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Yes, I've read all that as well. Just one more example of the numbers
alone not telling the whole story. Some years back I compared maple
hammershanks to hornbeam shanks directly, although the tests were not exhaustive.
On average, the maple shanks had less bend to them. I did not find
that the hornbeam shanks "transmitted energy" any better than did maple
shanks -- if as well. The repetition lever stop screw (sometimes
incorrectly called the "hammer drop" screw) became loose in the flange
much more quickly in the hornbeam than in the maple. Hornbeam forks
(where the centerpin goes through) was also more susceptible to impact
damage. The maple shanks were simply "tougher."
<P>There was a greater variation among the maple shanks, however.
In fact, I suspected that some of the maple shanks I tested were actually
made of soft maple, not hard maple as specified. The manufacturer
of the maple shanks was not generally noted for its careful quality control
procedures.
<P>Del
<P>-------------------------------
<P>Frank Weston wrote:
<BLOCKQUOTE TYPE=CITE> <FONT SIZE=-1><FONT COLOR="#000000">I'm coming
in late on this discussion, so maybe someone has already provided this
information which i</FONT>s taken from a Renner brochure included with
my latest order of action parts:</FONT> <FONT COLOR="#000000"><FONT SIZE=-1>BEGIN
QUOTE</FONT></FONT><FONT SIZE=-1>"Renner has found Hornbeam to have significant
advantages because it is more dense in structure, and scores measurably
higher in bending strength and hardness tests over Maple. <B>While
we will manufacture to each customer's own specifications</B>, we recommend
Hornbeam, and Renner USA uses Hornbeam exclusively for the following reasons:</FONT> <FONT SIZE=-1>The
enormous bending strength of Hornbeam -- <B>about 32% higher than Maple
</B>-- has a particular advantage for hammershanks. There is less
warping or back springing when the hammer attacks. This means a better
energy transmission of the hammerhead when attacking the string.
The greater bending strength of Hornbeam also reduces the sliding and rubbing
movement of the hammerhead against the strings when the shank is under
tremendous torque during the attack - the benefit of which is a decreased
wear and tear of the hammerhead felt. Another important benefit of
the increased bending strength is less re-traveling of the hammers.</FONT> <FONT SIZE=-1>The
use of Hornbeam, with our special bushing felt, are important factors in
producing the superior bushing centers in Renner action parts. The
grain direction of the much denser Hornbeam is chosen is such a way that
the flange bushing centers have an optimum position towards this direction.
this guarantees an enormous strength in the section of the two bearings
within the flange, as the center will have a better fit when it is pressed
directly into the wood in this direction (e. g. for whippens, underlevers,
etc..). Also, the pressure put on the center can be increased by
23% when using Hornbeam, instead of Maple before it will remove within
the wooden part."</FONT><FONT SIZE=-1>END OF QUOTE</FONT> <FONT SIZE=-1>Although
a lot of the terminology is incorrect in the strictest sense, and the translation
from German is confusing, a few points come through clearly:</FONT> <FONT SIZE=-1>1.
Renner claims to use Hornbeam because it is a structurally superior wood
to Maple, according to them 33% greater tensile strength, 3.5% greater
Brinell hardness, and 32% greater bending strength.</FONT> <FONT SIZE=-1>2.
Renner implies they will manufacture using what ever wood a customer requests.
They don't say how small an order they will take or how long the delay.</FONT> <FONT SIZE=-1>Frank
Weston</FONT>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: 5px"><B><FONT FACE="Arial"><FONT SIZE=-1>-----Original
Message-----</FONT></FONT></B>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>From: </B>Delwin D Fandrich <<A HREF="mailto:pianobuilders@olynet.com">pianobuilders@olynet.com</A>></FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>To: </B><A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
<<A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>></FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>Date: </B>Sunday, June 06, 1999
2:13 PM</FONT></FONT>
<BR><FONT FACE="Arial"><FONT SIZE=-1><B>Subject: </B>Re: Hornbeam</FONT></FONT>
<P>dporritt wrote:
<BLOCKQUOTE TYPE = CITE> <SPAN class=810422816-06061999><FONT COLOR="#0000FF"><FONT SIZE=-1><FONT FACE="Arial">Del
Fandrich writes:</SPAN><SPAN
class=810422816-06061999></SPAN></FONT>And
who -- besides Renner, that is -- really believes that hornbeam shanks
are<SPAN class=810422816-06061999><FONT FACE="Arial"> </SPAN></FONT>superior
to even relatively decent maple shanks?</FONT></FONT>
<P><FONT COLOR="#0000FF"><FONT SIZE=-1>Regards,</FONT></FONT>
<P><FONT SIZE=-1><FONT COLOR="#0000FF">Del<SPAN
class=810422816-06061999></FONT><FONT FACE="Arial"><FONT COLOR="#000000">I
don't know as much as I'd like to about the relative strengths and weakness
of Hornbeam and Maple. However, I really like the Renner shanks,
bushings, center pin accuracy, friction consistency, shank shape, treble
tapering, phone curtesy, order turn-around time, pleasant dealings.......
that I get from Renner. I suppose they could make good Maple ones
too.</SPAN><SPAN
class=810422816-06061999></SPAN><SPAN class=810422816-06061999>dave</SPAN></FONT></FONT>_______________________________________________</FONT></BLOCKQUOTE>
Dave,
<P>Sorry. I think you misunderstood. I was referring only to
the actual material used, i.e., hornbeam as opposed to maple. As
for the rest, I'll agree with everything you've said except perhaps for
the friction consistency.
<P>And I do wish they made maple shanks. Perhaps even offering us
a choice between the two.
<P>Regards,
<P>Del</BLOCKQUOTE>
</BLOCKQUOTE>
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