>
> It is interesting that several other S's from this era exhibit the
> same problem in the same strut.
A very good indication of a design fault, I'd say.
> The question though is what is it
> about the design of this model that is faulty, assuming that is the
> case.
I don't know. I've never had an S apart, and likely wouldn't know
precisely even if I had. An FEA run would be interesting, to see where
the stresses are if enough accurate measurements could be made.
> The string tensions and break points are high. See attached
> photo. A speaking length of 59 mm at C8 is 93 pounds tension, 280
> pounds unison tension, and a ridiculous break %. Pretty long. Maybe
> time to move the bridge to get the string length down to the 52-54 mm
> range.
If you intend to be able to pull the top half octave to pitch, moving
the bridge is a very good plan. In doing this, you'll also reduce the
overall tensions, and give the plate repair a better chance of long term
success. Moving the entire bridge 6mm forward to a 53mm C-8, you'll
decrease overall tension by over 1,000lbs. But then that's enough work
to consider a board redesign and replacement. Alternately, scab the
front of the bridge in the top section, trim the rear, and recap the
section. It would be less work and damage than moving the entire bridge
on the old board. It also gets the bridge footprint closer to the belly
bar, which might be why it was put that far back in the first place, as
an attempt to de-dink the compression crowned soundboard treble. Just
try to keep the front footprint directly below the front pin row so you
don't build in a cantilever with it's accompanying torque feature. Less
desirable than redesign, but quicker, cheaper, and easier.
Through the years, the Pianotek list(s) have gotten maybe a dozen posts
asking how to get a restrung S&S S up to pitch in the treble without
breaking strings. Unless higher tensile strength wire is available than
we use in stringing pianos, shortening speaking lengths is the only
answer, however accomplished.
> Should I add a brace in that area between rim and belly rail as well
> as plate work to remedy the issue? It would stiffen the belly rail,
> but would it help give structural support?
I've been thinking that very thing. The easiest approach there is with a
socket head bolt in the belly bar, a corresponding socket cut in the
plate, and a spacer/brace between the two. Samick does this in some of
their pianos, and some years back, Ron Overs sent me a couple of the
bolts he made and uses for the retrofit in his rebuilds, with a
recommendation to try them. I used them in a Knabe player grand that had
most of the belly bar cut away for a tubing pathway, and it worked
beautifully to brace the belly bar. The photo is of the trial fit. The
finished bar was better looking, but I still didn't get it aligned very
well, as I didn't have a small right angle drill at the time to do it. I
do now, but it's still an eyeball thing. As for bracing the plate, who
knows, but it couldn't hoit, and the belly bar most certainly could
stand bracing, so it's worth doing in any case.
> Interesting problem.
It is that, and doable. Keep us posted, please. I could use an
interesting project, even as a bystander.
Ron N
Original Message------
Thanks for the replies. I will be talking to a few more people who responded off list but at this point it seems likely that I will be destringing this puppy sooner rather than later. Then I will find a good welder and go the reinforcement/welding route.
It is interesting that several other S's from this era exhibit the same problem in the same strut. The question though is what is it about the design of this model that is faulty, assuming that is the case. The string tensions and break points are high. See attached photo. A speaking length of 59 mm at C8 is 93 pounds tension, 280 pounds unison tension, and a ridiculous break %. Pretty long. Maybe time to move the bridge to get the string length down to the 52-54 mm range.
Should I add a brace in that area between rim and belly rail as well as plate work to remedy the issue? It would stiffen the belly rail, but would it help give structural support?
Interesting problem.
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Alan McCoy
Spokane WA
ahm2352@gmail.com
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Original Message:
Sent: 04-15-2015 14:10
From: Joyce Meekins
Subject: plate crack
Ron -
I'd be interested in your or anyone else's opinion about why three Model S Steinways between 1946-47 would have the same pattern of cracks in plates. I have never had this issue with any other Steinway, and wonder if it's an issue with casting or installation, and why does it take 60 years or more for it to break? Your thoughts?
Would you attempt to reinforce or weld, then continue to use such a plate?
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Joyce Meekins
Greenbelt MD
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