Rock Maple Hammer Cores

[antares]

Thank you very much Del! That was a very clear answer, along with the 
other generous answers we got through this list.
Pretty soon we will inform you of a new hammer which does not exist 
yet, and which might be of value for all.

Friendly greetings,

André Oorebeek


On 12-feb-04, at 20:18, Delwin D Fandrich wrote:

>
>
>> -----Original Message-----
>> From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On
>> Behalf Of Phillip Ford
>> Sent: February 11, 2004 1:03 PM
>> To: pianotech@ptg.org
>> Subject: Re: Rock Maple Hammer Cores
>>
>>
>> Andre O wrote:
>>>
>>> I have nothing against maple for many uses in piano manufacture, but 
>>> I
>>> believe there are more suitable woods for hammer cores.
>>> ...
>>> My early experience with Hornbeam cored Imadagawa hammers put me off
> using
>>> hard core wood for hammer cores. You could voice these things 
>>> forever and
>>> they still screamed at you, similar to the early series Kawai KG 
>>> hammers.
>>> I understand that hammer manufacturers have to be very careful when
>>> pressing up hammers made with lighter cores such as Walnut or 
>>> Mahogany. I
>>> suspect that when using maple (or hornbeam) cores, it is possible to 
>>> load
>>> them up to the max. in the press without fear of damaging the 
>>> core-wood.
>>> Furthermore, you can imagine how much compressional pressure there 
>>> must
> be
>>> right at the apex of the core. A softer core wood provides for a 
>>> level
>>> of 'give' under the highly compressed hammer felt. This may go some 
>>> way
>>> towards explaining why hammers with maple or hornbeam cores are 
>>> generally
>>> so bright.
>>>
>>> Ron O.
>>> --
>>
>> Some time ago I saw a Bluthner piano with hammers having softwood 
>> cores
> (it
>> appeared to be some sort of pine).  Also the nose of the core was not 
>> a
>> sharp point, as is typical now, but a blunt rounded end.  The piano 
>> had a
>> beautiful tone.  I assumed that the reason we do not see softwood 
>> cores
>> these days was because of strength issues when pressing the hammers.
> Would
>> there be other reasons?  Also, what's the point of the point on the 
>> nose
> of
>> the core?  Is it tonal, or is it to help in keeping the felt from 
>> moving
>> around when the hammers are pressed (or some other reason)?
>>
>> Phil Ford
>> ----------
>
>
>
> I've been hearing about the tonal characteristics of the various 
> species of
> wood used for hammer moldings for something over four decades now. And,
> still, I remain unconvinced.
>
> Molding wood is chosen for a variety of reasons, mass being only one of
> them. And that is a very minor consideration, indeed. If you actually 
> weigh
> hammer moldings of approximately equal strength and stiffness -- 
> especially
> once they are all tapered, coved, curved, etc. -- you'll find that the 
> any
> mass differences are so slight as to be virtually non-existent.
>
> One of the most significant factors in this choice is how much 
> compression
> and shear stress the wood (obviously, with the grain) can bear without
> bending and/or breaking. Denser and thicker hammer felt requires higher
> press pressures and stronger and tougher wood moldings must be used. 
> Hence,
> in hammers like (but certainly not limited to) the very hard 
> Imadagawa's --
> which use a lot of dense felt and relatively high press heat and 
> pressure --
> we see molding woods like hornbeam or maple being used. (Hammer press
> alignment and the skill of the press operator can also be factors -- a 
> press
> in poor alignment places more shear stress on the molding as does a
> misaligned felt strip.
>
> It would be nice to be able to make a general rule about this: maple 
> molding
> = dense and heavy hard-pressed hammers; walnut or mahogany moldings =
> lighter, softer and more resilient hammers. Unfortunately, such
> generalizations are not accurate, even though we often see them. One 
> hammer
> maker might use the great strength of maple to make a slender, 
> beautifully
> tapered hammer molding that is both stronger and less massive than 
> another's
> thick and chunky mahogany molding. If the felt pressed on these maple
> moldings is of reasonable density and texture and is pressed using
> reasonable temperatures and pressures the resulting hammers will 
> outperform
> those chunky mahogany hammers in all respects. Personally, I like maple
> moldings because the seem to hold a good backcheck surface longer and 
> they
> It's all a balancing act.
>
> Blaming the species of wood used in the hammer molding for the mass, 
> density
> and character of the felt is a bit like blaming the horse for the
> uncomfortable saddle. Dense, hard-pressed hammers get that way because 
> of
> the characteristics of the felt coupled with the heat and pressure of 
> the
> press, not because of the species of wood used in the moldings. Woods 
> like
> hornbeam or maple are required in these hammers only because they are 
> strong
> enough to stand up to the physical abuse the moldings are subjected to
> during the press cycle. They have little or nothing to do with the 
> aural
> abuse we are subjected to by the hammers made this way.
>
> Del
>
>
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>
>
friendly greetings
from
André Oorebeek

Amsterdam -
The Netherlands

0031-20-6237357
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