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<DIV><FONT face="Times New Roman">At 08:48 26/09/01 +1000, Overs =
Pianos
wrote:</FONT></DIV>
<DIV><BR><FONT face="Times New Roman"><FONT color=#008080>Is this =
the action.
Thanks for sending this to the list Clarke.<BR></FONT><BR>I did say, in =
the
message you quote, that this is of course NOT the action.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">This is the one:</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman"><IMG alt="" hspace=0
src="cid:001d01c1468d$4fffecf0$0100007f@eremita" align=baseline
border=0></FONT></DIV>
<DIV><FONT face="Times New Roman"><BR></FONT></DIV>
<DIV dir=ltr style="MARGIN-RIGHT: 0px"><FONT face="Times New =
Roman"
color=#808080> &nb=
sp;
J<BR><BR> L =
R
C<BR> &n=
bsp;
H<BR><BR>In the Herrburger lever JL is 70, LC is 69, LR is 9.5 and R is =
almost
in line with LC.</FONT></DIV>
<DIV dir=ltr style="MARGIN-RIGHT: 0px"><FONT face="Times New =
Roman"
color=#808080>JC is 50. LH is 47, CH is 30. The jack =
tender makes
contact 26 mm from C, 4 mm</FONT></DIV>
<DIV dir=ltr style="MARGIN-RIGHT: 0px"><FONT face="Times New =
Roman"
color=#808080>above the line LC produced.</FONT></DIV>
<DIV class=cite type="cite" cite><BR><FONT face="Times New Roman"
color=#008080>John, would you mind explaining the letter diagram you =
have used
above, just to avoid confusion. Thanks.<BR></FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman">J =
= Jack corner
(=knife cut on rep lever)</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman">L =
= Intermediate
lever centre</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman">R =
= Repetition
lever centre</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman">C =
= Jack
centre</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman">H =
= Mid-point of
lever heel<BR></FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman"
color=#808080>supposing it is 8, then reducing LC to 75, as you have =
done, will
diminish this</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Times New Roman"
color=#808080>figure and reducing it to 69 as Herrburger did will =
diminish it
further</FONT></DIV>
<DIV class=cite type="cite" cite><FONT face="Frutiger =
Linotype"></FONT><BR><FONT
face="Times New Roman" color=#008080>How?</FONT></DIV>
<DIV><FONT face="Times New Roman" color=#008080></FONT> </DIV>
<DIV><FONT color=#008080><FONT face="Times New Roman" =
color=#000000>You wrote
<FONT color=#008080>"...the roller/knuckle contact scrubs badly since =
the
contact is around 8 mm below the line of centers at the rest
position."<BR></FONT></FONT></FONT></DIV>
<DIV><FONT face="Times New Roman">Have I not understood you? You =
are
talking of the line from hammer centre to lever centre I =
understood. If we
take a <STRONG>hypothetical </STRONG>set-up with a 50 mm jack at a given =
angle,
a horizontal line from lever centre to jack centre (whether 99 or 75 or =
69)
and a given vertical distance from this line to the hammer centre, =
and a
line AB from hammer centre to lever centre, then</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">a) the closer the lever centre =
approaches to
the jack centre, the shorter the distance of the contact point below the =
line
AB.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">b) the smaller the roller , the =
shorter the
distance of the contact point below the line AB.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">That's all I'm saying.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">In practice the line from lever =
centre to jack
centre at rest is rarely horizontal.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">What I am saying is that you have =
reduced the
length of this line to 75 and Herrburger reduced it to 69; both you and
Herrburger use the older 9 mm roller rather than the current 10 mm =
roller and
there are good reasons for these choices. I have not yet =
investigated the
geometry of your action and it's probably 20 years since I investigated =
the
Herrburger action, but there is no doubt that either is preferable to =
any
currently used version of the Erard-Herz action. I do doubt though =
whether
your version is significantly better than Herrburger's if at all. =
When I
have time, I'd like to make drawings to make a proper =
comparison.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">I have a question about your angled =
lever
heel/capstan block, which looks that same as an arrangement patented by =
Grotrian
in 1905. I see no rationale for this and Pfeiffer says of it =
"..the point
of view on which the patent was based is not to be upheld." It =
looks to me
also as if this arrangement makes even more fiddly the process of =
adjusting the
capstan screw.</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman">JD</FONT></DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman"></FONT> </DIV>
<DIV><FONT face="Times New Roman"></FONT><FONT
face="Times New Roman"></FONT> </DIV></BODY></HTML>