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

EX 4mm washer: rotorhead spacing guide

The 4mm EX washer is a thin RC-scale spacer intended for precise spacing and alignment inside helicopter assemblies. It removes looseness between mating parts, assists in aligning linkage pivots, and helps establish minimal clearances at bearing seats within the rotorhead.

To use, place the washer onto a 4mm shaft or a 4mm bolt shank where a thin spacer is necessary. Multiple washers can be stacked for added thickness; always check for free rotation after fitting. Employ small hand tools and do not force oversized components through the washer to avoid damage to the washer or nearby bearings.

For tuning and setup, the washer is ideal for small incremental changes when a full spacer replacement is not required, enabling precise adjustment of linkage geometry and reduction of endplay.