Helicopter Collar 3 x 6 x 17 mm HI2521076 by Hirobo  [HI2521076]

Spacer role in small assemblies

This Hirobo HI2521076 collar is a 3x6x17 mm precision spacer intended for hobby helicopter mechanical layouts. It is used to hold components in axial position within confined assemblies where accurate spacing is needed.

To install, verify shaft and bore dimensions, press the collar squarely using controlled force or tap lightly to avoid distortion, and confirm component alignment after installation. The collar acts as a passive tuning element by preserving gear and bearing spacing, which can improve tracking and reduce side-to-side play.

Include the collar in routine inspections; check for any loss of roundness or corrosion and replace the part if fit or integrity is degraded to maintain predictable shaft performance.