4mm EX Washer Hirobo HI2506040 - Thin Spacer for RC Helicopter  [HI2506040]

4mm EX shim for accurate rotorhead clearance

This EX washer, sized at 4mm, is a slim RC-scale spacer designed for precise spacing and alignment in helicopter assemblies. It helps remove unwanted play between mating parts, supports linkage pivot alignment, and sets minimal clearances around bearing seats in the rotorhead.

To fit, place the washer over a 4mm shaft or a 4mm bolt shank where a thin spacer is needed. Stack several washers to achieve the required thickness and confirm free rotational movement after fitting. Use appropriate small hand tools and do not force oversized components through the washer to avoid damage.

In setup work, the washer is ideal for small adjustments when replacing a full spacer is unnecessary; it lets you tweak linkage geometry and reduce endplay without swapping major parts.