"Oval or Round Shanks" or to bend or not to bend

[Richard Moody]

----------
> From: Stephen Birkett <birketts@wright.aps.uoguelph.ca>
> To: pianotech@ptg.org
> Subject: Re: "Oval or Round Shanks" or to bend or not to bend
> Date: Friday, September 05, 1997 2:56 AM
> 
> Richard wrote:
> > 	Before time lapse photography, only educated proposals could be
> > made. It was suggested that the optimum blow to the string would
> > occur if the  hammer rebounded at the moment the string was at
the 
> > heighth of its vibration peroid. 
> >
> We now have computer simulation to get a grasp on this. I wish I
could 
> show you the graphs I have in front of me..showing hammerhead
position, 
> string displacement and force during the impact period.
Unfortunately 
> these aren't email-worthy. 

If they can be photocopied, I would pay for that and the snail mail,
or if they have been published, perhaps some references I could input
into a library computer system and maybe get on  interloan. 

 

Richard Moody 

ps  Of course Helmholtz's comments about the hammer leaving the
string at it's apex could be view as predictions since he was before
time lapse photography. On the other hand he didn't say what we know
now that he could have known then is that the piano is a system of
mechanical levers operating in a circular plane exciting a stretched
wire into periodic motion.  So fare thee well into the relms of
trigonometry and analytic geometry those who wish to understand the
piano through graphs, computer simulations and other mathematical
constructs.  Oh and don't forget the levers bend and flex, so it is
also a system of springs. And just when you almost memorized the
string tension formulas, including the gravity correction, don't
forget piano wire is also a spring. You will need that for your
rebound variables. If you have all of that under equation, then you
can procede to the soundboard, if you can factor in the bridge. Now
you are ready to have the old masters tell you where on the string
the hammer of such and such composition should strike.