Hirobo HI2521081 4x5x6.5S Collar - Shaft Lock for RC Helicopters  [HI2521081]

Use and function of the shaft collar

This Hirobo HI2521081 collar functions as a radial locking component to maintain axial position on RC helicopter shafts. The part identifier states the nominal size so modellers can confirm fit against their shaft before use. Its mechanical purpose is to prevent axial displacement of gears, bearings or rotor items during bench adjustments and general maintenance.

Fitting is uncomplicated: confirm the collar sizing, position it where required, and secure using the model's suggested method or appropriate hardware. For dependable results, clean mating surfaces and verify endplay after tightening. The collar is useful for holding alignment while adjusting blade pitch or spindle location.

Never improvise torque settings; follow the guidance from your airframe or component manufacturer to avoid harming shafts or surrounding parts. This item is supplied as an RC-scale helicopter spare part only.