Hirobo HI2521066 6 x 8 x 3.5 Shaft Collar for RC Helicopters  [HI2521066]

Compact helicopter shaft collar

This Hirobo collar is a low-profile accessory designed for maintenance and setup of small RC helicopters. The 6 x 8 x 3.5 marking shows bore, outer diameter and thickness so you can match it to hollow shafts and link rods used in model helicopters. It serves as an axial stop to control shaft position and reduce unwanted endplay while leaving rotation unaffected.

Fitting is simple: slide the collar onto the shaft to the desired location and tighten the contact point until the collar sits snug and axial movement is constrained. Verify alignment with nearby linkages and rotor parts before final tightening to avoid binding. As with any model component, confirm fit on your specific shaft before flight use.

During trimming and setup the collar helps keep bearings and links in their intended axial positions, improving repeatability when adjusting controls or swapping parts. It is intended for hobby model helicopter applications only.