The linkage of the tail rotor is affected by the face clearance of servo gears, by the bellcrank and by the pushrod. Minimal play can arise from the face clearance of the servo gears as well as from the necessary freedom of movement for the ball at the bellcrank.
With the screw fitting pushrod connector the pushrod still is adjusted without play. The face clearance of the servo and the ball movement on the bellcrank can not and may not suppressed direct.
Remaining play is balanced by the return spring, if it is installed between tail rotor hub and control bridge. The spring force is dimensioned so that the force of the servo exceeds it, but the control bridge is held play free at the same time.
Return spring, chromed, pack of 2, for 5 mm ∅ tail rotor shaft