Hi Doug,
Just wanted to encourage you on your project. You are in the trenches of
design and your findings will enlighten us all. No substitute for trial
and error. Go Forward!
James Grebe
R.P.T. of the P.T.G.
St. Louis, MO.
Competent Service since 1962
Caster Cup Center of the Universe
Home of Handsome Hardwood Caster Cups
pianoman@inlink.com
----------
> From: Doug Richards <Doug.Richards@quantum.com>
> To: pianotech@ptg.org
> Subject: RE: Single Treble Bridge
> Date: Saturday, August 29, 1998 4:07 PM
>
> Jon,
> Thanks for the offer on the wall sculpture, ah, I mean piano. I even
have a
> corner of my "shop" (garage) to put it! :-)
>
> Seriously (or maybe you were)
>
> What I was after was a soundboard outline to continue the string model.
At
> this point, I'm just following an idea and don't want to take the time to
> measure. If the results look like something I believe or come up with
an
> idea on an improvement, I'll model parts from a real piano that I could
take
> measurements from, create a FEA model, make 'theoretical' improvements on
> the piano, then check out the 'real' improvements. Before I spend too
much
> money, I thought I'd take the time to go through a complete analysis to
find
> out how much effort it takes and if any new modeling ideas come up that
I'd
> really want to test on a real piano.
>
> doug richards
> San Jose, CA
>
> > -----Original Message-----
> > From: Jon Page [SMTP:jpage@capecod.net]
> > Sent: Saturday, August 29, 1998 5:28 AM
> > To: pianotech@ptg.org
> > Subject: RE: Single Treble Bridge
> >
> > Doug,
> > I have just the item for you.
> > A Rippen back w/ Aluminium plate, board/bridges, strung. 40"h
> >
> > Having given the fold-down action/keyboard to Debbie Legg,
> > the back NEEDS a place to go. PERFECT for the your project.
> >
> > Only thing, it's here on the East Coast. I can prep it for shipping
> > and get it to the freight dock, (we'll pass the plate for shipping
> > for everyone to reap the benefits of your samplings. :-)
> > It's a light-wieght compared to most, this piano was designed
> > to be portable hence the fold-down keyboard.
> > Full perimiter plate, no back posts, just plate, board, strings.
> > The block is segmented like the Yamaha elec. grands.
> >
> > I can pack it up this week and send it on it's way since I have to go
to
> > that same freight dock to pickup a piano coming in for refinishing.
> >
> > I can call for a rough price on shipping on Monday.
> >
> > Don't miss this opportunity to gain a valuable testing device
> > and clear-up a corner of my shop !
> >
> > Anxiously awaiting your reply,
> >
> > Jon Page
> > Harwich Port, Cape Cod, Mass. (jpage@capecod.net)
> >
> > PS Makes a nice wall sculpture too.
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > At 12:52 PM 8/28/98 -0700, you wrote:
> > >Del,
> > >
> > >You wouldn't happen to have an outline of a medium sized sound board
and
> > >bridge in electronic format would you?
> > >Don't know if you saw my post yesterday, but I'm doing some modeling
on
> > >string inharmonicity. Some time in the future, I'll be wanting to add
a
> > >soundboard with bridge and look at string tail length/angle,
soundboard
> > mode
> > >shapes and stuff like that.
> > >Anyway, if you have a file available (dwg, mi or dxf) it sure would
save
> > me
> > >a bunch time measuring...
> > >
> > >doug richards
> > >San Jose, CA
> > >
> > >> -----Original Message-----
> > >> From: Delwin D Fandrich [SMTP:pianobuilders@olynet.com]
> > >> Sent: Friday, August 28, 1998 10:47 AM
> > >> To: pianotech@ptg.org
> > >> Subject: Re: Single Treble Bridge
> > >>
> > >>
> > >>
> > >> Tom Cole wrote:
> > >>
> > >> > Del,
> > >> >
> > >> > You discussed, in a recent post, the need for a separate tenor
bridge
> > >> > for wound strings and that the speaking lengths should be an
> > extension
> > >> > of the bass section. It occurred to me today that Steinway tried
that
> > >> > over 100 years ago and abandoned the idea. I also have heard of
> > someone
> > >> > who has converted the early model As to a single treble bridge
> > design,
> > >> > saying that it's an improvement.
> > >> >
> > >> > So I'm confused and would like to hear your opinions on this
> > conundrum.
> > >> >
> > >> > Tom
> > >>
> > >> --------------------------------------------------
> > >>
> > >> Tom,
> > >>
> > >> Over the years Steinway has abandoned a lot of good design ideas
while
> > >> clinging
> > >> tenaciously to a few bad ones. Obviously, Steinway builds some
> > excellent
> > >> pianos, but they are certainly not the last word in piano design.
Nor
> > am
> > >> I.
> > >> Nor is anyone else that I know of. So, with that in mind...
> > >>
> > >> Not all of the ideas that were tried out and abandoned 100 years ago
--
> > >> whether
> > >> by Steinway or by anyone else -- were bad ideas. Sometimes ideas
came
> > >> along
> > >> before their time and had to wait for appropriate materials to come
> > along.
> > >> Sometimes manufacturing technology was not developed adequately to
take
> > >> full
> > >> advantage of an idea. Other times a good idea was simply executed
> > poorly.
> > >> This
> > >> was the case with the short bridge on the three-bridge Model A. I'm
> > >> assuming
> > >> this is the piano you're referring to in your post.
> > >>
> > >> There were three problems with this specific design:
> > >> 1) The string lengths in the short bridge section were too
short.
> > I
> > >> assume
> > >> this was done so that tri-chord wrapped strings could be used.
This,
> > of
> > >> course,
> > >> was the second problem.
> > >> 2) Tri-chord wrapped strings were used. I have yet to see a
scale
> > >> using
> > >> tri-chord wrapped strings that I really liked.
> > >> 3) The soundboard and ribs did not acoustically tie the three
> > >> separate
> > >> sections together. In part this was a consequence of the
> > >> compression-crowned
> > >> soundboard design. It is very difficult -- nearly impossible -- to
> > alter
> > >> the
> > >> elasticity characteristics of a compression-crowned soundboard to
> > >> adequately
> > >> blend the several disparate sections of the scale together.
> > >>
> > >> There are some real problems trying to redesign things like this on
an
> > >> existing
> > >> piano. I am also interested in loudspeaker design. The bass/tenor
> > >> transition
> > >> of the piano scale is much like the crossover design between a
woofer
> > and
> > >> a
> > >> mid-range speaker -- fairly simple in concept, much more difficult
in
> > >> actual
> > >> practice. We struggle with these issues every day since nearly
every
> > >> piano that
> > >> comes to our shop is sent here for some level of redesign along with
> > its
> > >> remanufacture. We are limited by the original string scale layout
--
> > >> i.e.,
> > >> action center spacing and their sweep -- and the original
configuration
> > of
> > >> the
> > >> plate.
> > >>
> > >> In the case of the three-bridge Model A, the compass of the bass
> > section
> > >> should
> > >> have been much greater. In a piano of this size the bass section
> > should
> > >> encompass at least 27 notes (instead of 20). The short tri-chord
steel
> > >> strings
> > >> often found at the low end of the tenor bridge have a tubby tone
that
> > >> simply
> > >> cannot be voiced out with hammer work. Even then there should have
> > been a
> > >> few
> > >> unisons of wrapped bi-chords terminated on a separate bridge on the
> > tenor
> > >> side
> > >> of the bass/tenor plate break. Done properly, this short bridge
could
> > --
> > >> and
> > >> probably should -- have been tied into the long tenor bridge.
> > >>
> > >> I have also worked with the idea of a single treble bridge on these
> > >> scales, but
> > >> I'd not go so far as to call them much of an improvement. They
were,
> > >> perhaps,
> > >> less bad. The real improvement comes with a new short bridge using
> > >> properly
> > >> scaled bi-chord wrapped strings. Along with a soundboard and rib
> > system
> > >> designed to bring the three separate sections -- the low end of the
> > long
> > >> tenor
> > >> bridge, the short cross-over bridge and the high end of the bass
bridge
> > --
> > >> together. Even then, there remains a serious discontinuity between
the
> > >> lengths
> > >> of the low tenor strings and the upper bass strings that cannot be
> > >> corrected
> > >> without building a new plate.
> > >>
> > >> It is really much easier to start with a clean computer screen and
> > design
> > >> the
> > >> thing from scratch. When doing this all of the various factors can
be
> > >> balanced
> > >> out much more easily. Much has been learned about piano design in
the
> > >> past 100
> > >> years. It's just that little of this knowledge has been
incorporated
> > into
> > >> the
> > >> pianos of today.
> > >>
> > >> Rather than answer your question, I've probably just posed a bunch
of
> > new
> > >> ones.
> > >> Such is life. Isn't it wonderful?
> > >>
> > >> Regards,
> > >>
> > >> Del
> > >>
> > >> "If it ain't broke -- break it. Then build it better."
> > >
> > >
This PTG archive page provided courtesy of Moy Piano Service, LLC