[pianotech] An alternative to cutting the balance rail punching; was best way to change touch on Yamaha grand

[David Love]

That's clever.  The question I would have is whether it's stable over time.
Does the increased pressure on the back of the punching eventually lead to
compression on that side until once again the key lays flat across the
entire punching (though I notice in this case you are using a relatively
thin BRP as I do?  Otherwise, that might not take that long.  With the cut
punching there is no front of the punching to come in contact with the
bottom of the key again regardless of the amount of compression.  Similarly,
with my suggestion the coving would be offset enough that such a change is
not likely to take place.

David Love
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of David Stanwood
Sent: Thursday, February 11, 2010 11:00 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] An alternative to cutting the balance rail
punching; was best way to change touch on Yamaha grand

David,

I've seen this done on a Clementi piano...  c1812

I still like the veneer method best:

http://server2.goffgrafix.com/~stanwood/RatioShim.htm

least invasive.. most reversible...

David S

>I was thinking about this procedure and it occurred to me that you 
>could simply rout out a shallow "u" shape right in front of the 
>balance rail hole on the bottom of the key.  <snip>
>David Love
>www.davidlovepianos.com