<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Re: No Power Yamaha revisited (accurate bedding =
adjust</TITLE>
<META http-equiv=Content-Type content="text/html; =
charset=us-ascii">
<STYLE type=text/css>BLOCKQUOTE {
PADDING-BOTTOM: 0px; PADDING-TOP: 0px
}
DL {
PADDING-BOTTOM: 0px; PADDING-TOP: 0px
}
UL {
PADDING-BOTTOM: 0px; PADDING-TOP: 0px
}
OL {
PADDING-BOTTOM: 0px; PADDING-TOP: 0px
}
LI {
PADDING-BOTTOM: 0px; PADDING-TOP: 0px
}
</STYLE>
<META content="MSHTML 6.00.2800.1126" name=GENERATOR></HEAD>
<BODY>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>Ron,</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>I find
this procedure extremely useful to check the initial bedding and =
particularly on
less flexible frames.</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>Not
all dial gauges can be inserted in all pianos, one may check the length =
of the
plunger (the </FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>cheaper are the less tall) .</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>with
the inverted position, very soon the lower extremity of the gauge is =
touching
the bottom, I have to use the tool with the keys pushed down, the move =
when the
bolt touch the frame is yet visible clearly, but one may be careful not =
to push
too strong on the key (and the frame)</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>The
draw back is that once the piano is in the field(s), you check and move =
the
bolts so often that the initial bedding is less useful soon, I don't =
carry a
dial gauge with me for concert work.</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003></SPAN><SPAN =
class=527504603-24052003><FONT
face=Arial color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>And I
like the idea of working with less tools (while if you see my tools bag =
you may
not believe that ;>)</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>How
about this translation, was it checked for accuracy =
?</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>Best
Regards.</FONT></SPAN></DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=527504603-24052003><FONT face=Arial color=#0000ff =
size=2>Isaac
OLEG</FONT></SPAN></DIV>
<P><FONT size=2></FONT> </P>
<P><FONT size=2>Isaac OLEG<BR><BR>Entretien et réparation de
pianos.<BR><BR>PianoTech<BR>17 rue de Choisy<BR>94400 VITRY sur
SEINE<BR>FRANCE<BR>tel : 033 01 47 18 06 98<BR>fax : 033 01 47 18 06 =
90<BR>cell:
06 60 42 58 77 </FONT></P>
<BLOCKQUOTE dir=ltr
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT =
face=Tahoma
size=2>-----Message d'origine-----<BR><B>De :</B>
pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]<B>De la =
part
de</B> Ron Overs<BR><B>Envoyé :</B> samedi 24 mai 2003
04:43<BR><B>À :</B> Pianotech<BR><B>Objet :</B> Re: =
No Power Yamaha
revisited (accurate bedding adjustment)<BR><BR></FONT></DIV>
<DIV>At 12:26 PM +0200 23/5/03, Richard Brekne wrote:</DIV>
<BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE cite="" type="cite">Yes... this is the proceedure I've =
been
using for nigh on 20 years now. Ever Since Laroy's first visit to =
Oslo. And
as I have said, it generally has worked well, but recently I have =
run into 3
instruments where this was not enough. This proceedure left the =
keyframe
bedded, with all glide bolts in contact with the =
frame...</BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>(?)<BR></DIV>
<BLOCKQUOTE cite="" type="cite"> but there was lots of lost =
power, and
lots of neighbor hammer bobbing on hard blows,</BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>"Bobbing [adjacent] hammers" is a clear indication that not all =
glide
bolts were accurately adjusted.</DIV>
<DIV><BR></DIV>
<DIV>I remember back about 1990 when a Steinway tech visited Sydney =
for a
three day technical workshop. Two grands were to be regulated by a =
small group
of invited technicians.</DIV>
<DIV><BR></DIV>
<DIV>On the first day the usual paper shim under the bolts, lifting =
and
tapping procedure was demonstrated by the Steinway technician, to show =
the
locals just how it was done. I wasn't impressed since we had for some =
years
been using our own dial-indicator procedure (which is accurate and =
quick - a
while back the PTG published one of my documents detailing this =
procedure in
the Journal).</DIV>
<DIV><BR></DIV>
<DIV>On the second day of the seminar I bought in my dial indicator =
and wooden
mounting block, to demonstrate our procedure. Sure enough, the glide =
bolt
adjustment was 'all over the shop'. The visiting tech seemed =
unimpressed with
our alternative procedure. It never ceases to amaze me how many folks =
stick
with an inferior procedure just because its 'the way we've always done =
it'.</DIV>
<DIV><BR></DIV>
<DIV>Anyhow, for those who may be interested in our procedure, I will =
take you
through the process.</DIV>
<DIV><BR></DIV>
<DIV>A dial indicator is mounted in a small wooden block with a single =
hole
sized to create a slight interference fit with the rear plunger cover =
of the
dial indicator (see diagram below).</DIV>
<DIV><BR></DIV>
<DIV align=center><IMG src="cid:527504603@24052003-0bbc"></DIV>
<DIV align=center><BR></DIV>
<DIV>The mounted dial indicator is used to set exactly the adjustment =
of each
glide bolt, so that each just makes contact with the key bed. After =
the
precise contact position has been established, each bolt is =
re-adjusted down a
further small amount to ensure that the key frame doesn't lift the =
glide bolts
clear of the key bed during variable weather conditions.</DIV>
<DIV><BR></DIV>
<DIV>The procedure we use is as follows;</DIV>
<BLOCKQUOTE>
<BLOCKQUOTE><BR></BLOCKQUOTE>
<BLOCKQUOTE>* All glide bolts are adjusted up to clear the key bed =
while
the touch blocks are fitted to the piano and tightened. If an =
action has
mid section glide bolts (eg. Yamaha) you will need to remove a key =
over
each one to enable adjustment access with the action in the piano. =
These
also are initially adjusted to clear the key bed.</BLOCKQUOTE>
<BLOCKQUOTE><BR></BLOCKQUOTE>
<BLOCKQUOTE>* The dial indicator is positioned right next to each =
glide
bolt in turn, with the wooden block resting on top of the balance =
pins
while the dial indicator plunger is depressed by the underside of =
the pin
block (and showing a measurement which is mentally noted). The =
adjacent
glide bolt is adjusted down until the dial indicator moves just 1 =
thou' or
0.025 mm. This procedure is repeated for all glide bolts until all =
are
just contacting the key bed.</BLOCKQUOTE>
<BLOCKQUOTE><BR></BLOCKQUOTE>
<BLOCKQUOTE>* Now repeat the adjustment procedure again, only this =
time
adjust all glide bolts down a further 5 thou' or 0.125 =
mm.</BLOCKQUOTE>
<BLOCKQUOTE><BR></BLOCKQUOTE></BLOCKQUOTE>
<DIV>That's it!</DIV>
<DIV><BR></DIV>
<DIV>The reason behind adjusting the glide bolts to a just-contacting =
setting,
before finally pre-loading the balance rail, is that the initial 1 =
thou' or
0.025 mm adjustment will not cause any positional change of the =
balance rail
which might interfere with the initial setting of the other glide =
bolts. The
end result is absolutely accurate and, provided that the front and =
rear
contact surfaces of the key frame to key bed are accurate, it will be =
quiet
and there will be no 'bobbing' hammers.</DIV>
<DIV><BR></DIV>
<DIV>Dial indicators are generally available at any good engineers =
supply. The
one illustrated above was lifted from the Cutting Tool Mall website =
at;</DIV>
<DIV><BR></DIV>
=
<DIV>http://www.cuttingtoolmall.com/catalog/standard.cfm?FamilyID=90010=
0</DIV>
<DIV><BR></DIV>
<DIV>Cutting Tool Mall is in New York state, they sell on-line, and =
the prices
look OK. Furthermore, when used with a magnetic stand, the dial =
indicator can
be used between the plate and the bridge as the definitive tool for =
adjusting
the set bolts. We set-up our pianos with the set bolts just contacting =
the
plate in its resting position. There are many uses for a dial =
indicator in
piano work.</DIV>
<DIV><BR></DIV>
<DIV>On my return trip from the 2001 Reno convention I called on =
Richard
Davenport and toured his LA workshop. Richard had independently come =
up with
the same idea of using a dial indicator for setting the glide bolts. =
So all
roads do lead to Rome.</DIV>
<DIV><BR></DIV>
<DIV>Best,</DIV>
<DIV>Ron O.</DIV>
<DIV><BR></DIV><X-SIGSEP><PRE>--
</PRE></X-SIGSEP>
<DIV>_______________________<BR><BR>OVERS PIANOS - SYDNEY<BR>Grand =
Piano
Manufacturers<BR><BR>Web:
=
http://overspianos.com.au<BR>mailto:info@overspianos.com.au<BR>__________=
_____________</DIV></BLOCKQUOTE></BODY></HTML>