Hirobo HI0404137 EX wash-out guide pin for EX series helicopter rotor head  [HI0404137]

Wash-Out Guide Pin for EX

This guide pin is an RC-scale wash-out alignment component named in the original Hirobo catalog as HI0404137, intended to interface with the EX rotor head geometry. Its role is purely mechanical: to provide a repeatable locator for wash-out setting and to help maintain blade tracking during head assembly and setup.

Installation is straightforward when replacing or checking wash-out geometry: locate the guide pin seating point in the rotor head, fit the pin without forcing, and confirm the wash-out arms move freely through their range without binding. Use appropriate hand tools and moderate torque on any retaining fasteners to avoid deforming the pin or surrounding alloy parts.

In tuning workflow the guide pin functions as a reference point rather than an active tuning element. During blade tracking and wash-out adjustments it helps ensure repeatable positions between assemblies, which is useful when swapping blades, servicing the head, or validating setup after repairs. Inspect the pin for straightness and surface wear during routine checks and keep spare pcs on hand to reduce bench time.