I have an original NN3 that has served me well, and could continue to do so. However, recently I have been having a problem with the upper rotator becoming loose with respect to the upper arm. This is attached to the upper arm by means of a stepped diameter threaded bolt, and is tensioned against the upper arm by two allen-head set screws. The bolt doesn't have any tool socket on the head (it is completely flat), so there is no way to tighten the rotator firmly against the upper arm; I can hand-tighten it by turning the threaded end and tightening the set screws, but that's it. It appears that after a short period of use, loosening the upper arm knob and adjusting the pitch of the upper arm begins to turn this bolt within the rotator and loosen it. The result is that the set screws are no longer tight against the upper arm, and the upper arm sags and wobbles.

I'd be happy to buy a replacement upper arm rotator assembly or even an entire upper arm assembly if it would solve this problem. But there is apparently no way to buy either on the Nodal Ninja store NN3 accessories page (http://store.nodalninja.com/categori...r-NN3-series-/). There is a NN3 MkII upper arm/rotator assembly, but it isn't clear whether this is the same as the NN3 arm or if it would mate with the NN3 vertical rail. Can anyone confirm whether or not this would work? (Also, while there are two listings for an NN3 index ring, there is none for a Mk II index ring. Again, are they the same?)

If I can't get a replacement rotator or arm, I'm inclined to just lock-tite the rotator to the arm and be done with it. Any downside to just doing that?