HIROBO HI2521101 3 x 4 x 3.5mm Collar for Precise RC Link Spacing  [HI2521101]

Miniature collar for precise link spacing

This RC-scale collar serves as a small spacer for helicopter linkages and similar miniature assemblies where accurate clearance is important. Offered as a neutral replacement accessory for model upkeep, it is not designed for full-size machinery. The collar helps preserve consistent distances between shafts and link ends and keeps small pins located during cyclic or pitch adjustments.

Material and fit: nylon construction gives the collar low friction and modest wear resistance suitable for light mechanical connections such as swash links and rotor head joints. The material reduces the chance of sticking against metal pins and supports smooth motion where narrow tolerances are needed.

Installation notes: clean the mating shaft and pin before fitting, slide the collar into position until it seats against the shoulder, then verify that the linked parts move freely. If unwanted play remains, check pin diameter and seating surfaces rather than forcing a mismatched collar. The part functions as a passive spacer; follow torque recommendations for adjacent fasteners.

Tuning role: use these collars to make small spacing adjustments that reduce slop and help keep lever lengths consistent across link sets. Best results come when the collar is used alongside correct link geometry and control throw settings.