Hirobo HI2521102 5 x 8 x 3.5 Shaft Collar for RC Helicopter Parts  [HI2521102]

Precision shaft collar for helicopter models

This HI2521102 collar from Hirobo is supplied as a compact replacement within the helicopter general-parts range, marked 5 x 8 x 3.5. It serves as a simple mechanical collar to position and retain rotating shafts or spacers in model helicopter assemblies without implying fitment beyond the manufacturer's general parts category.

On the bench, fit the collar to the correct shaft location and secure adjacent hardware to control axial movement. Because this is a component-level item, confirm dimensional fit against the target shaft and follow the fastening method specified by your helicopter's parts layout or service instructions.

For routine maintenance and setup the collar is useful for setting axial spacing between gears or bearings and restoring consistent shaft alignment after disassembly. Keep the part free from grit and verify rotational clearance after installation to avoid binding in the rotor drive or transmission train.