Hirobo HI2521075 Shaft Collar 3 x 7 x 7 for Hirobo Models  [HI2521075]

Precision shaft collar for RC helicopters

This collar is an RC-scale replacement part listed under general Hirobo helicopter parts, intended as a small shaft collar for positioning and retention tasks on model rotorcraft. The 3 x 7 x 7 marking in the product name denotes the collar sizing convention used to identify its fit and role without implying additional proprietary specifications.

In practical use the collar provides a compact locating element to maintain axial position of shafts and linkages during setup and flight-tuning. Fitment is typically performed using the existing fastening method on the model, and installers should verify axial clearance and alignment before final tightening to avoid binding or slop.

For tuning and maintenance the collar serves as a simple mechanical stop or spacer that can assist with repeatable blade pitch, swash alignment, and rotor head indexing when used in conjunction with the model's original hardware. Keep components clean and check for wear during routine inspections to maintain consistent performance.