Hirobo HI2500086 Ball Bearing 3 x 7 x 3 mm, 2 pcs  [HI2500086]

Micro ball bearing for RC helicopters

This is a compact RC-scale accessory delivered as two pcs of 3 x 7 x 3 mm ball bearings designed for general-purpose use in small helicopter and model assemblies. Keep in mind this product is a replacement part for hobby-grade components and is intended to reduce friction at rotating joints and shaft supports in miniature drivetrains, rotor linkages, and similar subassemblies.

Key practical points for hobby use:

• Size and count: the package contains 2 pcs of 3 x 7 x 3 mm bearings, referenced by model number HI2500086.
• Installation tips: press the bearing into a clean, properly sized bore using a soft driver on the outer race to avoid race damage, avoid direct hammer blows, and check shaft fit for play before final assembly.
• Maintenance: inspect bearings for smooth rotation and contamination, replace when roughness or play appears, and follow your model's recommended lubrication practice after confirming whether the bearing is open, shielded, or sealed.
• Role in tuning: swapping small bearings can reduce unwanted friction and play, contributing to crisper cyclic response and steadier tail or drivetrain operation on micro helicopters and light models.