Re: pteros have lift-off

[jrc <jrccea@bellsouth.net>]

The stroke isn't circular, and wingstrokes don't operate chiefly in the 
horizontal plane.  Wingstrokes are quite a 3-D affair with differences that 
vary with airspeed and weight and with allometric differences between 
species.  I usually construct the terrestrial manus stance as being somewhat 
wider than the pedal stance, but that difference isn't particularly 
significant for any reason having to do with launch.  I'm guessing that you 
are seeing the motions of the forelimb joints during the launch as having a 
very different locus than Mike and I do.
JimC

----- Original Message ----- 
From: "David Peters" <davidpeters@att.net>
To: "jrc" <jrccea@bellsouth.net>
Cc: <dinosaur@usc.edu>
Sent: Monday, January 12, 2009 9:38 AM
Subject: Re: pteros have lift-off


> >  Like David M says, think of a pterosaur launch as a modified 
> > downstroke.  The outer wing is already starting to operate as an 
> > opening/lifing device as it begins to unfold very early in the cycle.
>
> A little confused here... at the bottom of the downstroke the wings  are 
> just coming to the end of a chiefly horizontal segment in their  stroke 
> cycle, the south pole of their circular stroke, if you will...  unless the 
> wingstroke only operates chiefly in the horizontal plane.  Maybe this is 
> the key >> do you envision a manus stance much wider  than the pedal 
> stance?