Hirobo HI2521137 Collar 5 x 7 x 2 shaft collar for RC helicopter and scale model assemblies  [HI2521137]

Shaft collar for RC models

This Hirobo HI2521137 collar is an RC-scale shaft collar defined by its 5 x 7 x 2 sizing, intended for use in model helicopters and other scale assemblies where a compact axial clamp is required. It functions as a simple retaining element to hold shafts, spacers, or bearings in position inside tight mechanical stacks.

Installation is straightforward: position the collar at the desired axial location on the shaft, ensure alignment with mating components, and secure per your model's existing fastener method. The part's role is mechanical retention and micro-adjustment of axial clearance rather than load-bearing in high-torque applications, so verify fit and rotational freedom before final assembly.

In tuning and maintenance, use the collar to fine-tune axial endplay or to lock components after shim adjustments. Because this is an RC accessory sized for model-scale systems, check compatibility with your shaft diameters and the surrounding clearance to avoid interference with rotating parts or bearings.