downbearing direction

[Richard Brekne]

Stéphane Collin wrote:
> 
> Hi Terry.
> 
> In my opinion, the best way to know if hitting the string with the hammer in the direction opposite to that of the bearing of the strings on the bridge has a non negligible effect that would be different from the situation the other way round is to make extensive study with closely controlled trials and well criticised measurements.
> The other way, far easier and cheaper (and also subject to ridiculous errors as well), is to guess with our mental formalizing of the physics involved in the process.
> 
> My try (worth no more than my present formalizing of piano physics, subject to change without notice) :
>

Boy you got that right !! Well said Stéphane

Here's a cute little experiement tho to illustrate a bit of the amount
of force that yanks upwards on the bridge and front pin. Place a penny
(or similiar coin) on the string just front of the bridge so that the
penny is balanced on its thin edge and as close to the bridge pin as
possible. It should balance fairly easily between two strings of a
unison. Then bang on the string with a very hard blow and watch what
happens (how fast and with how much force). Do the same thing for
several strings of various lengths. You might also try placing the penny
up as close to the aggraffes / capo bar as you can to see what happens
there as well... just for fun.

Cheers
RicB