Hirobo HI2521067 RC Helicopter Shaft Collar 4 x 5 x 6.5 mm  [HI2521067]

Shaft locator collar 4 x 5 x 6.5

This collar is an RC-scale shaft part identified by the 4 x 5 x 6.5 marking and offered as a general-purpose item for model helicopters. It is used as a spacer and axial locator where consistent spacing and repeatable blade positions contribute to rotor balance and control geometry.

Installation is straightforward: position the collar on the shaft to the required point and secure it in line with your hub and shaft design. The nominal size is intended to match small rotor interfaces; always verify the actual fit before final assembly to avoid contact with bearings or nearby hardware.

In tuning and servicing, the collar is a simple tool for adjusting blade tracking and keeping head geometry consistent after component changes. Keep spare collars available for rebuilds and setup variations where millimetre adjustments alter rotor behaviour.