Hirobo HI2521145 Collar 2 x 3 x 6 for Helicopter Shaft Retention  [HI2521145]

Small spacer for shaft endplay control

This Hirobo collar is intended as a basic RC helicopter general part that provides axial retention and spacing in rotor and control link assemblies. The marking 2 x 3 x 6 describes the nominal size for placing the collar on shafts or within compact assemblies.

Apply the collar to prevent unwanted axial movement and to offer a repeatable seating surface for neighbouring parts. Prior to fitting, check shafts and receiving bores for imperfections and confirm the collar seats square to avoid eccentric forces that could affect balance.

Used correctly, collars like the HI2521145 help maintain consistent linkage geometry, which in turn reduces the need for ad hoc shimming during setup and testing.