Rudder Stock Play?

[Tim Good]

My rudder stuck has a small amount of play. It has half way down it 2 threaded slots which take an M12 grub screw. I assume these tighter down into a shaft key of some sort. Without the grub screws the rudder is still secure but with the grub screws tightened the play disappears.



1. Do you agree these grubs are likely to tighten down a shaft key?

2. These grub screws work loose and the play comes back into the rudder after a few months. Any suggestions? I've tried locktight but I haven't cracked them to 70nm as suggested for an m12 stainless a70 bolt.

 

[Neil_Y]

Use epoxy, just araldite will prevent the grub screws coming loose.
Precision or 2011 grade has a low melting point so to remove you can make it easier by heating the metal work.