Tail Rotor Hub Tip

2006 Jan 27

1) Apply Loctite Adhesive prior to installing the 3mm self locking nut.
2) "DO NOT OVER TIGHTEN". To prevent the allen set screw from mechanical stress, stop tightening the 3mm self locking nut upon contact of the tail rotor inner bearing race.

There have been reports of the M3x18mm set screw on the tail rotor hub (PV0151) breaking, thus causing the model to pirouette out of control.

The cause of this issue can be attributed by the application of excessive amount of torque applied when tightening the self locking nut or an out of balanced tail rotor (vibration).

It is more predominantly caused by over torque of the M3x18mm set screw, as this is evident on new machines with hardly any time on them.

When installing the self locking nut, apply loctite adhesive and DO NOT over torque the self locking nut. Stop tightening when the self locking nut mechanically contacts the tail rotor bearings. Failure to do so will fatigue the M3x18mm set screw causing the set screw to shear off during flight.

1) Remove this link and check for a notchy tail rotor bearing assembly. Back off the tail housing 2.6 X 10mm hex screws if the tail rotor bearings have any indication of a notchy feeling when the tail housing assembly is rotated.
2) 2.6 X 10mm Hex Screws.
3) Tail rotor bearings.

When installing the tail pitch housing (tail rotor blade grips), over tightening of the 2.6 x 10mm hex screws will cause the bearings to become notchy.

Although there have been rare instances where this has been an issue, it is advisable to ensure that the tail bearings rotate frictionless.

To verify this, disconnect the tail pitch control link from the tail pitch housing. Rotate the tail pitch housing and ensure a smooth rotation. Back off the hex screws if the bearings have any indication of a notchy feeling.

For an upgrade version, PV0499 is a one piece stainless steel tail rotor hub that eliminates the M3x18mm set screw.

With this upgrade, the tail rotor section can be disassembled as an assembly unit, without the removal of the tail blades and blade grip housing.

Perform routine a preflight checks on the tail rotor hub for any signs of a black oily film. This is an indication that the tail hub is loose and must be re-secured.

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