3 x 5.2 x 2 Hirobo HI2521085 Collar - Shaft Positioning for RC Helicopters  [HI2521085]

Compact collar for helicopter shaft positioning

The Hirobo item HI2521085 is a shaft collar listed with dimensions 3 x 5.2 x 2 and offered as a generic spare for RC helicopters. The description concentrates on the collar's role in locating and securing rotating parts on model shafts without tying it to a specific airframe or kit.

During servicing and setup this collar is generally used to set or limit axial movement and to register the positions of bearings, pinions, or gears relative to the rotor head. Because only the part code and dimensional callout are supplied, verify the collar against the shaft diameter and the space constraints of your model before fitting.

Fitting guidance: treat this as an aftermarket accessory and use the model's normal securing procedures; avoid forcing the collar onto shafts with mismatched dimensions to prevent deformation. Small collars like the HI2521085 are handy for keeping shaft positions consistent when changing or tuning components.