[pianotech] over centring on bechsteins.

[Overs Pianos]

Lewis,

>I have noticed that all the bechstein actions i have checked always 
>over centre, especially in the treble section?-(Obviously taking 
>hammer wear etc into account).
>
>I assume they set it up this way on purpose for some reason, but i 
>always thought it was best to have the hammer strike the string at 
>90 degrees...?

Many manufacturers bore their hammers short to achieve an 
over-centering action. This does have a friction advantage for many, 
since the contact between the jack and the knuckle is well away from 
the line of centres for most actions. Short boring the hammers will 
bring the contact point closer to the line of centres and will 
slightly reduce action friction - all other factors being similar.

Using a smaller knuckle diameter is another way of helping an 
otherwise ordinary geometry situation. However, one needs to check 
that there remains sufficient adjustment to achieve an appropriately 
close drop height, if considering a smaller knuckle.

Ron O.
-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
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