HIROBO HI2521074 Collar 13 x 16 x 12 — Shaft Stop for RC Helicopter Parts  [HI2521074]

Role of the collar in rotor alignment

This part is catalogued among Hirobo helicopter general parts as model HI2521074 with a 13 x 16 x 12 designation. It functions as a compact shaft collar that provides an axial stop or spacer on driven shafts where correct shaft placement matters for rotor tracking and drivetrain geometry.

Practical fit depends on the collar's bore and external measurements matching your shaft and the layout of nearby components. Before fitting, confirm that the 13 x 16 x 12 dimensions correspond to your shaft diameter and the clearance offered by the frame or rotor head. The collar is designed for hobby maintenance, repair and tuning operations rather than replacing complete systems.

When used in builds or servicing, the collar acts as a positional control aid: it can reduce axial play, support consistent gear mesh, and serve as a reference during iterative setup and trim adjustments.