Half punchings on balance rail

[Cy Shuster]

Does this have any similarity to the S&S "accelerated action"?  I can't
remember the details, but I think there's some angled part right at the key
fulcrum.

--Cy Shuster--
Bluefield, WV

----- Original Message ----- 
From: "V T" <pianovt@yahoo.com>
To: <pianotech@ptg.org>
Sent: Tuesday, September 07, 2004 9:42 PM
Subject: Half punchings on balance rail


> Hello Bob,
>
> That makes perfect sense - by changing the fulcrum
> point, you are changing the overall action ratio.  The
> number of interest is the Balance Weight (DW+UW)/2,
> and that has to drop when the action ratio drops.  In
> other words, it will take less force to push the key
> down when the ratio is smaller.  Note that the
> friction, which is (DW-UW)/2, stays approximately
> constant (very slight change).
>
> Best regards,
>
> Vladan