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

Precision 4mm EX washer for rotorhead alignment

This 4mm EX washer is an RC-scale thin spacer built for accurate spacing and alignment within helicopter assemblies. It eliminates play between mating parts, helps align linkage pivots, and establishes small clearances around bearing seats in the rotorhead area.

Installation is simple: slide the washer over a 4mm shaft or a 4mm bolt shank where a thin spacer is required, stack multiple pieces for incremental thickness, and confirm free rotation after fitting. Use small hand tools and avoid forcing oversized parts through the washer to prevent damage to the part and adjacent bearings.

For setup and tuning, this washer is suited to micro-adjustments when a larger spacer would be excessive; it allows fine-tuning of linkage geometry and reduction of endplay without replacing major components.