SX Series Helicopter Autorotation Torque Limiter HI0404543 by Hirobo  [HI0404543]

Rotor autorotation: product brief

The Hirobo HI0404543 autorotation torque limiter is an aftermarket replacement designed for RC helicopter rotor heads where it manages autorotation torque transfer. It is identified as a common spare for Eagle, Freya, EX and SX series machines, supporting safer autorotation practice and controlled descent testing.

The device cushions torque flow between the rotor assembly and drivetrain in free-spinning conditions to help smooth rotor deceleration during autorotation. It is intended to install using existing mounting points so original tracking and alignment remain unchanged.

Before fitting, confirm the limiter lines up with your helicopter's interface and that no additional parts are required. After installation, inspect rotor lateral play and run a conservative hover to ensure the autorotation response is as expected.

Choose this limiter to restore consistent autorotation behaviour while keeping factory fitment and alignment intact.