Hirobo HI2521122 5 x 6.5 x 12.5 Shaft Collar for RC Helicopter Assemblies  [HI2521122]

Precision shaft collar for heli models

This Hirobo collar (HI2521122) is an RC-scale shaft collar designed for general helicopter parts and subassemblies. The marked dimensions 5 x 6.5 x 12.5 should be verified against your model's shaft and component stack before fitting.

In use, the collar acts as an axial locator and spacer in rotor linkages, swashplate stacks and other shafted subassemblies where controlled end-play is required. Its neutral form is intended to work with existing mounting hardware rather than replace model-specific retainers.

Installation guidance: check the collar fit on your shaft, align with adjacent components, slide into place, and secure using the retaining method already fitted to your helicopter (set screws, retaining clips or existing collars). After fitting, confirm smooth rotation and minimal axial play before flight.

For setup and tuning, employ the collar to refine servo-to-rotor geometry and to lock axial positions once links and rotorheads are trimmed. Always bench test at low throttle and confirm there is no interference with blades, swashplate or control linkages.

This is an RC-scale accessory for helicopter models and is not intended for full-size or industrial applications.