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Which servos can be used with AR7200BX/AR7300BX/AR7210BX

A rule of thumb to find well suited servos for you flybarless helicopter: As strong as necessary, as fast as possible, with less dead band as available.

Servo torque in kg/cm should be at least 3-4 times the heli weight (in kilogram). Speed should be at least 0.1s/45°. The faster the better. In addition the servo should be very precise, have little gear backlash and a low dead band. And of course it should be a digital servo that supports high frame rates (200Hz or more). Also using special heli servos which are designed for maximum vibration resistance is a good choice.

Note that all the speed is useless if the torque is not enough. In doubt when two servos of a series are only slightly different in speed and torque, normally the more powerful is in advantage.

Anyhow, if in doubt ask the manufacturer of the servo if it can be used in combination with flybarless/gyro systems. Not all servos can handle the additional stress of getting different control signals every few milliseconds. Also it must be said that not all servos can be used at maximum frequency even if so it is told on the servo's data sheet. Depending on air temperature, voltage level and heli size it is possible that servos can not be driven at their limit as the servo motor or electronics may heat up too much.'