S&S D with high strings/low action stack

[John Delacour]

At 12:14 am +0200 10/10/06, StŽphane Collin wrote:

>When boring hammers, should we favor strictly the string heigth 
>minus shank center heigth at the cost of no straight hammer heigth 
>at rest (reflecting the not straight strike line heigth at strings) ?

Broadly speaking I agree with Dale Erwin, as far as he goes, except 
that I aim to have each hammer strike the string at exactly a right 
angle.  I don't follow the reasoning as regards over-centring.  It 
might be argued that the shank bends under a heavy blow and therefore 
tends to cause the hammer head to under-centre slightly, but given 
the rigidity and thickness of modern shanks, particularly the 
hornbeam ones, I doubt if this is significant and would need to see a 
slow motion movie to be convinced.  Nevertheless I think it would be 
a valid research exercise for someone with the equipment, if it 
hasn't already been done.

Let me re-emphasise the importance of taking into account the slope 
of the strings, which is considerable, and most critical, in the high 
treble -- but this slope needs to be measured throughout the scale 
for every piano and factored into the bore angle.  If this is 
ignored, the hammers in the extreme treble will under-centre.

Hammer-heads nowadays are made of a uniform length, at least by all 
the makers I use (Imadegawa, Abel, Renner) and if you examine hammers 
from the good old days you will discover that this was not the rule 
then and that account used to be taken of the arching of the strike 
line.  The length of the head should be such that the tail hits the 
check at the same height throughout the scale.

>Also, when gluing hammers on shanks, should we favor the hammer 
>crowns straight line at rest, at the cost of aural best position ?

If you give each note the same blow (and hence the same touch depth), 
the crowns will rest in a line parallel to the string-height line.

>In other words, how much should we care about aesthetics when doing 
>hammer work

Aesthetics is a broad concept and applies to function and design in 
all its aspects.  There is nothing intrinsically beautiful about a 
straight line, as any  ancient Greek architect could tell you.  Is a 
clothes-line or a telegraph wire intrinsically ugly? :-)

JD