[pianotech] D Hammers

[David Love]

This is not atypical with NY Steinways and varying the hanging distance from
130mm is the most common and the simplest solution.  Sometimes it's
necessary even within the same section (especially the first capo section)
in order to get the hammers to strike the strings at the correct strike
point (the curved strikeline as has been mentioned periodically).  I guess
the question is whether it's been done by design or execution.  I think it's
probably the later.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Tuesday, April 20, 2010 1:31 PM
To: pianotech at ptg.org
Subject: [pianotech] D Hammers


I've bored the hammers for the 1970 D and will be fitting them 
tomorrow.  Perhaps this time I will solve a question that has puzzled 
me most of my career.

In the middle and the treble, with the heads at 90° in both planes, 
the bore length properly adapted to the strike height and the 
moulding centre-line at 130mm from the hammer centre, the hammer 
strikes perfectly on the strike line with the key-block adjusted to 
roughly a middle position.

In order to strike on the line in the bass and low tenor with the 
same 130mm shank measurement I would have either a) to move the whole 
keyboard and action outwards several millimetres at the bass or b) 
reposition the action a few millimeters forward on the key-frame. 
Option b is excluded because it would too much affect the geometry of 
the action, increasing the leverage and the touch weight.  Option a 
would mean a bit of work on the bass key-block and the key-slip, but 
the keyboard front rail would not be quite parallel to the front of 
the key-bottom.

The easiest, and probably the 'standard' way to do things is to 
reduce the shank measurement by the required amount and forget about 
adhering religiously to 130mm, and that is what I'll do unless 
someone comes up with an answer to the puzzle that has never occurred 
to me.

But in order to strike on the line the heads in the bass will need to 
be angled slightly to the right and in the tenor slightly to the 
left, which is to say that the hammer rail is not drilled to the 
strike-points, and this is the question :  did Theodore Steinway have 
a good scientific reason for not doing so.  Did he believe that the 
greater the bore angle of the hammer and the angle of the strings the 
more the hammer-head needs to be rotated on the shank?  Was he right, 
and if so, why does no other maker, so far as I know, do the same?

JD