Killer Octave Question

[Greg Newell]

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John,
         If you would allow me some follow up I'd like to split up your 
post and intersperse some questions for clarity below.


At 10:33 PM 4/12/2003, you wrote:

>Greg,
>
>If the crown was created by being deformed for many years we would see all 
>piano makes with this feature. If this were so they all would have crowned 
>bridges. But clearly some makes have crown and others don't.

Good point! I haven't seen enough of them to make this comparison.

>Maple bridges are quite stiff and I doubt that the crown I see could be 
>caused by the ribs pushing up. There is after all the force pushing down 
>from the string bearing.

Not exactly what I had in mind. My line of thought was more of crown having 
been formed in the maple bridge from simply conforming to a surface the 
bridge was mated to. The ribs wouldn't actually push up since the crown has 
been cut into them, correct? Were these tow manufacturers using rib crowned 
boards in their earlier endeavors?

>I can't say if every single piano from these sources had the same amount 
>of crown to begin with or whether sometimes they would leave it out but I 
>can say with reasonable certainty that practically every one I have 
>removed from a soundboad had at least some crown.

Are you speaking of S & S and Mason and Hamlins here? Earlier, above, you 
intimated that not all bridges you've removed have crown in them.

>It is much more obvious on the larger pianos than the smaller ones. I have 
>taken Model D bridges off that show a full 3/4" or more of crown under the 
>killer octave after fifty years. This same piano probably had 1/8" of 
>crown left on the longest ribs.

Is this even throughout the killer octave area that started this whole 
thread? If so, this seems like some pretty good numbers. Why was the board 
being replaced?


>I will try to get to your other question later. I am tiered from all the 
>back and forth with Ron's postings.

No hurry. I'll look for your post another day. Thanks for the time and 
energy to reply.


Greg


>John Hartman RPT
>
>John Hartman Pianos
[link redacted at request of site owner - Jul 25, 2015]
>Rebuilding Steinway and Mason & Hamlin
>Grand Pianos Since 1979
>
>Piano Technicians Journal
>Journal Illustrator/Contributing Editor

Greg Newell
mailto:gnewell@ameritech.net 

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