Hirobo HI2521077 Shaft Collar 5 x 9 x 9 compatible with Hirobo helicopter parts  [HI2521077]

Small-diameter shaft collar for helicopter linkages

This Hirobo collar is an RC-scale shaft collar intended for use in helicopter general parts where a compact mechanical stop or alignment sleeve is required. The product name includes the nominal dimension 5 x 9 x 9 which is the primary reference for checking fit against shafts and mating components.

Functionally the collar secures axles or small-diameter shafts, holds linkage positions, and provides a repeatable reference point during setup. It works as a mechanical locator during routine maintenance and fine tuning, helping preserve rotor geometry and linkage alignment without altering other components.

Installation is straightforward: position the collar on the shaft to the desired location, ensure alignment with adjacent parts, and secure the fixing method provided on the collar. After initial installation, re-check alignment under free rotation and during static checks to confirm the collar maintains the intended position during operation and tuning.

In tuning scenarios the collar is used to lock a setting once the correct geometry or clearance is found, allowing precise repetition of adjustments. Regular inspection for wear or movement is recommended as part of periodic maintenance to retain reliable control link positions.