Hirobo HI2521027 Ball Bearing Collar for 3x6x2.5 Bearings  [HI2521027]

Bearing positioning collar for small RC rotors

This Hirobo collar locates and retains 3x6x2.5 mm ball bearings inside small rotating subassemblies and linkages on RC helicopters. It serves as a mechanical spacer that controls axial clearance where bearings meet shafts or housings, which is particularly useful during repairs and routine servicing of rotor heads and link pivots.

To install, verify the bearing is 3x6x2.5 mm, seat the collar so it bears on the race or housing face, then check that rotation is free and axial clearance is correct before flight. For reliable fitment always measure bearing inner/outer diameters and the mating shaft or bore.

As a repair item the collar helps maintain consistent bearing position to reduce endplay and improve the repeatability of link movements following maintenance operations.