S3103/S3107 Servo Horn Cross-Arm Upgrade FU1K12801 for Futaba 2pcs  [FU1K12801]

Overview of the horn and its role

This Futaba FU1K12801 servo horn cross-arm pack contains two machined aluminium arms intended as spare or replacement linkage components for the listed Futaba servo models. They mount to D5mm style servo outputs and provide a reliable anchor for steering and control linkages on RC vehicles.

Notes for use: the item does not include mounting screws or packing, so acquire correct fasteners separately, make sure the spline orientation is correct prior to tightening, and set the horn at neutral while configuring to avoid binding. As a mechanical part, setup focuses on eliminating slop and getting correct throw geometry rather than any electronic configuration.

Setup tips: fit and check one horn at a time to verify center position, fasten with suitable hardware for the D5mm interface, and carry out low-input movement tests to confirm smooth operation. For tuning endpoints and centering, adjust linkage lengths incrementally and re-test steering endpoints.

Model compatibility

• S3103
• S3107
• 3153
• 3156
• 3157