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<FONT face=Tahoma size=2><B>From:</B> pianotech-bounces@ptg.org
[mailto:pianotech-bounces@ptg.org] <B>On Behalf Of </B>Roger
Jolly<BR><B>Sent:</B> April 15, 2005 11:34 PM<BR><B>To:</B>
Pianotech<BR><B>Subject:</B> RE: The "Jolly Loop" (Modified by Kent
Swafford)<BR></FONT><BR></DIV>
<DIV></DIV>At 11:34 PM 4/8/2005, you wrote:<BR>
<BLOCKQUOTE class=cite cite="" type="cite"><FONT face="Comic =
Sans MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic =
Sans MS"
color=#000080></FONT><BR><BR>
<DL>
<HR>
<DD><FONT face="Comic Sans MS" color=#000080></FONT>
<DD> I have too much evidence to the
contrary. The end of the knot becomes a theoretical =
termination
point, and the helix is almost incapable of flexing.<FONT
face="Comic Sans MS" color=#000080> =
<BR></FONT><BR></DD></DL><FONT
face="Comic Sans MS" color=#000080>I'd sure like to see it. With =
vertical
hitches the string doesn't have to flex, it pivots at the hitchpin =
itself.
The twist is of no consequence.</FONT></BLOCKQUOTE>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><BR>A
very interesting hypothesis. We may as well stop =
calculating
inharmonicity, on the bare section of core wire, in the speaking =
length. Or is that also of no consequence? Is the =
stiffness
of the swage also of no consequence? <BR>The hitch termination has an =
effect
on the control of bearing and is indeed a great asset in design. =
However
when you double the thickness of the wire over about 50% of the back =
scale
length and mass load it with 3-4 complete turns at the end of the =
knot. It
sure as heck as an effect on the flexibility of the back scale.<SPAN
class=562105607-16042005><FONT face="Comic Sans MS"
color=#000080> </FONT></SPAN></DIV></BLOCKQUOTE>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080>Now, let's not take what I said out of context. This =
issue has
nothing to do with inharmonicity. It has to do with whether or not the =
string is
bending anywhere close to the hitch pin when a vertical hitch pin is =
used. With
the vertical hitch pin arrangement the backscale essentially pivots at =
the
hitchpin. The string is not required to bend up in the twisted portion =
of the
backscale.</FONT></SPAN></DIV>
<DIV dir=ltr><SPAN class=562105607-16042005> </SPAN></DIV>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000080 2px =
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<BLOCKQUOTE class=cite cite="" type="cite">
<DL>
<DD>So many pianos have about a 55mm knot at A0, and only =
about
7-10mm of flexible string. James had a clear demonstration =
model at
the Cal state convention. The reaction of all that saw it =
was wow!
The vibration time of the new knot vs an English loop is about 3 =
times
greater.<BR><BR></DD></DL><FONT face="Comic Sans MS" =
color=#000080>I can see
this if it is compared to a conventional hitchpin system. But not if =
it is
compared to a vertical hitchpin system.</FONT></BLOCKQUOTE>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><BR>It is
the bridge that sets the back scale in motion. Bearing and back =
scale
flexibility interact, and has a profound effect on how the bridge is =
going to
react.. You are trying to say that the stiffness of the =
helix and
mass loading of the knot has no effect on =
flexibility?
Plucking the back scale of the small Walter's grand still sounds =
fairly dead
to me. And that is a fair clue to a stiff back scale.<SPAN
class=562105607-16042005><FONT face="Comic Sans MS"
color=#000080> </FONT></SPAN></DIV></BLOCKQUOTE>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080>I'm aware of this, Roger. I'm the one who has been =
teaching
classes on the curse of the short backscale and the stiffness of the =
twisted
portion of the conventional bass string for the past 25 years, remember? =
So, no,
of course I'm not saying the stiffness of the helix has no effect on the =
flexibility of the wire. But I am saying that it doesn't matter to the =
mobility
of the bridge whether or not there is much of any flexibility in =
the
backscale when vertical hitches are used. This is the whole point of the =
vertical hitchpin.</FONT></SPAN></DIV>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080></FONT></SPAN> </DIV>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080>You points are well taken when you are comparing the =
English loop
(or the German loop -- take your pick) with the standard, or =
conventional,
hitchpin arrangement. But not when they are compared to the vertical =
hitchpin.
With the vertical hitchpin termination something less than the back half =
of the
loop is the only contact point between the string and the back =
termination pin.
The backscale length is not effectively clamped down as it is with the
conventional hitchpin arrangement. Try it for yourself -- take a =
vertical
hitchpin, clamp it in a vice and loop a conventional bass string over =
it. Move
the string up and down and see if the thing has to bend anywhere in the =
twisted
portion of the string.</FONT></SPAN></DIV>
<DIV><SPAN class=562105607-16042005><FONT face="Comic Sans MS"
color=#000080></FONT></SPAN> </DIV>
<DIV><SPAN class=562105607-16042005><FONT face="Comic Sans MS" =
color=#000080>I'm
not trying to diminish the effectiveness of the English loop in any way. =
I'm
just trying to correct what I see as a mistaken perception of how the =
vertical
hitchpin system functions. I still see it as the preferable of the three =
different systems.</FONT></SPAN></DIV>
<DIV dir=ltr><FONT face="Comic Sans MS" color=#000080></FONT><FONT =
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><FONT face="Comic Sans MS" =
color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><BR> </DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000080 2px =
solid; MARGIN-RIGHT: 0px">
<BLOCKQUOTE class=cite cite="" type="cite">
<DL>
<DD>To the previous writer, it is not Del's hitch pins. But =
was
developed and patented by Harold Conklin of the Baldwin piano
company.<FONT face="Comic Sans MS" color=#000080>
<BR></FONT><BR></DD></DL><FONT face="Comic Sans MS" =
color=#000080>The
vertical hitch pin that I most often use is some different than that =
used by
Baldwin. It is this difference the writer was referring to not the =
invention
of the system.<BR></FONT> <BR><FONT face="Comic Sans MS"
color=#000080>And, for what it's worth (and with respect to Mr =
Conklin's
many other achievements), when I was at Baldwin I was told by both =
Bob
Cutshall (then head of engineering) and Bob Farris (then chief piano =
engineer) that the actual inventor of the vertical hitch and the =
floating
plate mounting system was a piano technician/rebuilder who worked in =
the
R&D shop.</FONT></BLOCKQUOTE>
<DIV><FONT face="Comic Sans MS" color=#000080></FONT><FONT
face="Comic Sans MS" color=#000080></FONT><FONT face="Comic Sans =
MS"
color=#000080></FONT><BR>I was lead to believe the patent reads H. =
Conklin and
the Baldwin Piano Company. I guess I am corrected?<SPAN
class=562105607-16042005><FONT face="Comic Sans MS"
color=#000080> </FONT></SPAN></DIV></BLOCKQUOTE>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080>Baldwin's name is there as the patent owner by virtue of =
assignment. As I recall there are other names on the patent as well. I'd =
have to
do a search for the number and look it up (it's a pre-1976 =
patent). As
may be, I'm just passing on what I was told by folks who were there at =
the
time.</FONT></SPAN></DIV>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080></FONT></SPAN> </DIV>
<DIV dir=ltr><SPAN class=562105607-16042005><FONT face="Comic Sans =
MS"
color=#000080>Del</FONT></SPAN></DIV></BODY></HTML>