3 x 5 x 4.5F Shaft Collar for RC Helicopters - Hirobo HI2521095  [HI2521095]

Impact on Trim and Control from Collar 3 x 5 x 4.5F

This collar is an RC-scale accessory intended for helicopter general parts and assemblies. The part is identified as HI2521095 and the 3 x 5 x 4.5F notation indicates the sizing to verify against the shaft, pin, or bore where it will seat.

Used as a locating and retention element within rotor or transmission subassemblies, the collar maintains axial position of small shafts and linkages, which can influence trim and control responsiveness. For setup, match the 3 x 5 x 4.5F sizing to the mating component, orient the collar correctly, and ensure it seats securely to avoid shifting under load.

Check for wear, out-of-round condition, or looseness where the collar meets shafts or bearings and replace if it no longer provides firm retention. Clean mating areas to keep the fit consistent so tuning adjustments remain stable after maintenance.