Hirobo HI2521122 Collar 5 x 6.5 x 12.5 shaft collar for RC helicopter assemblies  [HI2521122]

Shaft collar for RC helicopters

This Hirobo collar (HI2521122) is an RC-scale shaft collar intended for use in helicopter general parts and assemblies. The marked dimensions 5 x 6.5 x 12.5 should be checked against your model's shaft and component stack before use.

Functionally, the collar serves as an axial locator and spacer in rotor linkages, swashplate stacks, and other shafted subassemblies where controlled end-play is required. It is neutral in design and intended to integrate with existing mounting hardware in the airframe rather than replace model-specific retainers.

Installation guidance: verify the collar's fit on your shaft and confirm alignment with adjacent parts, slide into position, and secure using the retaining method already provided by your helicopter (set screws, retaining clips or existing collars on the model). After installation, check for rotational freedom and minimal axial play before flight.

For tuning and setup, use the collar to fine-tune servo-to-rotor geometry and to lock axial positions once the control linkages and rotorheads are trimmed. Always test changes on the bench at low throttle and confirm no interference with blades, swashplate, or control linkages.

This is an RC-scale accessory for helicopter models, not intended for full-size or non-hobby applications.