Hirobo HI2521071 3 X 7 X 4S Collar - Rotor Head Spacer  [HI2521071]

Spacer for blade pitch calibration

This collar is supplied as an RC-scale replacement for Hirobo helicopter assemblies that need a compact collar to control axial position or spacing. Its 3 x 7 x 4S dimensions suit use as a small spacer or locator inside rotor head linkages and related small parts.

Installation is straightforward: place the collar on the correct shaft or pin and secure it with the model's existing fastening method. Always check axial alignment and play after fitting, and re-tighten the host fastener to the manufacturer's recommended torque to reduce the risk of loosening during operation.

In setup and tuning, the collar delivers consistent spacing and repeatable positioning; it is useful when adjusting blade pitch geometry, aligning blade grips, or when replacing worn locating parts during scheduled maintenance.