3 x 7 x 17.5mm Hirobo HI2521114 Helicopter Shaft Collar  [HI2521114]

The Hirobo collar is supplied as a direct replacement item for helicopter general parts applications. The 3 x 7 x 17.5 designation describes the nominal dimensional form used where controlled axial placement of shafts or linkage components is required. This component acts as a spacer and retention element rather than a powered part.

Fitting steps are simple: position the collar at the required axial location on the shaft, verify its seating against bearings or hubs, and use the model's existing retention hardware to secure it. Ensure surfaces are free of debris and that the collar does not interfere with adjacent moving assemblies prior to flight.

Adjustment role: collars like this are useful for fine adjustments to blade tracking, tail pitch links, or gearbox mesh. Make measured changes and inspect alignment and free movement at low speed before operating at full speed.

Packing

• Item supplied as individual collar, sold per piece.