[pianotech] strike line

[John Delacour]

At 13:15 -0800 17/2/10, Delwin D Fandrich wrote:

>Was there a change in there someplace? The only Model C I have notes on had
>a strikeline that was at approximately 2 degrees to the front of the keybed
>(if my notes are correct). The distance from the front of the rim arms to
>the strikepoint of C-88 is about 50 mm shorter than the distance from the
>front of the rim arm to the strikepoint at A-1. Granted this is for an
>88-note piano, but did they change plates and rims when those three extra
>notes were added?

Del, as I said earlier, I can't speak for the model C in particular, 
since it's a long time since I even saw one, and I can't visualize 
it.  My "rationale" was a generalization, which applies to many 
grands -- "on most grand pianos, parallel to the line of the 
key-fronts and hence to the front of the front rail"

If the keys are of reducing or increasing length, as on some 
Blüthners, Kaps etc. then the rule cannot be applied and an 
adjustment needs to be made to take into account the angle of the 
hammer rail to the front of the front rail.

The main point is that the strike line is straight, I think you will 
agree, and that the treble end of it can be determined to within a 
fraction of a millimetre.  If the keys are all the same length and if 
therefore the hammer rail is parallel to the front of the front rail, 
or the key-bottom, then my rule applies.  If not, then other things 
have to be factored in but one way or another it doesn't require 
rocket science to determine where the strike line is meant to be.

JD