XRB SR Main Gear Replacement – Hirobo HI0301045  [HI0301045]

XRB SR Main Drive Gear

This main gear is the replacement rotor component specified for XRB SR helicopters by the original part code. It transfers 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 needed, check shaft seating and bearing condition, then fit the gear with correct axial position. Verify gear mesh and clearance by rotating the main shaft slowly by hand before applying power, and adjust shims or spacers if the mesh appears tight or uneven.

During setup the main gear primarily influences mesh consistency and drivetrain smoothness rather than direct flight handling. Proper mesh reduces noise and wear, and helps maintain predictable tail and rotor tracking. Include a visual check for wear, chips, or runout as part of pre-flight inspection.