[airair]

http://www.lynnblakegolf.com/forum/thread5918.html

Originally Posted by Martee

Here are my pics: Horizontal Hinge Action Horizontal Plane of Motion Hinge Pin Vertical (Perpendicular) to the Horizontal Plane Vertical Hinge Action Vertical Plane of Motion Hinge Pin Vertical (Perpendicular) to the Vertical Plane Angled Hinge Action Angled Plane of Motion Hinge Pin Vertical (Perpendicular) to an Angled Plane

Okay, Martee. Terrific pictures! I've edited the captions in your Quote above and they are now "picture perfect!" They will help everybody a lot.

Now, in your PM, your thought was that the vertical hinge action (#2 photo) requires a Horizontal pin. And I can clearly see where you are coming from: The pin is aligned horizontally if you view it only in relation to itself. Clearly, the pin is horizontal.

But...here's the key:

We're not looking at it that way! We're looking at the pin in relation to its associated Plane of Motion. In this case, that is the vertical plane of motion. And relative to that plane, the pin is vertical, or to use your very good word, perpendicular, to the vertical plane of motion. [As a matter of fact, 'perpendicular is so good that I'm going to edit my post to use it instead of the 'at right angles' to. Same thing, of course, but better said.]

So, no matter which of the Three Basic Planes of Motion is illustrated, the hinge pin is always vertical to its associated plane:

-- Vertical to the horizontal plane;

-- Vertical to the vertical plane;

-- Vertical to the angled plane.


The pin is never horizontal to any one of the three planes. It is always vertical! All you do to achieve any one of the three basic planes of motion is to mount the hinge pin vertical to the plane of motion desired.

Do you see it now? This is a really important point because pretty soon we'll be learning to use our Flat Left Wrist to duplicate the motion of a hinge by keeping it vertical to one of these three basic planes.

Thanks again for the pictures. They're great.

We're on the right track now!