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Key Leads and Inertia

John Hartman [link redacted at request of site owner - Jul 25, 2015] [link redacted at request of site owner - Jul 25, 2015]
Mon, 28 Apr 2003 11:01:26 -0400


Stephen Birkett wrote:
>
> 
> Some years back when the list was still innocent we had a discussion of 
> inertia. I recalI pointing out the discrepancy between static balance 
> which depends on the distance to the fulcrum and inertia which depends 
> on the square of the distance.
> 
> Some might argue that the "assistance" provided by the lead in "soft" 
> playing actually makes the action MORE difficult to control.
> 
> Stephen
> 

Stephen,

Thanks for sharing this with us, your insights are very helpful. Maybe 
you can clear something up for me.  In the real word actions and other 
machines have friction. Let's say I measure a note on a grand action and 
find that there is 12g of friction measured statically (D-U/2). When the 
action is played through its dynamic range does the friction go up 
proportionally to the increased force applied to the key?

John Hartman RPT

John Hartman Pianos
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Rebuilding Steinway and Mason & Hamlin
Grand Pianos Since 1979

Piano Technicians Journal
Journal Illustrator/Contributing Editor
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