[CAUT] Down Weight Too High With New Hammers

Fred Sturm fssturm at unm.edu
Wed Aug 25 21:02:09 MDT 2010


On Aug 25, 2010, at 7:47 PM, Paul Milesi, RPT wrote:

> when you say that "what was accelerated was the ratio, in theory," do
> you mean to say that the ratio was increased?  In other words, it  
> might go
> from 1:4.9 up to 1:5 as the key is depressed?


	Actually this occurs with any piano key. It doesn't pivot on a sharp  
fulcrum, it squishes on some felt. The pivot point moves toward the  
front of the key. If you take standard punchings and trim the side  
toward the front of the key, you'll find the ratio (measured most  
easily by DW) goes down, which is another way of saying that having  
the felt there in front must have been increasing the ratio as the key  
was depressed. The key rides up and down the keypin a bit every time  
it is played. It's another one of those things where the closer you  
look the less precise it becomes - we are told to measure key ratio to  
the middle of the balance hole, but it ain't so, nor is the  
termination of a piano string the tangent or middle of a bridge pin.
Regards,
Fred Sturm
fssturm at unm.edu
http://www.youtube.com/fredsturm



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