Yes , I meant to say Horizontal not Vertical . Thanks Air.
I know for a fact that O.B. Left understands the Hinge Actions and Rhythm. He learned it one-on-one with me and has demonstrated it to me (and others!) many times. However, I used his typo as an opportunity to 'fill in the blanks' for those new to our concepts.
Re-reading my post #14 above -- and substituting "Horizontal" for "Vertical" in O.B.'s post --I can see where his question arose. The writing wasn't as clear as it might have been. Only a guy with O.B.'s in depth understanding could have asked for clarification in my post as written.
Got grandkids all over me at the moment . . . "Poppy!!"