[pianotech] Cresendo Punchings was RE: Hammer Blow

[David Love]

Assuming that it's disengaged when the key hits the punching.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Thursday, October 11, 2012 7:49 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Cresendo Punchings was RE: Hammer Blow

On 10/11/2012 9:25 AM, David Love wrote:
> Might be a sort of catapult effect.  The more abrupt stopping of the 
> key while the chain of levers is still engaged catapults the hammer 
> into the string with a bit more force than it would otherwise.  
> Someone who understands the physics of catapults might need want to 
> comment.  Outside my own ken.

The catapult rock, like the piano hammer, doesn't care what the levers are
doing after it's disengaged from the leverage. If the keys are flexible
enough to be bottomed out on the punching before letoff occurs, this might
well be a reasonable explanation, but then the action has other significant
problems than front punching density.

If the rock is still connected to the catapult at the end of the stroke, I
hope to not be anywhere near the thing when it smashes itself to splinters.

No expert, but I've slung a lot of rocks with various contraptions back in
the misty past.
Ron N