Hirobo HI2521062 5 x 6 x 9.5 Shaft Spacer Collar  [HI2521062]

Compact collar for shaft spacing and tuning

The Hirobo HI2521062 collar is intended to locate and secure small parts on thin shafts used in model helicopters, helping preserve the axial position needed for setup and tuning. Its compact form and defined internal bore support accurate placement.

When installing the collar, verify the shaft diameter against the 5 x 6 x 9.5 marking to ensure fit. Position the collar at the required axial point, confirm that nearby components line up, and lock it in place using the collar's fastening method. After fitting, run a slow rotation check and visually inspect concentricity and clearance prior to flight.

During tuning the collar can act as a spacer or stop; replacing damaged collars restores predictable spacing without changing other drivetrain settings.