the gyro operation mode at the GY502 Mode screen. (AVC, NOR, or CMT) [Transmitter Settings] ATV function: Adjust both the RATE A and RATE B rates to 100% at the transmitter ATV function setup screen. Gyro Sense Mixing function: 1.
DATA SETTING (Setting Example) Adjust the gyro gain at the Gyro Sense Mixing setup screen at each condition. The following shows a setting example in the CMT mode. Select the Dual Mode (DUO). GYRO SENCE DUAL 01 . MODEL-01. NORML HEL PCM 0: 23: 17 : MODE 85 % : GAIN 1 15 % : GAIN 2 0 20 40 60 80 100 END Sensitivity rate Choose the GAIN1 or GAIN2 by the CH5 switch.
DATA SETTING When Using a T9Z Transmitter Programmable Mixing The Programmable Mixing (PMIX) function lets operator perform a gain adjustment at each condition. Set the sensitivity at all conditions. [GY502 Settings] Select the gyro operation mode at the GY502 Mode screen. (AVC, NOR, or CMT) [Transmitter Settings] Function Control: Set the CH5 (GYR) switch to “NUL” at the transmitter Function Control (FNC) setup screen.
DATA SETTING (Setting Example) Adjust the gyro gain at the Programmable Mixing setup screen at each condition. The following shows a setting example in the CMT mode. Select the “ACTIVE”. PROG MIX 1 01 . MODEL-01. NORML HEL ACTIVE : MODE ( ON) *** GYR OFS PROG MIX 1 + 70 % TRIM: 0: 23: 17 ****** MSTR MIX MODE: ****** : MASTER SWT : SLAVE NXT : MIX TYPE LIN OFS HOV Select the “GYR”. PCM CRV CTL END Select the “OFS”. 01 . MODEL-01.
DATA SETTING When Using a T8Usuper Transmitter The Gyro Mixing (GYRO) function lets operator perform a gain adjustment at each Idle-Up switch position. [GY502 Settings] Select the gyro operation mode at the GY502 Mode screen. (AVC, NOR, or CMT) [Transmitter Settings] Gyro Mixing function: 1. Select the “ON” mode at the transmitter Gyro Mixing (GYRO) setup screen. 2. Select the Idle-Up switch(SW-E) for the sensitivity selection. 3. Set the “NORM”, “IDL1” and “IDL2” gains.
DATA SETTING (Setting Example) Adjust the gyro gain at each the Idle-Up swtch position at the Gyro Mixing setup screen. The following shows a setting example in the CMT mode. Select the “ON” mode. Select the Idle-Up switch(SW-E). Switch position Sensitivity rate Set the “NORM”, “IDL1” and “IDL2” gains at each setup screen.
DATA SETTING When Using a Transmitter ATV Function The ATV function lets operator perform a gain adjustment at each CH5 switch position. [GY502 Settings] Select the gyro operation mode at the GY502 Mode screen. (AVC, NOR, or CMT) [Transmitter Settings] ATV function: Set the ATV rates at the transmitter CH5 ATV function. [Sensitivity Display] The gain display indicates the actual gain at the GY502 normal screen display.
DATA SETTING When Using a GY502 Gyro Gain Adjustment Function [Transmitter Settings] Adjust both the ATV rates to 90% at the transmitter Ch5 ATV function. [GY502 Settings] Operation Mode Setting function: Select the gyro operation mode at the GY502 Mode screen. (AVC, NOR, or CMT) Gyro Gain Adjustment function: Set the G:1 and G:2 gains at the GY502 G:x screen.
DATA SETTING Initialization AVCS mode operation is based on the rudder neutral data stored in the GY502. When using the GY502 for the first time, or when the internal reference data and the transmitter neutral position differed when the transmitter neutral trim was adjusted, etc., the rudder neutral data must be read again. [At power ON] When the power switch is turned on, the GY502 automatically obtains the reference signal for AVCS function correction and initializes itself.
DATA SETTING Re-reading method In this case, quickly switch (interval of within 1 second) the transmitter remote gain switch between the Normal and AVCS sides at least three times and switch the AVCS side at the neutral trim position set in the Normal mode. This memorizes the new rudder neutral position in the GY502. When the transmitter has a function that allows trim setting for each flight condition, such as the T9Z, the AVCS mode trim position is fixed and this operation is unnecessary.
INSTALLATION AND ADJUSTMENT INSTALLATION AND ADJUSTMENT Install and adjust the GY502 as described below. •When making GY502 adjustments, always use the accessory miniature screwdriver and do not apply excessive force. Installing to Fuselage 1 Installing sensor and amp GY502 sensor Frame gyro bed •Install the sensor so that the bottom of the gyro is perpendicular to the main rotor shaft axial direction. Offset of this axis will also react in the roll and pitch directions.
INSTALLATION AND ADJUSTMENT 2 Connections Insert the connectors fully and firmly. If a connector works loose due to vibration during flight, control may be lost and result in a dangerous situation. Connect the GY502, receiver and servo as shown below. •Connect the sensor to the amp sensor input ("GYRO"). •Connect the amp rudder input ("RX,1-4") input connector to the receiver rudder channel (ch4). 3 Servo selection •Connect the rudder servo to the amp servo output ("SX").
INSTALLATION AND ADJUSTMENT *However, when using the gyro in the CMT mode, since the AVCS and NOR mode gain must be set during hovering and in flight, a transmitter with a gyro mixing function (T9Zwc series, T8Usuper series) is necessary. •For a description of transmitter setting, see the remote gain function (p21). 5 Rudder servo linkage check Make the initial linkage connections in the NOR mode. In this case, make adjustments mechanically and make minimum trimmer adjustments at the transmitter.
INSTALLATION AND ADJUSTMENT 7 Limit setting Move the rudder stick to the left and right and perform adjustment at the Lmt screen so that the servo operation angle becomes the maximum value at which the servo horn does not strike the linkage. *When flying, the servo horn does not move beyond this set angle, thus protecting the linkage. However, if the limit setting is too low, gyro performance will be effected. *In this mode, only the stick operates; the gyro does not operate.
INSTALLATION AND ADJUSTMENT When using a transmitter without a gyro gain switching function, connect the gain setting connector to an idle channel and set the GY502 G1 and G2 gains using this gain setting screen. Gain can be trimmed by means of the transmitter ATV function. 9 Transmitter setting check Checks the transmitter setting in the ACVS mode. Check that the transmitter is not set so that the neutral position has shifted. (Transmitter setting) •Set all rudder mixings to INH.
INSTALLATION AND ADJUSTMENT Flight Adjustments 1 In the AVCS mode, turn on the transmitter power, then turn on the gyro and receiver power. This reads the rudder neutral signal at the GY502. •Never move the helicopter or rudder stick during the approximately three seconds that the -Hello- display blinks. 2 Hover in the Normal mode and adjust the rudder neutral position. •In the AVCS mode, the rudder neutral position is automatically set, and linkage changes cannot be verified.
INSTALLATION AND ADJUSTMENT 5 Adjust the hovering and flight rudder effect using the transmitter's D/R or AFR function. •Do not adjust with the ATV function. If the ATV function is used, trimming may change. (If necessary) 6 When you sense a difference in the rudder effect between the AVCS and Normal modes, adjust using the GY502 rudder control gain.
INSTALLATION AND ADJUSTMENT 9 When you want to use rudder mixing in the Normal mode, set the transmitter so that rudder mixing is applied only during Normal mode operation. Never use rudder mixing in the AVCS mode.
REFERENCE REFERENCE Specifications * Specifications are subject to change without prior notice. GY502 Ratings Yaw-axis stabilizer for helicopter (rate gyro) Display device: 8-character dot matrix liquid crystal display Operating voltage range: DC 3.8V to 6.0V Current drain: 70mA (@5.0V, including sensor) Operating temperature range: -10 to +50 degree C Operating humidity range: 10 to 90%RH (no condensation) Dimensions: 57 x 32 x 15mm (amp), 34 x 34 x 16.
REFERENCE Definition of Abbreviations The following defines the abbreviations and symbols used in this manual in alphabetical order. The function names are given on the descriptionpages. A ACGA/B Rudder control gain (AVCS) p17 AFR AFR function. ATV ATV function. Steering angle adjustment function. AVC AVCS mode. AVCS AVCS system. AVCS mode. AVS AVCS sense. p20 C CMT Normal/AVC switching mode. D D1DA D1IA D/R DUO Control delay. p17 Control delay. p17 Dual rate function. T9Z dual gain control mode.
REFERENCE GY502 Parameters Sheet * Copy and use.
REFERENCE FUTABA CORPORATION Makuhari Techno Garden Bldg.
