Hirobo HI2521145 2 x 3 x 6 Collar for Helicopter General Parts  [HI2521145]

Compact collar for rotor and linkage fittings

This Hirobo collar is an RC helicopter general part intended as a simple retention and spacing element within rotor and control link assemblies. Its 2 x 3 x 6 marking denotes the nominal collar size used to locate components on shafts or inside small housings.

Fit this collar where accurate axial positioning is required to limit endplay or to provide a stable bearing surface for adjacent parts. Check mating shafts and bores for burrs or damage before fitting, and ensure the collar sits squarely to avoid eccentric loading that could upset rotor balance.

In setup and trim work, collars like the HI2521145 provide consistent geometry for linkages and pitch components, reducing repeated shimming and helping maintain predictable control response during test flights.