Hirobo HI2500070 3x9x3 mm Open Bearing Pair for RC Helicopters  [HI2500070]

Compact bearings for rotor and linkage duties

This is an aftermarket RC-scale ball bearing set intended for general helicopter upkeep and small linkage pivots. Identified by the HI2500070 designation, the pack contains 2 open type bearings at 3 x 9 x 3 mm, suited to tight bearing housings and compact assemblies.

These bearings act as low-profile rotating supports within rotor assemblies, swash linkages, control arms and other small pivots. Check seating diameter and axial clearance on the hub or linkage before installing to avoid binding, and inspect the mating bore for wear or deformation.

When fitting, press the bearing squarely into the bore with a drift or bearing driver that bears on the outer race; do not transmit force through the inner race. Confirm free rotation after seating. Apply light rotary oil sparingly for open bearings if dust exposure is low, or plan regular cleaning and relubrication under harsher conditions.

The item is sold as an RC accessory component for model aircraft and related scale parts, not for full-scale vehicle use.