Hirobo HI0301045 XRB SR main gear - RC helicopter rotor replacement  [HI0301045]

Main gear for XRB SR helicopters

This main gear is the replacement rotor component identified for XRB SR helicopters by the original part code. It serves the primary function of transferring motor torque to the rotor head on RC-scale helicopters and is intended as a service or spare part for routine maintenance and repairs.

Installation is straightforward for experienced model technicians: remove the canopy and rotor head as required, verify shaft seating and bearing health, then fit the gear ensuring correct axial position. Check gear mesh and clearance by rotating the main shaft slowly by hand before powering up, and adjust shims or spacers if mesh looks tight or uneven.

In tuning and setup, the main gear affects mesh consistency and drivetrain smoothness more than flight characteristics directly. Proper mesh reduces noise and wear, and helps keep tail and rotor tracking predictable. Regular inspection for wear, chips, or runout is recommended as part of pre-flight checks.