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<DIV><SPAN class=734354202-20092006><FONT face=Arial color=#0000ff>Just to
correct you David, it's not the hammer that we are traveling, it's the shank and
flange. This is easy to understand if you just imagine the center pin to be a
hinge. When the hinges are not all aligned, the shanks are going to come up all
over the place.</FONT></SPAN></DIV>
<DIV><SPAN class=734354202-20092006><FONT face=Arial
color=#0000ff></FONT></SPAN> </DIV>
<DIV><SPAN class=734354202-20092006><FONT face=Arial
color=#0000ff>Marcel</FONT></SPAN></DIV>
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<DIV class=OutlookMessageHeader lang=fr dir=ltr align=left><FONT
face=Tahoma>-----Message d'origine-----<BR><B>De :</B>
pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] <B>De la part
de</B> David Ilvedson<BR><B>Envoyé :</B> 19 septembre 2006
22:26<BR><B>À :</B> pianoguru@earthlink.net;
pianotech@ptg.org<BR><B>Objet :</B> RE: hammer
travel<BR><BR></FONT></DIV>
<P>Frank,</P>
<P> </P>
<P>When I talk about traveling, I'm not talking about does it look like it's
moving one way or the other. Does the space on one side of the
hammer compress and other expand? If so, you need to travel that
hammer. <BR><BR>David Ilvedson, RPT<BR>Pacifica, CA
94044<BR><BR><BR></P>
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<HR>
Original message<BR>From: "Frank Emerson" <PIANOGURU@EARTHLINK.NET><BR>To:
"ilvey@sbcglobal.net, "Pianotech List" <PIANOTECH@PTG.ORG><BR>Received:
9/19/2006 9:57:56 AM<BR>Subject: RE: hammer travel<BR><BR>
<DIV>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt" align=left><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">If all shanks are
perfectly traveled, and all hammers mounted perfectly perpendicular to the
keybed, while the shanks are parallel to the keybed, the bass hammers will
APPEAR to travel to the bass. The lower tenor hammers will appear to
travel to the treble. This is a function of the angle of the hammer bore
and the width of the larger hammers toward the bass. Once you get into
the treble where the hammers are bored parallel to the sides of the
hammer, they will appear to be as perfectly spaced when one is raised
between its neighbors, as it did with all the hammers were at
rest. </SPAN><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'; mso-fareast-font-family: 'Arial Unicode MS'; mso-bidi-font-family: 'Arial Unicode MS'"><o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">Next time you replace a
set of hammers, try this. Knurl the shanks for note 1, 2, and 3 just
enough so that their respective hammers fit with sufficient friction that the
hammers will stay in place without gluing.<SPAN
style="mso-spacerun: yes"> </SPAN>Do not taper the hammer tails
yet.<SPAN style="mso-spacerun: yes"> </SPAN>Mount the shanks for these
three hammers.<SPAN style="mso-spacerun: yes"> </SPAN>Travel the shanks
as perfectly as you can.<SPAN style="mso-spacerun: yes"> </SPAN>Mount
the first three hammers on these shanks.<SPAN style="mso-spacerun: yes">
</SPAN>Position these hammers along the shank to the achieve the correct
strike point.<SPAN style="mso-spacerun: yes"> </SPAN>Rotate the hammers
on the shank so that the center lines of the hammers are plumb, and
perpendicular to the keybed, while the shank is parallel t! o the keybed.<SPAN
style="mso-spacerun: yes"> </SPAN>Verify that the spacing between the
first and second hammers, is the same as between the second and third
hammers.<SPAN style="mso-spacerun: yes"> </SPAN>With the first three
hammers dry fitted in this fashion, lift the second hammer between the first
and third hammers, which remain at rest.<SPAN style="mso-spacerun: yes">
</SPAN>As the middle hammer rises, it will appear to move away from the hammer
to its right, and closer to the hammer to its left.<SPAN
style="mso-spacerun: yes"> </SPAN>While the hammers are all at rest, the
adjacent faces of the sides of the hammers are parallel.<SPAN
style="mso-spacerun: yes"> </SPAN>You can measure the distance between
the hammers at the crown, at the tip of the molding, or at the widest part of
the felt.<SPAN style="mso-spacerun: yes"> </SPAN>These distances will
all be equal for both pairs of hammers, if all has been done correctly.<SPAN
style="mso-spacerun: yes"> </SPAN>Once you lift the center hammer, thes
e faces are no longer parallel.<SPAN style="mso-spacerun: yes">
</SPAN>With the middle hammer shank held parallel to the keybed the point of
closest proximity between the middle hammer and its neighbors has
changes.<SPAN style="mso-spacerun: yes"> </SPAN>As the hammer rises in
its arc of rotation, any given point on the hammer is moving away from the
keyboard, as well as upward.<SPAN style="mso-spacerun: yes"> </SPAN>The
point of closest proximity between the first and second hammer is the lowest
point of the second hammer’s molding, and a point on the felt of the first
hammer beyond its centerline.<SPAN style="mso-spacerun: yes">
</SPAN>This point beyond the centerline of the first hammer is further to the
right than the centerline of the hammer, due to the angle of its bore.<SPAN
style="mso-spacerun: yes"> </SPAN>Nothing has moved left or right, but
the hammer tail of the second hammer has moved enough away from the keyboard
to place it closer! to the felt of the first hammer angling in its
direction.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">Now, rotate all three
hammers on their shanks very slightly toward the bass.<SPAN
style="mso-spacerun: yes"> </SPAN>Changing only this, you can find an
angle where the distance between hammers are equal, while the middle hammer is
raised between its two neighbors, at rest.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">Tapering the hammer
tails mitigates this condition, but does not entirely eliminate it.<SPAN
style="mso-spacerun: yes"> </SPAN>Over time, with misalignment of hammer
spacing, shank warpage, etc., there is a greater risk of bass hammers rubbing
the hammer to its left, since it is inherently closer to this hammer when the
first is elevated and the neighbor to its left is at rest.<SPAN
style="mso-spacerun: yes"> </SPAN><o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">Recognizing this, many
manufacturers deliberately tilt the bass hammers slightly to the left, and the
tenor hammers slightly to the right.<SPAN style="mso-spacerun: yes">
</SPAN>The degree of this tilt is calculated to precisely correspond to the
angle of the hammer bore.<SPAN style="mso-spacerun: yes"> </SPAN>In
smaller pianos, with greater hammer bore angles, this condition is
exaggerated, and more apparent.<SPAN style="mso-spacerun: yes">
</SPAN>As the tenor hammer bore angle becomes less and less, so does the tilt
to the right.<SPAN style="mso-spacerun: yes"> </SPAN>Once you get high
enough in the treble that there is no bore angle (parallel to the sides of the
hammer), there is, correspondingly, no further tilt to the right.<SPAN
style="mso-spacerun: yes"> </SPAN>This creates another problem.<SPAN
style="mso-spacerun: yes"> </SPA! N>If hammers are tilted in this
fashion on a piano that was not designed for it, the hammer shanks will have
to be moved out of perfect alignment to the whippens in order to center the
hammer under the strings.<SPAN style="mso-spacerun: yes">
</SPAN>However, when the piano has been designed for this left to right tilt,
the action scale is altered to correspond to the exact amount of tilt intended
for the hammers.<SPAN style="mso-spacerun: yes"> </SPAN>You can
determine if this is the case by measuring at the point with the difference is
the greatest.<SPAN style="mso-spacerun: yes"> </SPAN>In the bass, where
the hammers tilt left, the hammer flange screw are shifted to the right,
corresponding the degree of tilt.<SPAN style="mso-spacerun: yes">
</SPAN>In the tenor, where the hammers tilt right, the hammer flange screws
are shifted to the left, corresponding the degree of tilt.<SPAN
style="mso-spacerun: yes"> </SPAN>This makes the spa! ce between
the highest bass flange screw and the lowest tenor flange s crew less that the
corresponding distance at the strike point at the strings.<SPAN
style="mso-spacerun: yes"> </SPAN>If you carefully measure the distance
between the strike points of these two notes at the strings, and find it to be
greater than the distance between the corresponding flange screw, the
foregoing explains why.<SPAN style="mso-spacerun: yes"> </SPAN>If you
propose to replace the hammers on a piano designed in this way, you must tilt
the hammers right to left, as the original hammers were installed in order to
maintain perfect alignment between the shanks and whippens, while maintaining
perfect spacing of the hammers to the strings, and also optimizing the
clearance between hammers as they move between the at-rest position and the
fully elevated position.<SPAN style="mso-spacerun: yes"> </SPAN>If you,
on the other hand, you find the spacing of the strike point at the string to
be identical to the spacing of the flange screws, you can still til! t the
hammers left to right to optimize the clearance of the hammers in motion, but
it will be at the expense of perfect alignment of the shanks to the
whippens.<o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"> <o:p></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">I am sure that this is
difficult to visualize from my feeble attempt to describe it, but demonstrate
it for yourself with the three hammers, as described above.<SPAN
style="mso-spacerun: yes"> </SPAN>You will clearly see it for
yourself.</SPAN></P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'"></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0mm 0mm 0pt"><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'MS Sans Serif'">Frank
Emerson</SPAN></P></DIV></SPAN></DIV></BLOCKQUOTE></BODY></HTML>