Hirobo HI2521111 Collar 5 x 7 x 13.2  [HI2521111]

Helicopter collar for shaft alignment

This collar is presented as a small-scale accessory for RC helicopters, matching the 5 x 7 x 13.2 designation in the product title. It serves as a radial locating and retention element on shafts and linkages where a compact mechanical stop or spacer is required.

Installation is straightforward in typical model workflows: the collar slides onto the shaft to establish axial position, then is retained by the chosen fixing method compatible with your model (set screw, circlip, or adhesive as applicable). When tuning rotor play or linkage end float, use the collar to set repeatable limits and reduce axial movement that can affect trim.

As a simple, lightweight part, the collar is useful for maintenance and minor adjustments rather than for primary structural loads, and it integrates into common assembly and balancing routines for small-scale helicopters.