Hirobo HI2521086 Collar 12 x 15 x 5 for General Helicopter Parts  [HI2521086]

Precision spacer for rotor shafts

Listed as a general helicopter component from Hirobo, this collar provides a compact locating feature for rotating shafts and linkages in RC helicopter assemblies.

It secures the axial position of parts and reduces lateral play, helping to maintain alignment of blade grips, hubs and bearings while leaving the airframe's dynamic behaviour unchanged when correctly fitted.

To fit, slide the collar to the required location on the shaft, seat it against the adjacent hub or bearing face and fasten using the original set screw or retaining method. Verify that the shaft rotates freely after installation.

Regular maintenance checks are advised: confirm the collar remains seated after flights, examine contact areas for wear, and replace if distortion or excessive play is detected to keep handling predictable.