Shanks parallel to strings

[Ron Nossaman]

>  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.

Right, very good. Perpendicular to a line between strike point and hammer 
flange center - universally, regardless of any other detail of action 
setup. Most of the discussions about this sort of stuff are meaningless 
because a lot of pertinent data is either assumed, or ignored. Is it the 
direction of hammer travel that makes a difference in perceived power, or 
the changes in rotational inertia, leverage, friction, flex, or expectation 
that does it, if it is indeed done?


>  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.

I don't think you're missing anything. I don't think it matters a bit (in 
and of itself) at what angle the hammer is glued to the shank, and that any 
performance difference with angle or bore length differences come from the 
rest of the action parts operating within parameters for which they weren't 
designed. The rest of the action, including it's proximity to the strings, 
DETERMINES the optimal (perhaps least bad) angle and bore distance, as the 
clearances within the action cavity and hammer placement , define, 
determine, and limit the action configuration.


>  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).

Or maybe it's one of those clearance problems in the action cavity that 
limits the options and requires a compromise.


>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.

Seems like it should be a good thing, but would need a thoroughly 
re-designed action under it, in a most likely different piano design that 
makes room for the action to go in the piano. The question then is, would 
the presumed goodness be enough (or at all) better in any or all ways to 
justify all the trouble?


>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 don't think of any reason it would. More concerns would become apparent, 
I'm sure, as the action geometry was being worked out in detail.


>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.

Slick! I haven't seen that. Do you recall anything about the hammer to 
shank angle on these?

Ron N