Today were going to talk about the proper use of thrust bearings for the Xtreme framed V120's.
In case nobody was aware nearly all larger helis use a combination of radial bearings and thrust bearings in the head support. There are plenty of good reasons for this besides the fact that it's the mechanically correct method for reducing friction on a helicopter head.
I decided that the standard issued radial bearings that my Xtreme frame came with weren't doing the best possible job of reducing friction. This was evidenced with the fact that if I over- tightened the collar just a hair it would bind the radial bearings up big time. It made no difference if the tail gear was on or not so this wasn't caused by a gear mesh problem.
This apparent binding, due to side axial loading a radial bearing, is what happens every time you use pitch in either direction. Placing high axial loads on radial bearings is mechanically incorrect, IMO this can lead to premature bearing ware and lots extra friction...more »