Music Trade Review

Issue: 1927 Vol. 84 N. 1

Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
TECHNICAL^SUPPIY DEPARTMENT
William Braid^I\nte,TechnicalEditor
The Wrest Plank, Its Functions and
Its Design, in the Scale of the Piano
The Steinway practice has always been to bed
the wrest plank into the arms of the case and
then fit the iron plate over it, using the iron
rib before mentioned, and also another iron
lug which projects forward and is fastened into
Wrest Plank Not Exactly a Massive Piece of Construction tor the Load It Has to Carry, and the head block at the back of the key-bed. All
this extra care is for the purpose of securing
Cdftsequently It Presents to the Scale Designer a Problem of No Little Importance
a
rigid, immovable wrest plank. I need hardly
—Another Article in the Series on the Design and Planning of the Piano Scale
point out that the difficulty here is in the neces-
HE last previous article in the scale draw- of the waste wire between the agraffe and the sary separation of the wrest plank from the
ing series appeared on November 27, tuning pin should be as short as it can properly main framing of the case.
when I was speaking about drawing in the be made. In the upper treble the capo d'astro
Pin Lengths and Plank Thickness
hitch-pin holes and treating the waste ends of bar construction calls for a length of wire be-
While on this subject we shall do well to de-
the strings. It is now time to think about tween the bearing edge of the bar and the edge cide in advance what thickness of wrest plank
drawing in the tuning-pin holes.
of the tuning-pin section of the iron plate. This we desire. I like a long tuning pin, and pre-
Our string lines, which indicate the middle length, however, should not exceed one inch, fer the size known as 0000X2^, that is to say,
:string or line of each unison, will, of course, but on the other hand the distance between this two and one-half inches long by a diameter of
have been drawn right up to the forward edge edge and the nearest tuning pin in each unison 0.28" or 0.29". Such a pin should penetrate into
of the iron plate, or rather to where that should be sufficient to prevent a steep slope of the wood of the wrest plank to a depth of not
forward edge will come; so that there should the wire, which always puts on additional strain less than 1V6" and if the tuning-pin plate be, say,
be no trouble whatever in seeing where at least at the point where the coil on the pin begins.
5/16" thick, that means that the length of pin
one tuning-pin hole for each unison should go.
Of course it is true that as the strings be- above the plate will be approximately 13/16".
Before, however, we begin to lay out these come longer and longer the amount of space
The wrest plank then should be built accord-
holes, we must take thought for a moment con- available for the treatment of length between ingly and should also be just so thick that the
cerning the wrest plank, especially as to the agraffe and pin becomes constantly smaller. bottom ends of the pins need not be pushed
best way of spacing the pins through it. A Thus, the longest strings are the worst off in quite through it. It is always better to have
wrest plank is not exactly a very massive con- this respect. We must take all possible care, the bottoms of the pins covered, even if only by
struction, considering the load it has to carry. however, not to have the length too short be- a very thin sheath of the wood of the wrest
It is evident at first sight that there must be tween agraffe and tuning pin, and must be plank.
enough wood between each pair of adjacent guided by the steepness of the slope. A slope
From what has been said, it is plain that the
pins to enable these to resist the pull of the of 10 degrees is quite enough.
tuning-pin holes must be bored in the iron so
tuned strings. On the other hand, if the space
On the other hand, if and when we can divide as to accommodate pins 0.29" in diameter. It is
between each pair be too great the pull across the slope into two parts, as by the interposition usual to have the holes, in fact, y 2 " in diameter
the face of the plank will be excessive.
of a pressure bar between agraffe and pin, the as finally bored. When drawing in the holes,
Other things being equal, we may start off angles may be greatly reduced in steepness, however, it will be sufficient to draw them of
with the general understanding that the length with consequent better tuning and much less the actual diameter of the pins, and then ap-
forward pull on the wrest plank.
pend a note to the drawing directing that these
In dealing with all these matters it is neces- holes be drilled to fit pins of size shown.
sary to keep in mind the great point that the
The question of bushing pins comes in here
wrest plank has to resist the forward stress and helps to determine the matter of diameter
imposed by all the two hundred and twenty-five of holes as bored in the iron plate. I think for
or more wires, which stress is constantly oper- myself that wooden bushings are unnecessary,
ating to move the plank towards the belly and that they do not add anything at all to the
bridge. That is why, of course, grand wrest stability or other valuable qualities of the planks are always fitted with an iron rib struction. They certainly do not help the pin
against which the plank may abut. Even when to sustain the strain upon it. At most they
thus supported, however, the grand wrest plank reduce slightly the unsupported length of the
is never perfectly rigid. Every tuner, I sup- pin, but they are not easily fitted closely enough
pose, knows that a well-made upright piano will to do even this effectively.
stand in tune better than a grand of equally
Our large stock ii rery leldom
It should be remembered too that the pins
depleted, and your order, whether
good construction, mainly because of this mat- are to be fitted into the wrest plank with a
Urge or ttnali, will receire imme-
diate attention.
In addition, you
ter of wrest plank construction. I personally
get the very best of
prefer to cast two iron ribs under the plate in
Felts— Cloths— Hammers —
such a way that the wrest plank is completely
Punchings — Music Wire —
boxed in. This, I think, makes for rigidity, of
Tuning Pins—Player Parts-
which, as I said before, the construction of the
Associate, American Society of Mechanical
Hinges, etc.
grand piano does not allow more than enough
Engineers; Chairman, Wood Industries
in this region.
We have In stock a full line of
Division, A. S. M. E.; Member, American
material* for Piano* and Organ*.
Physical Society; Member, National Piano
Technicians' Association.
The American Piano Supply Co.,
T
Remember Us
William Braid White
WHY SACRIFICE
YOUR PROFITS
T
HOUSANDS of dollars annually
are lost to dealers because of dam-
age to varnished surfaces, necessitating
reduced selling price. Tt is easy now for
you to repair those varnished surfaces—
and our little book "How to Repair
Damage to Varnished Surfaces" tells
you how. This will be sent to you free
upon request.
The M. L. Campbell Co.
loos W. 8th St.
Punchings
Washers
Bridle Straps
5814-37th Ave.
Kansas City, Mo.
George W. Braunsdovf, Inc.
Direct Manufacturers of
TUNERS' TRADE SOLICITED
Tonally and Mechanically Correct Scales
Tonal and Technical Surveys of Product
Tonal Betterment Work In Factories
References
to manufacturers of unquestioned
position in industry
For particulars,
address
209 South State Street, CHICAGO
Piano
Also—Felts and
Cloths, Furnished
in Any Quantity
Woodside, L. I., N. Y.
28
Consulting Engineer to
the Piano Industry
Tuners and Technicians
are in demand. The trade needs tuners, regu-
lators and repairmen. Practical Shop School.
Si'iul for Catalan M
Y. M. C. A. Piano Technicians School
52nd and Sansom Sts.
Philadelphia, Pa.
Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
29
The Music Trade Review
JANUARY 1, 1927
The Technical and Supply Department—(Continued from page 28)
slight backward rake, that is to say, leaning
slightly away from the agraffe line and towards
the front or keyboard end of the instrument.
The boring of the plate must be done accord-
ingly and should be so indicated.
Drawing in Pin Holes
Having settled all these matters, we may now
undertake to draw in our tuning-pin holes. I
find that in the treble sections it seems best to
space the pins so that the distance in a straight
line from the center of the hole for string num-
ber one to that of the hole for string number
three in each unison shall be 2 l /i". This allows
for a distance of \}i" between adjacent centers,
there being three pin holes for each unison.. Be-
ginning with unison number 88, one may place
the tuning-pin hole for its middle string at a
distance of say 4" from the center of the capo
d'astro bar, and immediately to the left of the
line of the string. Then the hole for the wire
which runs at the right (towards the treble
end) of the other may be placed \ l A" nearer
to the front edge of the plate (keyboard end)
and with its center point 1/16" to the right of a
line drawn through the center of the first-placed
hole. The third hole for that unison may then
be placed at the same distance in the opposite
direction from, and to the left of, the middle
hole. When I speak here of right and left I am
looking at the piano from a position in front
of the keyboard, as if playing.
It will be found that this distance from center
pin of any unison to center pin of the next
will, on this system, be %", which will exactly
fit in with the space of Y" between middle
strings of adjacent unisons at the hammer line.
The only exceptions to the rules here given
are of course, to be found if and when the longer
strings are slanted sufficiently to bring about
some crowding together of the pins. In the
spacing and slanting already laid out, however,
we have assured against any crowding among
the strings at the lower end of the understrung
sections.
The spacing of pin holes in the bass is, of
course, somewhat simpler, owing to the sub-
stitution of bi-chords for tri-chords. The same
principles of spacing, however, must be ob-
served, merely noting that there is more room
with bi-chords and that it is well in this case
to spread the pins as evenly as possible over the
wrest plank.
As a matter of practice it is always well to
lay out the drafting of these holes carefully be-
fore beginning to draw them in. One can
draw lines across the paper to indicate the
transverse positions of the three lines of pins
belonging to the tri-chord uniso- 3, thus fixing
the proper distances in that co-r linate. In the
other co-ordinate one may alsr draw lines at
right angles showing the 1/16' ,>actng above
mentioned. Then, with a sf : ::;_ bow compass
properly set, the circles car. ';, quickly and cor-
rectly described.
Bars
We may now begin to c : !?r the last of
our tasks, which are to A . :: '.he bars and
calculate their dime- ' :is I-MV' r with the
FAU5T SCHO9L
0. TUNING
M . . , . ! . , , ,\ ..I
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A l u m n i of •*>*«•. Inning. Pipr ltd K,<- »4 PLv... P,,m,.
y . . . Ro..l F . . .
i 7 2 M 1 . - . n %•.... -. M . o n
I ON
GREETINGS
A Happy New Year to one and all, for the
twenty-fourth consecutive time.
Correspondence
is solicited and should be addressed to William
Braid White, 5149 Agatite avenue, Chicago.
Distance Records Set
at Danquard Course
Tuners Come All the Way From Peru, South
America, to Attend New York Classes
The great interest taken by tuners and repair-
men in opportunities for gaining wider informa-
tion regarding the repair and maintenance of
player and reproducing actions was strongly
emphasized. At the recent sessions of the Dan-
quard Player Action School held in New York,
which was attended by a number of men who
came from considerable distances to receive
the instruction.
The distance record for the school was held
by Benjamin R. Domongues, of Peru, South
America, who attended all sessions at the
school. Next in line came G, J. Belair, of
Minneapolis, Minn., who, having missed the
classes held in Springfield and Peoria, 111., came
all the way to New York to attend the course.
Fred C Throm came from Rome, N. Y., and
several others who attended lived at points
well beyond the borders of the metropolitan
area.
This realization of the importance of a
thorough knowledge of the player and repro-
ducing mechanisms and means for adjusting
and repairing them is regarded as one of the
most prominent developments in the trade for
it means the proper servicing of instrument
Tuners Carrying Case
LIGHT—COMPACT—SERVICEABLE
Weighs Only 6 Pounds
Outside measurements 15j^ inches long, 7
inches wide, 8 inches high.
No. ISO—Covered with seal grain imitation
leather. Each $13.00
No. 200—Covered with genuine black cow-
hide leather. Each $20.00 F.O.B. New York.
When closed the aluminum
trays nest together over the large
compartment, which measures
137/ 8 " x 6" x 4". The two left hand
trays measure 13?/g" x 2%" x \y%
and the two right hand trays 13^s"
x3y^"xiy 8 ".
The partitions in
right hand trays are adjustable or
may be removed. Case is fitted
with a very secure lock and solid
brass, highly nickel-plated hard-
ware.
We have a separate Department to take care of special requirements
of tuners and repairers. Mail orders for action parts, repair materials,
also tuning and regulating tools are given special attention.
Ha: imacher, Schlemmer & Co.
Pi ::o and Player Hardware, Felts and Tools
New York Since 1848
OTTO R. TREFZ, JK
Av-.
is a great help in avoiding an ugly width in
the case and through the plate.
\1 \«iS
Tuners and Repairers
2 1 1 0 f airmounl
thickness of the iron at various points and the
levels of the various parts of the plate in re-
lation to bridges, sound board, etc.
The first thing to be considered is how much
stress is to be borne by the bars. If we take
the first section in the treble, from unison No.
88 to unison No. 59, or thirty unisons in all,
we may calculate the stress when the strings
are tuned as 3 x 30 x 160 pounds, which is
equal to 14,400 pounds. Now if we consider
the bar which bounds the extreme treble edge
of the plate, and which is very short, owing
to the shortness of the distance at that place
between tuning pin and high pin positions,
and if we then turn to the bar which is to run
across at unison No. 59, we shall see that these
two between them must carry 14,400 pounds
of compression. But the longer of the two
bars must also carry half of the stress of the
next lower section, which also contains thirty
unisons and of which the stress may be con-
sidered as approximately the same. Suppose
we say that the total stress of compression on
the three bars which support the understrung
sections from unison No. 88 to unison No. 29,
inclusive, is 30,000 pounds. One of these bars
is at unison 88, one between unisons No. 59
and 58 and one between unisons No. 28 and
27, the latter being the first of the overstrung
unisons. Dividing the stress among the three,
as we safely may because they have been
spaced accordingly, we find that each has to
carry 10,000 pounds. Now the ordinary al-
lowed load on gray iron columns in building
construction is 10,000 pounds compression per
square inch of cross-sectional area. That would
mean that we should only need an area of one
square inch. But we can allow a little more
than this, say 1% square inches, and that can
be obtained by almost any arrangement of
dimensions, allowing, however, for the fact that
the strength of a beam is as the square of its
depth, but only directly as its thickness. So
we make our bars as deep as we can, and then
we may make them conveniently narrow, whicli
Ph.I*. P
4th Ave. at 13th St.

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