Hirobo HI0412329 4mm Blade Spacer for SDX, SCEADU and SZ-5 Rotor Heads  [HI0412329]

Blade Spacing Insert - 4mm

This replacement spacer is built to fit between the rotor blade and hub elements, maintaining a precise 4mm gap where the SDX, SCEADU and SZ-5 designs call for it. Its purpose is purely mechanical: to give consistent separation that supports accurate blade pitch and balance adjustments.

Fitting is simple for anyone experienced with rotor maintenance: remove the blade retention components, position the spacer on the blade root or shaft according to your rotor layout, then reassemble and tighten to the recommended settings. Keeping mating surfaces clean helps ensure correct seating and reduces the risk of runout.

In tuning sessions, this spacer preserves blade geometry so both blades respond similarly, which aids predictable cyclic behavior and lowers asymmetric vibration. After installation, recheck blade tracking and rotor balance and fine-tune pitch using blade grips or swash adjustments as required.