Steinway plate holes

[rwbrpt@juno.com]

To Ron N. , Don P. and list,
The danger in short answers to long questions is here apparent!
I recognize that without a first hand knowledge of piano plate mfg., it
is difficult to visualize the subject via E-mail. However, in the spirit
of my past PTG classes on plates, as well as all of your obvious
questions - I  will go forward.
The "counter sinks" that we see in the majority of pianos are not the
result of secondary operations or machine work. They are the result of
cast in "spots" or "dimples" that are cone shaped and located by the
design and pattern maker to reduce the amount of metal to be drilled and
to provide an auto centering device for the driller. Visualize a cone
shaped recess that is drilled thru with a bit that is smaller than its
outside diameter. The result is a "counter sink" with a hole - but far
less material is cast, drilled or wasted as swarf (shavings). Pretty
important when foundries in the past ran 500 or more plates a day with
220 or more  pin holes in each!
Obviously, the pattern "dimples" reduce the amount of metal poured into
the plate to begin with and this is where the strength factor comes in.
Where holes are closely spaced, the angle of the correct drill lead
"dimple" would cause overlap as well. The Steinway & Sons patterns that
experienced breakage thru these sections (commonly the "A-1" and "B")
were effectively strengthened by eliminating the "large" "spots" in these
center areas and drilling on "small" spots that almost disappear in the
drilling process (just the smallest "edge break" remains to avoid a
secondary operation - at least when all is running well!).
For sure, the subject of "spot " drilling versus modern CNC methods is a
long and interesting. However, I feel that the question of the variation
in the long standing Steinway scales that have sponsored the recent
questions here are best addressed by saying that strength issues as well
as design space requirements will best furnish the answers. Tradition in
this case would be a very minimal consideration.
As in all piano design and mfg., variations are endless and the solutions
to problems - both short and long range -  are so complex and interesting
that these discussions will undoubtedly continue long into the future.
This explanation is deliberately brief, as the subject is complicated by
many factors, however, I hope that this short comment will help clarify
rather than confuse the issue, and I will comment further if you wish.

Bob Beck                
On Sun, 18 Feb 2001 02:01:28 -0700 "dcp2" <dcp2@rmi.net> writes:
> Bob  -  I can buy not doing countersinks if the pins are so close 
> they would
> overlap (now I'll have to go back & look to see if the bass pins are 
> that
> close).  And that would leave some additional material for strength 
> I guess.
> But why go to the expense of removing material from the plate by 
> doing a
> countersink on the rest of the plate from G#3 upward?
> 
> Don Price
> ----- Original Message -----
> From: <rwbrpt@juno.com>
> To: <pianotech@ptg.org>
> Sent: Monday, February 19, 2001 7:27 PM
> Subject: Re: Steinway plate holes
> 
> 
> There are two principal reasons for this difference in tuning pin 
> hole
> preparation in the Steinway scales. The first is the closeness of 
> the
> holes (overlapping countersinks) in the center section. The second 
> is
> strength. Some of the scales have been prone to failure in this area 
> over
> the years and the small additional material helps strengthen the 
> web.
> Hope this helps clear up some of the mystery!
> 
> Bob Beck
> On Mon, 19 Feb 2001 17:21:10 -0600 Ron Nossaman 
> <RNossaman@KSCABLE.com>
> writes:
> >
> > >
> > >>
> > >>
> > >> Tradition.
> > >>
> > >>
> > >> Conrad
> > >
> > >
> > >
> > > Is this the real reason, or just your opinion of why they holes
> > are recessed?
> > >
> > >
> > > Wim
> >
> >
> >
> > That would be a yes, and a no. The holes are almost certainly
> > *still*
> > countersunk because of tradition, but there had to have been some
> > sort of
> > reasoning behind having done it in the first place and 
> establishing
> > the
> > tradition - whatever we might think of the reasoning now. I've
> > wondered about
> > it too, and didn't see it listed among Steinway's patents. Seems
> > like they
> > would have been proud enough of doing something to no apparent
> > purpose that
> > takes extra time in the manufacturing process to make a marketing
> > point of it.
> >
> >
> > Ron N
> >
> __________________________________________
> GET INTERNET ACCESS FROM JUNO!
> Juno offers FREE or PREMIUM Internet access for less!
> Join Juno today!  For your FREE software, visit:
> http://dl.www.juno.com/get/tagj.
> 
> 
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.