Be careful, the only CDR rotor I know of that had the clunking controller
was the ar22. This rotor was decidedly light weight and had no brake, it
also if I remember right, used only 4 wires, not the std 8 used by the
ham-m etc series. The other clue is that the ar22 is brakeless and
therefore does not have the bottom housing that holds the brake assembly.
I used an ar22 to turn a th3 (small 3 el tribander)_ and it would pinwheel
in the wind and get out of sync with its indicator.
Anyway, hope this helps.