Music Trade Review
Issue: 1926 Vol. 82 N. 25 - Page 38
Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
TECHNICAL^SUPPLY DEPARTMENT
William Br aidVftute,Technical Editor
Grand Action Regulating—the Key-
Frame and Handling the Keys Themselves
Second of a Series of Articles on This Important Section of the Piano Technicians' Work—Fit-
ting the Key-frame to the Bed—Testing the Front Rail—Easing the Keys
and Remedying Looseness or Tightness—The Damper Action
I
N The Review of May 29 I had something
to say about the action of the grand piano
and about methods of regulating it. In that
first article I got as far as the keys and left
the reader supposedly with the action out of the
piano and detached from the key-frame, while
the keys were being leveled.
Before putting the key-frame aside, however,
we should consider an important point. Most
modern grand piano key-frames are fitted with
threaded brass bolts tapped into the wood of
the balance rail between the sections of keys
and at each end, so that there may be four or
five of them altogether. The lower end of each
bolt passes right through the balance-rail and
the frame, ending in a flattened-out round foot
which rests upon the key-bed when the key-
frame is in its place. It is plain that if these
bolts be turned downwards the flat feet will
protrude beyond the level of the key-frame,
which will be forced upwards, especially if the
key-blocks are in place and screwed down so
that the key-frame is held rigidly in front at its
bass and treble ends.
Now, of course, it must be obvious that if
the balance rail were for any reason too low it
could be raised by the simple process of screw-
ing down these screws, but it must also be
equally plain that if the balance-rail be raised
in this way it will no longer be resting upon the
solid foundation of the key-frame. It will
rather be forced upward towards its middle
region, while it is held down by the key-blocks
at the two ends. Hence, evidently these bolts
should not be handled in this way. On the
other hand, they serve a very useful and prac-
tical purpose in facilitating the travel of the
key-frame across the key-bed. For this purpose
they should be adjusted so that the foot of each
is paper-breadth below the level of the wood
surrounding it.
Fitting Frame to Bed
Another point is equally important. Sonic-
times when one is playing a knocking sound is
heard as a key here and there is pressed down
on to its front-rail punching. Usually the trou-
ble is noticed near the center of the keyboard.
It is due to sagging of the key-bed or perhaps
warping of the key-frame. In either case there
Don't Lose Money
on Scratched Pieces
A new booklet, "How To Repair Damage To
Varnished Surfaces" tells how anyone can quickly
turn scratched, marred and damaged pieces into
extra profit makers. It tells how to fill holes and
scratches, how to remove packing marks, how to
match stains, etc. It is no longer necessary to sell
instruments at "marked down" prices.
Get the
profit of the full price. A copy of this valuable
booklet sent FREE upon request. Pin this ad to
your card or letterhead today.
The M. L. Campbell Company
2336 Pennway
appears a space between key-frame and key-bed.
When a key over such a gap is pressed down,
the finger presses also the key-frame down
through this gap on to the key-bed, making a
knocking sound meanwhile.
In order to overcome this very distressing
difficulty it is necessary first to lay a straight-
edge over the key-bed where the front rail of
the key-frame would ordinarily come. If the
bed is sagged in the middle, the straight-edge
will show the trouble. Next, the key-frame
being still stripped of action and keys, let it be
placed on the key-bed in the proper position,
and the key-blocks then be put in place and
screwed down. Now the balance-rail fitting
may be tested by knocking with the fingers near
the screw bolts above mentioned. If it appears
from the resulting sound that the key-frame at
the balance rail is not lying snugly on the key-
bed, the bolts may be adjusted cautiously until
there is no longer any sign of bad fitting.
The front rail may be tested in like manner.
Here any bad fitting will show at once. If it
appears that the key-blocks would solve the
problem if only they could be made to hold
down the ends of the frame more firmly, the
guides in the blocks may be lowered slightly.
When spring contacts are used between frame
and block-guides this remedy is unnecessary.
In the case of an old grand piano it is advis-
able to place a strip of cardboard, firmly and
neatly glued, under the key-frame front rail.
It should be glued, of course, to the rail and
not to the key-bed. This can be adjusted so as
to take up the dead space between frame and
bed. In new pianos the action finisher carefully
fits the frame to the bed and makes sure that
the two cling firmly to each other. Of course,
he receives both in perfect condition, but some-
times he has to use the plane and the sandpaper
on one or the other. Tn any case, it is always
William Braid White
Associate, American Society of Mechanical Engi-
neers; Chairman, Wood Industries Division, A. S.
M. E.; Member, American Physical Society; Mem-
ber, Rational Piano Technicians' Association.
Consulting Engineer to
the Piano Industry
Tonally and Mechanically Correct Scales
Tonal and Technical Surreys of Product
Tonal Betterment Work in Factories
1901
References to manufacturers of unquestioned posi-
tion In industry
For particular a, address
209 South State Street, CHICAGO
Kan«a» City, Mo.
SPECIAL SUMMER COURSE
Jane 1 to August 6, 1936
PIANO TUNING—ACTION
REGULATING AND REPAIRS
CO-OPERATIVE PIANO TUNINO SCHOOL.
The Y. M. C. A. of Philadelphia
1431 Arch Street
advisable to sandpaper the bottom of the frame
if it shows signs of roughness, and the same
with the key-bed. A little powdered graphite
along the track of the balance-rail bolts above
mentioned is also useful; but this means "a
little" only.
Easing Keys
Keys must be tested to see that they work
freely, but not loosely on the balance and front
pins. To this end, as each key is dropped into
its place it may be tested by lifting it up and
down a few times on the balance-rail pin to
see if it sinks into place readily, or, on the
other hand, sticks. If it sticks, the mortise
may be slightly enlarged with the key-easing
pliers. If it is too loose then the mortise is too
wide, and must be narrowed slightly. This may
be done by making a flanged wooden wedge,
with a narrow end to slip inside the mortise
and a flanged shoulder to rest on top of the
mortise about an eighth of an inch on each side
of the center hole. If, then, this wedge is
tapped with a hammer as it thus rests in place,
the wood will be slightly pressed inward be-
low the shoulder on either side. If the fell
bushing is too much worn it may have to be
replaced; but that is repairing, not regulatjng.
If the front of the keys are too loose in fitting
to the front-rail pins the remedy is to turn
these pins, which are oval, with the front-rail
key-spacing iron. When they are so turned
to one side or the other, their available trans-
verse section is enlarged. On the other hand,
if the keys fit too closely on the front-rail pins
they must be eased with the easing pliers.
Damper Action
Before the action is replaced for the action
regulating, and while the space above the key-
bed is still vacant, it is advisable to regulate
the damper action. This is not difficult, but
few tuners seem to know how to set about it.
The damper action consists essentially of
some seventy levers, turning on centers in
flanges and fastened to a frame or rail fastened
to the rear end of the key-bed. (It is well to
follow the description by examining from time
to time the actual damper action in a grand
piano.) Each of these levers has its outward
moving end resting upon a felt-covered squared-
out bed at the extreme rear of the correspond-
ing key, so that when this key is depressed in
front and rises at its rear the damper lever
rises also.
Attached to each damper lever by a center
pin, bushed as usual, is another lever, standing
upright and carrying a vertical wire, at the
end of which rests the damper felt or felts
carried by a wooden head into which the wire
is fastened. It is evident that the action must
be regulated to cause the damper lever to move,
carrying with it the vertical wire-carrying lever,
the wire and the damper head with its felts, as
soon as the key is depressed.
We Specialize in Piano Key Work Recovering,
Rebuilding, Repairing, 40 Years' Experience
Correct spacing and alignment.
All work done by
experts with most modern machinery. If you have
any broken keys or tops, send parts to us parcel
post or express.
Prices Low—ALL WORK GUARANTEED.
FKIELD MILLER ft CO.,
3767 N. Illinois Street
Indianapolis, Indiana
38
POLK COLLEGE
The Largest and Finest Piano
Trade College in the World
Personal instruction by lead-
ers in the profession. Sound-
proof individual studios, fin-
est equipment.
Complete
Courses.
Write for catalog
POLK COLLEGE OF PIANO TUNING
Polk Building, Laporte, Ind.
Tuners and Repairers
Our new illustrated catalogue of Piano and
Player Hardware Felts and Tools is now
ready.
If you haven't received your copy
please let us know.
OTTO R. TREFZ, JR.
2110 Fairmount Ave.
Phila., Pa.
TECHNICAL^SUPPLY DEPARTMENT
William Br aidVftute,Technical Editor
Grand Action Regulating—the Key-
Frame and Handling the Keys Themselves
Second of a Series of Articles on This Important Section of the Piano Technicians' Work—Fit-
ting the Key-frame to the Bed—Testing the Front Rail—Easing the Keys
and Remedying Looseness or Tightness—The Damper Action
I
N The Review of May 29 I had something
to say about the action of the grand piano
and about methods of regulating it. In that
first article I got as far as the keys and left
the reader supposedly with the action out of the
piano and detached from the key-frame, while
the keys were being leveled.
Before putting the key-frame aside, however,
we should consider an important point. Most
modern grand piano key-frames are fitted with
threaded brass bolts tapped into the wood of
the balance rail between the sections of keys
and at each end, so that there may be four or
five of them altogether. The lower end of each
bolt passes right through the balance-rail and
the frame, ending in a flattened-out round foot
which rests upon the key-bed when the key-
frame is in its place. It is plain that if these
bolts be turned downwards the flat feet will
protrude beyond the level of the key-frame,
which will be forced upwards, especially if the
key-blocks are in place and screwed down so
that the key-frame is held rigidly in front at its
bass and treble ends.
Now, of course, it must be obvious that if
the balance rail were for any reason too low it
could be raised by the simple process of screw-
ing down these screws, but it must also be
equally plain that if the balance-rail be raised
in this way it will no longer be resting upon the
solid foundation of the key-frame. It will
rather be forced upward towards its middle
region, while it is held down by the key-blocks
at the two ends. Hence, evidently these bolts
should not be handled in this way. On the
other hand, they serve a very useful and prac-
tical purpose in facilitating the travel of the
key-frame across the key-bed. For this purpose
they should be adjusted so that the foot of each
is paper-breadth below the level of the wood
surrounding it.
Fitting Frame to Bed
Another point is equally important. Sonic-
times when one is playing a knocking sound is
heard as a key here and there is pressed down
on to its front-rail punching. Usually the trou-
ble is noticed near the center of the keyboard.
It is due to sagging of the key-bed or perhaps
warping of the key-frame. In either case there
Don't Lose Money
on Scratched Pieces
A new booklet, "How To Repair Damage To
Varnished Surfaces" tells how anyone can quickly
turn scratched, marred and damaged pieces into
extra profit makers. It tells how to fill holes and
scratches, how to remove packing marks, how to
match stains, etc. It is no longer necessary to sell
instruments at "marked down" prices.
Get the
profit of the full price. A copy of this valuable
booklet sent FREE upon request. Pin this ad to
your card or letterhead today.
The M. L. Campbell Company
2336 Pennway
appears a space between key-frame and key-bed.
When a key over such a gap is pressed down,
the finger presses also the key-frame down
through this gap on to the key-bed, making a
knocking sound meanwhile.
In order to overcome this very distressing
difficulty it is necessary first to lay a straight-
edge over the key-bed where the front rail of
the key-frame would ordinarily come. If the
bed is sagged in the middle, the straight-edge
will show the trouble. Next, the key-frame
being still stripped of action and keys, let it be
placed on the key-bed in the proper position,
and the key-blocks then be put in place and
screwed down. Now the balance-rail fitting
may be tested by knocking with the fingers near
the screw bolts above mentioned. If it appears
from the resulting sound that the key-frame at
the balance rail is not lying snugly on the key-
bed, the bolts may be adjusted cautiously until
there is no longer any sign of bad fitting.
The front rail may be tested in like manner.
Here any bad fitting will show at once. If it
appears that the key-blocks would solve the
problem if only they could be made to hold
down the ends of the frame more firmly, the
guides in the blocks may be lowered slightly.
When spring contacts are used between frame
and block-guides this remedy is unnecessary.
In the case of an old grand piano it is advis-
able to place a strip of cardboard, firmly and
neatly glued, under the key-frame front rail.
It should be glued, of course, to the rail and
not to the key-bed. This can be adjusted so as
to take up the dead space between frame and
bed. In new pianos the action finisher carefully
fits the frame to the bed and makes sure that
the two cling firmly to each other. Of course,
he receives both in perfect condition, but some-
times he has to use the plane and the sandpaper
on one or the other. Tn any case, it is always
William Braid White
Associate, American Society of Mechanical Engi-
neers; Chairman, Wood Industries Division, A. S.
M. E.; Member, American Physical Society; Mem-
ber, Rational Piano Technicians' Association.
Consulting Engineer to
the Piano Industry
Tonally and Mechanically Correct Scales
Tonal and Technical Surreys of Product
Tonal Betterment Work in Factories
1901
References to manufacturers of unquestioned posi-
tion In industry
For particular a, address
209 South State Street, CHICAGO
Kan«a» City, Mo.
SPECIAL SUMMER COURSE
Jane 1 to August 6, 1936
PIANO TUNING—ACTION
REGULATING AND REPAIRS
CO-OPERATIVE PIANO TUNINO SCHOOL.
The Y. M. C. A. of Philadelphia
1431 Arch Street
advisable to sandpaper the bottom of the frame
if it shows signs of roughness, and the same
with the key-bed. A little powdered graphite
along the track of the balance-rail bolts above
mentioned is also useful; but this means "a
little" only.
Easing Keys
Keys must be tested to see that they work
freely, but not loosely on the balance and front
pins. To this end, as each key is dropped into
its place it may be tested by lifting it up and
down a few times on the balance-rail pin to
see if it sinks into place readily, or, on the
other hand, sticks. If it sticks, the mortise
may be slightly enlarged with the key-easing
pliers. If it is too loose then the mortise is too
wide, and must be narrowed slightly. This may
be done by making a flanged wooden wedge,
with a narrow end to slip inside the mortise
and a flanged shoulder to rest on top of the
mortise about an eighth of an inch on each side
of the center hole. If, then, this wedge is
tapped with a hammer as it thus rests in place,
the wood will be slightly pressed inward be-
low the shoulder on either side. If the fell
bushing is too much worn it may have to be
replaced; but that is repairing, not regulatjng.
If the front of the keys are too loose in fitting
to the front-rail pins the remedy is to turn
these pins, which are oval, with the front-rail
key-spacing iron. When they are so turned
to one side or the other, their available trans-
verse section is enlarged. On the other hand,
if the keys fit too closely on the front-rail pins
they must be eased with the easing pliers.
Damper Action
Before the action is replaced for the action
regulating, and while the space above the key-
bed is still vacant, it is advisable to regulate
the damper action. This is not difficult, but
few tuners seem to know how to set about it.
The damper action consists essentially of
some seventy levers, turning on centers in
flanges and fastened to a frame or rail fastened
to the rear end of the key-bed. (It is well to
follow the description by examining from time
to time the actual damper action in a grand
piano.) Each of these levers has its outward
moving end resting upon a felt-covered squared-
out bed at the extreme rear of the correspond-
ing key, so that when this key is depressed in
front and rises at its rear the damper lever
rises also.
Attached to each damper lever by a center
pin, bushed as usual, is another lever, standing
upright and carrying a vertical wire, at the
end of which rests the damper felt or felts
carried by a wooden head into which the wire
is fastened. It is evident that the action must
be regulated to cause the damper lever to move,
carrying with it the vertical wire-carrying lever,
the wire and the damper head with its felts, as
soon as the key is depressed.
We Specialize in Piano Key Work Recovering,
Rebuilding, Repairing, 40 Years' Experience
Correct spacing and alignment.
All work done by
experts with most modern machinery. If you have
any broken keys or tops, send parts to us parcel
post or express.
Prices Low—ALL WORK GUARANTEED.
FKIELD MILLER ft CO.,
3767 N. Illinois Street
Indianapolis, Indiana
38
POLK COLLEGE
The Largest and Finest Piano
Trade College in the World
Personal instruction by lead-
ers in the profession. Sound-
proof individual studios, fin-
est equipment.
Complete
Courses.
Write for catalog
POLK COLLEGE OF PIANO TUNING
Polk Building, Laporte, Ind.
Tuners and Repairers
Our new illustrated catalogue of Piano and
Player Hardware Felts and Tools is now
ready.
If you haven't received your copy
please let us know.
OTTO R. TREFZ, JR.
2110 Fairmount Ave.
Phila., Pa.
Future scanning projects are planned by the International Arcade Museum Library (IAML).