Hirobo HI2521105 3 x 4-6 x 17 Shaft Collar for RC Helicopter Trim and Repair  [HI2521105]

Miniature shaft collar for hobby helicopters

The Hirobo HI2521105 collar, sized 3 x 4-6 x 17, is a small service item used in RC helicopter upkeep. It secures axial location on rotating shafts to keep geometry stable while you adjust or fine-tune the rotor system.

Made to suit common Hirobo maintenance tasks, the collar reduces minor axial play and gives a replaceable option when locating parts have worn. It is supplied as a component for hobby rotorcraft maintenance rather than a complete assembly.

Fitting tips: slide the collar to the chosen shaft position and clamp with care to avoid over-tightening; check running clearance and inspect rotor alignment at low speed before returning to full operation. Use the collar to lock trim settings during setup and re-check stability with successive test flights.