Futaba FU1K27101 Serration Servo Horn Type-U Six-Arm 3pcs for S9152/S9153 (W/O Screw)  [FU1K27101]

Futaba Type-U Six-Arm Serration Servo Horn

This is an RC-scale serration servo horn designed for Futaba S9152 and S9153 servos, supplied as a set of 3 pcs without mounting screws. The Type-U six-arm layout gives multiple lever positions for tuning mechanical advantage and steering throw while the serration interface locates to the servo spline to reduce slip under load.

Installation is straightforward for standard spline servos: seat the horn fully onto the servo spline with the serrations engaged, choose the arm that delivers the desired travel and leverage, then secure the horn to the servo output with a suitable screw supplied by the builder or from the servo kit. Verify spline alignment and check for free movement across the full steering arc before final tightening.

In tuning use the six available arm positions to adjust steering response without changing servo endpoints. A shorter arm reduces throw and increases torque at the linkage, a longer arm increases throw and reduces torque. This horn is intended as a direct mechanical interface for tuning steering geometry and linkage behavior on RC cars and similar models.