Hirobo HI2521095 Collar 3 x 5 x 4.5F - Helicopter General Part  [HI2521095]

Helicopter collar 3×5×4.5F

This collar is an RC-scale accessory intended for use in helicopter general parts and assemblies. The item is identified by the model number HI2521095 and carries the dimension notation 3 x 5 x 4.5F in the product name, which should be used to verify fit against the shaft, pin, or bore where it will seat.

In practical terms the collar functions as a locating and retention element within rotor or transmission subassemblies on radio-controlled helicopters. For installation, match the 3 x 5 x 4.5F sizing to the mating part, ensure correct orientation, and confirm secure seating to avoid movement under load. During setup and tuning, collars like this help maintain axial position of small shafts and linkages, which supports predictable trim and control response.

When inspecting for service, look for wear, out-of-round condition, or looseness where the collar interfaces with shafts or bearings; replace the collar if it no longer provides firm retention. Keep the mating surfaces clean and free of debris to preserve fit and repeatability during routine maintenance.