Finding the strike line another method

[John Delacour]

At 6:52 pm -0700 25/7/07, David Love wrote:

>So youÕve obviously found some consistency in this requirement.  I 
>guess it makes sense since I would presume itÕs related to the plate 
>design or casting.  Looking back, though, IÕm not sure IÕve seen the 
>need in every example.  Maybe itÕs time to go back and visit those 
>pianosÉmaybe later.

In theory the strike point will be at a certain fraction of the 
speaking length, say 1/8 in the area under discussion, and since the 
strike line is the first line drawn in designing a piano, it would be 
very odd to think it was not drawn straight in the horizontal plane. 
When you, or Dale, have set up the piano with the curve in the line 
to get the best tonal result, do you find that the hammer is striking 
the string at different proportions of the speaking length? 
Supposing that the strike line is straight, it would take a very 
large error in the casting to require a difference of 4 mm in the 
positioning of the hammer-head on the shank.

Am I right in assuming that Steinway's original set-up has the 
hammer-line straight?  If so, is there a curve in the string height 
or the hammer bore such that the strike point is on the strike line? 
I have practically no experience with the 'B' and am fascinated to 
know why it is that a curve in the hammer gluing should produce the 
best sound to your ears, which I do not doubt.

JD