Hirobo HI2521126 Collar 5 x 6-8 x 14  [HI2521126]

Helicopter collar for shaft positioning

This collar is an RC-scale replacement part intended for helicopter general parts and maintenance tasks. Its designation reflects the nominal bore and axial length, making it useful where a compact collar is needed to register or retain rotating shafts within the rotor linkages or transmission stack.

Installation is straightforward: slide the collar onto the shaft to the desired axial position and secure it according to your model's existing retention method. It functions as a locating and spacing element rather than a load-bearing gear, so alignment and fit are the key tuning considerations during assembly.

In tuning and setup, collars of this form help preserve axial play, maintain concentric alignment between mating components, and simplify repeatable reassembly after maintenance. Check shaft surface condition and mating bore fit before final installation to avoid introducing runout.