Shanks parallel to strings

[Phillip Ford]

Phil Ford (that's me) wrote:
>>   I can see reasons for having the hammer strike perpendicular to the 
>> string line.  But I don't see any good reason for having the hammer 
>> perpendicular to the shank or the shank parallel to the string.  Reasons 
>> given in the archives or the journal for not permitting non-parallel 
>> shanks are along the lines of:
>
>The ideal might be more like the shank canter pin being as close as 
>possible to the height of the hammer/string contact point. That's the only 
>way the hammer will be hitting the string square. With the shank parallel 
>to the string at hammer contact, the hammer is moving forward when it hits 
>the string, even if the hammer head is perpendicular.

I agree Ron.  And this seems to be a point that some people fail to 
see.  They assume that because the hammer is square to the string when it 
hits that the direction of travel of the tip of the hammer is perpendicular 
to the string.  It's not.  It's moving forward as well as up, as you say 
(or in other words it's moving perpendicular to a line between the strike 
point and the hammer flange center.

>  Anything else is mostly a matter of getting the available parts to clear 
> one another and work together both within the action, and with the action 
> in the piano.

I think I agree.  I don't see any structural reason for the hammer to be 
square to the shank.  It's not clear to me that a shank that's not
parallel at strike degrades performance.  Perhaps there's something I'm missing.

>  Invent new action parts, re-arrange the pinblock to get a taller action 
> under it, and you can get the hammer to hit the strings both square to 
> the string, and from a DIRECTION or VECTOR that's also nearly 
> perpendicular to the string - which isn't possible with the current 
> action design.
>
>No?
>
>Ron N

Yes.  An interesting idea.  For the shorter notes (where the hammer center 
falls outside the speaking length of the string, if you were clever, you 
might be able to get the hammer center to lay on the string plane.  For the 
longer notes I can't imagine how you would physically get the hammer center 
on the string plane, since the hammer flange would be where the string 
wants to be (but maybe that just reveals my lack of imagination).  But you 
might be able to get pretty close.  And the closer you get the more square 
the hammer tip is going to be traveling to the string at impact, which 
would seem to be a good thing.  Also, a design of this sort would necessitate
a shank that is way below parallel at strike.  Would this be a bad thing?  I don't
see why it would need to be if the rest of the action were designed around it.

I've seen some old european pianos in which 
the keyframe and keybed are set up so that when you slide the action into 
the action cavity the action is low enough to clear the pinblock but as you 
push it back the action climbs up a ramp so that its final position is 
higher.  I assumed it was one designer's take on this.


Phil Ford