Hang'n dem Hammers

[A440A@aol.com]

I posted: 
>"This comes from hanging trial hammers in the middle of the section and
> >moving the action in and out to find the best contact point on the string."
 
Alan writes: 
>Moving the action in and out?
 >I've seen curved hammer lines to accomodate the dampers. What does that
>do to ideal strike points?

(Hmm,  I must apologize for not stipulating that I was referring to grand 
actions,  the upright action must be raised and lowered to analyze the same 
question.)

       On a Steinway grand, the hammers are usually hung 130 mm from the 
center pin.  So, it is a simple matter to have a set of trial hammers, of 
varying bore lengths, hung at this distance, at exactly 90 degrees to their 
shank.   I use them find what bore distance allows the hammer to meet the 
string at 90 degrees. ( I do this with a small square on the strings against 
which the hammers, with their centerlines marked, are compared when they 
touch the string).   Then I bore the set and install the end hammers in each 
section at 130 mm.  I put the action in the piano and listen to changes as 
the action moves in or out.  If it improves the sound of a section to pull 
the action out 2 mm,  I simply hang the hammers in that section at 132 mm.  
Sometimes I find that the middle of a section needs to be farther out than 
the ends, so I make a note of this  and hang by the following procedure:  
    In the upper sections, I  put a hammer in the middle of the section and 
listen as it is moved in or out.  This is where I find that hammer lines can 
produce better sound when curved within a section, but it usually turns out 
that the curve is gradual within any given section.  Separate sections under 
the V-bar usually have their own distinctive "best" hanging distance.  
   These curved hammer lines are not easily replicated on jigs with straight 
edges, so I usually have one or two hammers within the section that are 
indexed to the optimum contact spot, and then hang the hammers in straight 
lines between them. At some point, the time it takes to refine the contact 
points to the last 1/2 mm is not worth it.  Hammers can be finely adjusted to 
these tolerances with a little heat and a vertical bend in the shank, if 
necessary.  Even a very slight asymmetry in filing can move contact back or 
forth, so I just hang straight between guides that are perhaps 10 hammers 
apart.  
   I also begin a replacement job with the hammer shanks all traveling 
straight up and down, as measured by a square sitting on the whippen rail. I 
space the shanks to begin their arc from directly over the whippen flange 
screw and with equal distance between them at the knuckle.  This provides a 
beginning alignment "framework" so that when decisions have to be made, I 
know where I can safely depart from "ideal". 
     I often find that grands require the bass hammers to be moved leftward, 
and the middle section must be spaced to the right if I am to have all the 
top end directly under the strings and directly over the whippen.  By 
starting off with everything straight, I know how to split the difference so 
that nobody is way off center,(which would require excessive spacing of 
whippens, which leads to problems if the capstans are  not perfectly aligned, 
and the same goes for the let-off buttons). 
    I hate to burn shanks,(though I do), so I really want to know that they 
are traveling straight before the hammers go on them.  Also, especially in 
regard to Steinways, once I know that they are traveling straight,  I know 
that I can space them with two equal-sized shims of brown paper tape used on 
the diagonal and not change the traveling.  This is, ultimately, a time saver 
when the greatest degree of perfection is the goal.  
     Sometimes it helps the speed of Steinway regulation to combine the 
spacing and traveling, ie, if you know the hammer needs to strike farther to 
the left, and it is traveling to the right, a simple spacing paper on the 
right side of the flange will cure both at once.  And, if it is traveling 
right, and hits the string just right, the Steinway flange allows one to shim 
just the front right corner, so that the shank travels more to the left, but 
the flange is swung to the right, keeping the contact correct, while making 
the hammer travel straight up.  
Regards, 
Ed Foote RPT