Hirobo HI2521104 3 X 6 X 12.5S Low-Profile Collar for Helicopter Use  [HI2521104]

Low-Profile Collar for Helicopter Shafts 3 x 6 x 12.5S

Marked HI2521104 by Hirobo, this collar is offered as a replacement component for RC helicopter assemblies where space is limited and a slim clamp is needed. The 3 x 6 x 12.5S notation defines the nominal size for matching with shafts and housings.

Installation begins with a careful inspection of the mating surfaces, removal of dirt and debris, and sliding the collar into the correct axial position before using the model's original retention method. Verify clearance and alignment after fitting to avoid unintended changes in tail or rotor behavior during flight.

For maintenance and tuning, these collars are primarily used to lock axial position and reduce lateral movement in rotating assemblies. Regular checks of fit and position help maintain consistent rotor head geometry and predictable handling characteristics.