I understand your idea of the COG of the clubhead and I have no problem understanding the lathe example. I also can understand Toolish's comment about how the hosel twists around the COG of the clubhead when one twirls the vertical club. I don't disagree with all these points. I can even agree that PP#3 traces the SPL through the sweetspot when the clubhead in the immediate vicinity of ball impact (when the clubhead has rotated so that there is a small, but significant, difference between the sweetspot plane and the clubshaft plane).
What I cannot understand is what relevance these "facts" really have with respect to the golf swing. I never sense the hosel rotating around the sweetspot-PP#3 axis in a golf swing. I can only sense the clubface closing and opening, and it "feels" like the clubface is rotating around the clubshaft axis. It is my present belief that the reason why I harbor this "belief" is that I presently believe that natural human biomechanical actions dictate opening of the clubface opening in the backswing and clubface closing in the downswing/followthrough, and that these actions have no necessary causal connection with the idea of there being a axis between the sweetspot and PP#3. However, I am open to new insights.
I can understand why human beings open the clubface in the backswing, because the left wrist has to remain flat and the left arm has to rotate clockwise in the backswing to get the left hand to the usual end-backswing position. However, I do not know whether the Robot-Fit type machine also rotates the clubface that much in the backswing, and if it does, how it gets the clubface to rotate back to square by impact if the wrist joint simply consists of two enmeshing gears that operate passively in response to centrifugal release forces.
Threaded Mode
