[TowerTalk] flexible mast coupling

[Bob K6UJ]

As I see my stack of beams swinging back and forth in the wind I am thinking about adding a flexible shaft coupling above the rotor
to absorb the shock,  I have read somewhere about using automotive drive shaft flex couplings and adapt them to clamp on to 
our 2" masts.  I used to have one of Bill Orr, W6SAI books on antennas and if I remember right he used one for a Volvo, and it
had a rubber donut between two flanges.  Anyone make a flexible coupler for their mast and would share what you used ?

Bob
K6UJ