Method and apparatus for dynamically locating neutral shaft plane

Apparatus for dynamically locating the neutral plane of an elongated flexible shaft having a butt end portion and a tip end portion, comprising:

• a base;
• a base plate mounted on said base for rotation about a predetermined axis of rotation said base plate projecting generally radially from said axis of rotation;
• a clamping mechanism carried by said base plate and including a clamp block on said base plate, a clamp member mounted in said block and having a bore having a central axis that extends radially relative to said axis of rotation to receive the butt end portion of a shaft with the longitudinal axis of the shaft extending along said central axis, said clamp member being selectively engageable and disengageable with a shaft in said bore to hold the shaft in said clamping mechanism with the tip end portion projecting radially outwardly from the clamping mechanism, and anti-friction bearings mounting said clamp member on said block for free rotation about said central axis;
• a motor for rotating said base plate about said axis of rotation and swinging said shaft about said axis of rotation at a sufficient speed to cause the shaft to bend under the inertial load on the shaft, thereby causing said clamp member and the shaft to rotate in the clamp block into an angular position about said central axis in which the neutral plane of the shaft is aligned with the plane of rotation of the shaft;
• and a brake mechanism that is selectively operable during rotation of said base plate and of the shaft in the clamping mechanism to fix the angular position of the shaft while the neutral plane of the shaft is aligned with the plane of rotation.

Apparatus for dynamically locating the neutral bending plane of an elongated flexible shaft, comprising:

• a base;
• a fixture having a clamping mechanism for gripping and holding one end portion of the shaft with the opposite end portion projecting away from the fixture, said clamping mechanism including a clamp member that is freely rotatable on the fixture about the longitudinal axis of the shaft to permit the shaft to turn about its axis relative to the fixture;
• and said fixture being supported on said base for movement relative to the base in a preselected manner to move the shaft along a predetermined path extending transversely of the shaft;
• and a power actuator for driving said fixture to move the shaft with sufficient force to simulate the movement of a shaft during a golf stroke and cause the shaft to bend under the inertial load on the shaft, thereby causing the shaft to rotate the clamp member in the fixture into an angular position in which the neutral plane of the shaft is aligned with said path, thereby locating said plane.