Hirobo Helicopter Shaft Collar HI2521108 3 x 4 x 5.1 mm  [HI2521108]

Compact collar for shaft alignment

This Hirobo HI2521108 collar is an accessory made for use with Hirobo helicopter general parts in small-scale RC models. It functions as a shaft collar to lock components in axial position on model shafts, helping maintain alignment between rotating elements and surrounding assemblies.

Fitting is uncomplicated: locate the collar at the required shaft point and secure it to prevent axial movement. It is often employed where a small, repeatable stop is needed between bearings, gears or hubs; always check compatibility before altering assemblies.

During rotorhead or tail tuning, collars of this kind are handy for locking tiny adjustments and holding trim between flights. Periodic inspection for wear and ensuring secure fastening will improve reliability in flight.