Richard Wilson wrote,
 
>  Regarding the excellent debate on rigidity of cast iron being 'fathered'
>  by Doug Dawson.....
> 
>  
>  > deflect the surface .003.
>  ....
>  >.. checked it out on a #8.  Sure enough!  .. I got .004" with 10
>  >lbs.)
> 
>  > so I feel pretty safe here, pressure applied to the tote during
>  > planing would present a downwards force virtually equidistant from
>  > both ends.  And that's only the vector component directly into > the
>  wood
> 
>  Q1)  Can I take it that, when using a No 8, I can bend it by 3 - 4
>       thou?

   It seems like you can, i.e. that's what people are measuring,
   more or less, _provided_ you apply the requisite amount of
   downward pressure, which was ten pounds in that case.  I chose
   that figure, because I kind of doubt that people would ever be
   applying _more_ than that, _downwards_, during normal planing.
   Remembering that we're usually applying force to the plane
   during planing, in a downwards/forwards direction, the
   downwards force will typically ( methinks ) be no more than
   half the total applied force.  Think of pushing a 30 pound
   weight around for some length of time...  It's semi-clear to
   me that that's the upper limit of what we'd be willing to
   tolerate for an supposedly functioning plane.  But I could be
   wrong!  I.e., I don't have the measuring apparatus to determine
   how much force I'm applying to a plane in use.  Anybody willing
   to do some experiments on this, by all means we'd be grateful
   for you're help.

>       What happens when, at the final stroke, I let the plane
>       caress the surface, doing my best to apply only forwards
>       pressure.?
 
   We're working up to that...  but flexure is not gonna be a
   primary factor in what happens in that specific case, it would
   seem.
 
>  Q2)  Can I scale the result down for shorter planes?  a No 4, for
>       instance will apparently stay as near as dammit to being flat.
>       Which is what I want my smoother to be.

   No scaling at this point, for the shorter planes.  The results
   were for planes with a centrally located tote, rather than 
   something with an end-mounted tote like on the #4.  That still
   has to be worked out.
 
>  (Lumpy solers disregard last sentence)
> 
>  Richard Wilson
>  who is lost in admiration at the content of this thread.

   Just say, lumpysolers, flatsolers, it doesn't matter, if all
   we're interested in is the truth.

   Doug Dawson
   dawson@p...