User manual FUTABA GY501

[. . . ] AVCS GYRO GY501 INSTRUCTION MANUAL YAW-AXIS STABILIZER FOR MODEL HELICOPTER (RATE GYRO) 1M23N04302 AVCS GYRO GY501 INSTRUCTION MANUAL YAW-AXIS STABILIZER FOR MODEL HELICOPTER (RATE GYRO) 4 Thank you for buying a GY501 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 Up to now, movement of the tail from side to side due to changes in the wind, flight posture, and other disturbances during model helicopter flights was minimized by increasing the sensitivity of the gyro. However, a bad effect is that the sensitivity may be increased too much so there was a limit on how much the tail could be controlled. [. . . ] The higher the gyro sensitivity, the smaller the amount of this drift. However, if the sensitivity is high, hunting will occur and, therefore, the sensitivity amp has a limit. · Drifting stop 25 Forward Side wind 26 BEFORE USE AVCS gyro This following describes how the AVCS system works when the helicopter is exposed to a side wind while hovering, the same as the preceding item. When the helicopter is exposed to a side wind, the tail begins to drift. The 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". The "return to original position" operation added to the AVCS system improves rudder trim operation. In other words, the gyro can automatically trim the rudder against side winds. When a helicopter is flying in the forward and reverse directions, the rudder trim is changed to advance, but with the AVCS system, this trim change is performed automatically and instantaneously so that the tail remains extremely stable even during high-speed reverse flight. The AVCS system requires a high-precision angular velocity sensor. The GY501 realizes a high-precision angular velocity detection function and extremely small output drift by using a new type of gyro sensor. This minimizes rudder neutral position drift during flight and eliminates the need to trim the rudder during flight. · The tail remains extremely stable. Forward Side wind BEFORE USE Differences in rudder control method The following describes the differences between conventional gyro and AVCS gyro rudder control. The conventional gyro sends the rudder control signals from the transmitter to the rudder servo and starts to move the tail. When the tail moves, the gyro detects this movement and generates a signal to stop it. If the tail continues to move even in this state, a rudder control signal larger than the signal from the gyro must be applied from the transmitter. That is, the difference between the rudder control signal from the transmitter and the control signal that attempts to stop this from the gyro becomes the actual amount of movement of the tail. Ordinarily, the rudder control signal is amplified 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. The original AVCS (Angular Vector Control System) came from this. In the AVCS mode, when the transmitter rudder stick is moved when the helicopter was stopped, the rudder servo controls operation until the tail reaches the specified rotational speed. [. . . ] The setting range is -20% to +20%. Servo Frame Rate Initial value: NOR Sets the servo output frame rate. The transmitter frame rate (Nor) or 1/2 the transmitter frame rate (High) can be set. Normally, use at "Nor". 42 DATA SETTING Operation Mode Setting Initial value: CMT Sets the gyro operation mode. In the "NOR" mode, both G1 and G2 operate in the Normal mode. [. . . ]