SX Series Auto-Rotation Torque Limiter - HI0404543 by Hirobo  [HI0404543]

Autorotation limiter: product overview

This Hirobo HI0404543 auto-rotation torque limiter is an RC-scale replacement part for helmet-style rotor heads where the limiter regulates autorotation torque transfer. It is listed as a common component for Eagle, Freya, EX and SX series helicopters, and is intended for pilots tuning autorotation response or restoring factory behaviour after wear.

In operation the limiter reduces the torque passed between the rotor head and drivetrain when the blades are free-spinning, helping to steady rotor deceleration during autorotation. The unit is intended for direct substitution using the same mounting points and original fasteners so tracking and alignment are preserved.

When installing, make sure the limiter mates cleanly with your helicopter's existing interface and that no extra machining is required. After fitting, check rotor free-play and perform a cautious ground hover to confirm predictable autorotation characteristics before full flight testing.

This torque limiter offers a straightforward replacement path for pilots focused on consistent autorotation feel and rotor slowdown control, and it keeps factory mounting and alignment intact.