Post by dubiousgolfer on Mar 5, 2021 9:00:46 GMT -5
DG,
OK.
Does that explain why the negative MoF is greater near P5 - P5.25 than it is near P4.5 in the following Kwon graph and why it then starts to become less negative between P5.3 => P5.5?
Jeff.
Dr Mann
No, because one needs to use the instantaneous 'magnitude of the net force' x 'the length of the moment arm' .
1. At P4.5 the magnitude of the 'Net Force' is small while the 'length of the moment arm' is large
2. At P5-5.25 the magnitude of the 'Net Force ' is large while the 'length of the moment arm' is small .
From Dr Kwon's graph this means the 'Net Force' x 'length of moment arm' at P5-5.25 is greater than what it was at P4.5 (both in a negative clockwise direction).
So one cannot just use the instantaneous angle between force and clubshaft to assess the magnitude of the MOF, one also has to take into account the instantaneous magnitude of the 'Net Force' and the 'moment arm length ' together. A reader might incorrectly think that increasing the lag angle (ie. beyond 90 degrees) while not increasing the force will create a greater 'Releasing' MOF impetus (which is an incorrect perception as per my diagrams in previous post).
DG
PS. I am suspecting this is why long drivers have to use active positive torque to help 'release' the club when they have very acute lag angles and can't generate enough 'MOF' (ie. the 'Net Force' element).
1. They create large lag angles to keep their MOI small , so that they can generate a lot of hand force via their body pivot torques.
2. The longer they can hold that lag and keep their MOI small, the longer their average hand force along their hand path and the more work energy transferred to the club.
3. As they approach late release with such an acute lag angle (if less than 90 degrees) , they might not have the biomechanical capability to create that 'Net force' with a 'smaller moment arm' to apply the necessary MOF release impetus to maximise clubhead speed by impact (without the assistance of active positive torque via their hands).