[Martee]

Homer Kelley introduced the Pivot Swing Center Tripod concept in his additions to the as-yet-unpublished 7th edition. Previous editions had only the photo sequences of 9-1 and 9-2 where a white reference marker was placed behind the head to show its centered location.

I quoted that concept a few days ago in the Forum TGM Advanced and the thread 9-1-5...Pics, my post #143. Here it is again:

"The important thing is that the true Swing Center -- for all components -- is around a Hinge Pin with one end at the top of the Stationary Head and the other in the ground precisely between the Feet, with no regard for Body Location or Position at any time."

So, the top of the Tripod is the Stationary Head and the base consists of the two Feet and the centered Hinge Pin falling precisely between them.

Thanks, need to look at those notes, it has been a long time.

So the answer to #1 is that this is in the upcoming edition (ted indicated such).

The definition or descriptive text doesn't meet the definition of a tripod (a three legged support). Any attempt to use a line down to the base line (line between the feet) is not a leg but bisecting line (three is a name for this, I can't recall) which divides the base line into two equal segments. Now if this bisecting line forms two rt triangles on the base, then this is an isoscele triangle, otherwise it is just a non right triangle. There is no requirement that I know of that would make this an isosceles triangle, since you can bend the knees, spread the feet, all of which will move the apex, the pivot center and change the length of lines between the feet to the apex.

The defintion or descriptive text does define the pivot center to between the feet, in the middle.

This being defined to be percisely between the feet, well it is troublesome, it seems to me that ball position, feet separation, etc all seem to take on more a standard position based on this defintion.

Did Homer update or change the glossary to add some words to explain this 'tripod'?

This is confusing, Homer did what I thought was a great job on explaining and showing the 'Triangle Assembly', I would think that this would merit the same level of detail.