Hirobo HI0301045 XRB SR Rotorhead Main Gear Replacement  [HI0301045]

Service main gear for XRB SR

The HI0301045 main gear is the replacement rotor component designated for XRB SR helicopters. It carries motor torque to the rotor head on RC-scale helicopters and functions as a spare for maintenance and repair work.

Fitment is straightforward for experienced technicians: remove the canopy and rotor head where required, inspect shaft seating and bearings, then slide the gear into position ensuring correct axial alignment. Manually rotate the main shaft to verify gear mesh and clearance before powering the model; adjust with shims or spacers where necessary.

When tuning, the main gear has the greatest effect on mesh stability and drivetrain smoothness rather than direct flight behavior. Correct mesh lowers noise and reduces wear, helping to maintain consistent rotor and tail performance. Include wear checks for chipped teeth and runout in your pre-flight routine.