This is an amazingly helpful, detailed post showing
great edication to quality.
Thank you!
Gordon
--- A440A@aol.com wrote:
> 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
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