HIROBO HI2521074 13 x 16 x 12 Collar — Shaft Location Part for RC Helicopters  [HI2521074]

Shaft location control for small helicopter drivetrains

Shown in the Hirobo helicopter general parts range, this HIROBO HI2521074 collar carries the 13 x 16 x 12 marking and is made for RC-scale shaft applications. Its purpose is to provide a compact axial stop or spacer on driven shafts where holding shaft position affects rotor tracking and the alignment of drivetrain elements.

Successful use requires checking the collar's bore and external proportions against the shaft and the surrounding components. In practice, measure the shaft diameter and available frame or rotor head clearance to ensure the 13 x 16 x 12 sizing will fit without binding. The part is recommended for hobbyist maintenance, repair and tuning rather than replacing entire subsystems.

Fitted correctly, the collar serves as a positional control item: it can limit unwanted axial motion, assist in keeping stable gear mesh, and provide a repeatable reference point during setup and trim adjustments.