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<font size=3>Can you further describe the 'thud'. Only on fff,
right or on p ? Teflon in whippens?<br>
<br>
Heaven forbid that the plate is touching (barely) the back of the bridge
in the top section.<br>
<br>
I didn't see that you checked the height of the shift lever above the
keybed and the height<br>
of the notch in which it resides.<br>
<br>
!!!!!!!!!! Front rail pin too high? :-0<br>
<x-tab> </x-tab>I've had
that happen.<br>
<br>
Balance rail pin hitting wood, loose back checks. Does it happen
with the dampers lifted?<br>
<br>
Worn damper upstop felt (hitting rail). Hardened key end lifter
felt (damper lifter).<br>
<br>
...grasping at straws...<br>
<br>
Jon Page<br>
<br>
At 08:26 PM 12/02/2000 -0500, you wrote:<br>
<blockquote type=cite cite>Remember THUD?<br>
Here is the history. I had not seen this piano until last
month.<br>
While tuning I noticed that notes 50, 51, 52, and 53 (top four notes
in<br>
agraff section, just below the treble break) had an
unpleasant<br>
knock/slap sound, the same percussive knock which is in the background
of<br>
all piano tone, but in notes 50-53 it dominates the tone. These are
the<br>
four notes between A440 and the treble break. The orchestra
conductor<br>
asked me if I had noticed those four notes, as did the pianist, so I
knew<br>
it wasn't just my imagination. I have checked it out both upstage and
back<br>
stage (wood floors), and back at the dealership (concrete floor).<br>
Here is what we have done so
far:<br>
1. checked hammers for loose glue joint, flange pinning, and
screw<br>
tightness,<br>
2. visually checked the action frame joints between notes #53 &
#54,<br>
3. checked the wippens for sufficient felt at the front to keep
the<br>
jack from slamming into the rep lever,<br>
4. checked key frame bedding, front, back, and glides, with and
without<br>
damper pedal, and with and without shift pedal,<br>
5. pressed down the back key frame with a long screwdriver to see
if it<br>
was slapping up against the dag,<br>
6. played notes with dampers held all the way up by hand and by
pedal,<br>
7. moved the action in and out to see if the tone improved,<br>
8. switched some hammers from the octave below to see if it could
be the<br>
hammers,<br>
9. switched some whippins from the octave below to see if it coulb
be the<br>
whippins,<br>
10. seated the strings,<br>
11. applied firm pressure on the bridge cap at the end of the
section to<br>
see if there was a loose glue joint between cap and bridge body,<br>
12. checked for clearance between the bridge and the plate,<br>
13. checked for loose ribs,<br>
14. checked for clearance between nose and bell bolts and
soundboard,<br>
15. checked that the bell bolt nut which was one turn past finger
tight,<br>
16. checked for foreign object lodged between soundboard and frame,
and<br>
between soundboard and plate,<br>
17. tightened the end screws of the diagonal plate bar, which could
be<br>
turned another half turn to snug,<br>
18. checked key leads and underlever leads,<br>
19. checked the key bed with a straightedge front to back. I
found that<br>
the board just beyond the board on which the balance rail glides rest
was<br>
high. Chalked it where it passes under the front to back board of
the key<br>
frame which is just under notes 50-53 and found that is was just
barely<br>
touching. Sanded key frame there until there was adequate
clearance.<br>
Playing the note by pushing up on the whippin from underneath with my
<br>
finger without moving the key still produces the THUD, so I guess that
<br>
eliminates the keyframe anyway. <br>
<br>
None of this has changed the THUD. <br>
What have I missed? <br>
Why these four consecutive notes with no sign of the problem above
or<br>
below them? <br>
<br>
John Chapman RPT<br>
Wake Forest University<br>
Winston-Salem NC</font></blockquote><br>
<div>Jon Page, piano technician</div>
<div>Harwich Port, Cape Cod, Mass.</div>
<div><a href="mailto:jonpage@mediaone.net" EUDORA=AUTOURL>mailto:jonpage@mediaone.net</a></div>
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