Music Trade Review

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TECHNICAL^SUPPLY DEPARTMENT
William BraidWhite,7M/7/r Grand Action Regulating—Needling the
Hammers and Rounding Off Their Crowns
A Continuation of the Series of Articles on One of the Most Important Parts of the Piano Tech-
nicians' Work—Handling the Dampers and Making Sure That the Rise of Each of
Them is Right—Regularity of the Repetition Lever—Lining the Hammers
E left the hammers with their crowns on the key-frame. In doing this we shall be
untouched, but with the remaining por- wise to see that the screws running through the
tions of each properly filed. Before we action brackets into the key frame are tight and
now round off the crowns we must do whatever not overdrawn. When the action is entirely re-
needling may be necessary. Testing by sound placed we may set the entire mechanism upon a
will of course tell, a good deal about the condi- flat, steady table. Then we start in with the
tion of the felt. Usually some needling will be wippen, that is to say, the frame which sup-
advantageous.
ports the repetition lever, the jack and their
Needling is often very badly done. The di- accessories, the lower ends of which rest upon
rections given here will be found to run dead the capstans projecting from the keys.
against the practice of many otherwise good
First of all, one must see that the roller or
men. Yet what I here insist on represents the knuckle fastened on the underside of each ham-
only safe method.
mer shank rests square upon the grooved repe-
1. Never use more than three needle points tition lever. In older pianos it will often be
at one time, nor let these project more than found that a repetition lever here and there is
one-half inch from the handle. Use a handle twisted to one side slightly. In this case the
thick enough to be easily grasped in the fist. screw in its flange may be loosened, the whole
Stab the hammers on each side of the crown, wippen pushed over to the proper place and the
leaving the latter altogether untouched. Never screw tightened again. If this expedient seems
pick up the felt, never dig it out as if one were "to be too rough the flange should be loosened
digging potatoes, never do anything that will and a bit of paper glued to one side of it so as to
break up the fibres. Simply push down on each push it permanently out of place to one side
side of the crown into the felt radially, as if each or the other. This takes much longer, of
stroke were following the spoke of a wheel course, but is accurate when properly done and
down to the hub. No. 6 needles are good for virtually permanent.
this first softening.
When in this way the knuckle of each ham-
2. Remember that the object of needling is mer shank has been made to rest squarely upon
to restore the uniformity of the texture inside the groove of the repetition lever, we turn to
the hammer, making a relatively soft cushion the latter and test it to see that it is rightly
inside but leaving the outer surface hard.
supported by its spring. Study of the grand
3. Needle too little rather than too much. action shows, as I have explained before, that
When satisfied that the set of hammers has been the repetition lever must carry the weight of the
properly needled, round off the crown of each hammer when the action is at rest. The
hammer with the sandpaper file, being par- springs attached to it are intended to enable it
ticularly careful not to flatten the striking point. to do this. On some actions there is a single
Then blow away the felt dust and put the action large spring with two forks, one fork bearing
aside for the time being.
against the repetition lever and one against the
jack. Other actions have two separate springs.
Dampers Again
We now go back to the action regulating Again in some cases a spring may be strength-
proper. Where we stopped we had eased and ened by turning down a little screw which
prepared the keys and had tightened the action. bears against its coiled end. In other cases one
Before putting the latter on the keys, however, has to bend the wire. In whatever way the
springs are mounted, let them be just sufficiently
it will be advisable to regulate the dampers.
I have already carefully described the action strong to enable the repetition lever to carry the
of the three pedals of the piano, but in dealing hammer without dropping. This much will do,
with the dampers the regulator will find some at least, for the time being.
That much attended to, we turn to the jack
points not before noted. The first thing to do
is to make sure that the rise of each damper is and line it up with the knuckle or "roller" under
right. This rise should be approximately three- the hammer-shank. On some actions this can
sixteenths inch above the string, when the key
is at the end of its downward movement in
front. If the key frame is put in under the
dampers before the action is in place, with
weights on the extreme key of each section, as
Associate, American Society of Mechanical
already suggested, the damper rise can be reg-
Engineers; Chairman, Wood Industries
ulated on each of the corresponding dampers
Division, A. S. M. E.; Member, American
Physical Society; Member, National Piano
and from these all the others can be regulated
Technicians' Association.
accordingly, with the keys out, by putting a
straight edge over the damper blocks.
Consulting Engineer to
I have already spoken of the adjustment of
the damper felts to lie square on the wires,
the Piano Industry
and of how to test the sostenuto action.
Tonally and Mechanically Correct Scales
We may now proceed to put the action back
Tonal and Technical Surveys of Product
W
William Braid White
be done by means of a small regulating screw
leaning against an iron spoon. In others it is
necessary to glue a small piece of very soft
felt against the rear end of the groove in the
repetition lever. Most modern grands to-day,
however, have the convenient regulating button
and screw.
In most actions also to-day a line is scratched
across the groove of the repetition lever to
assist in lining up the jack. Where there is no
such indication it is necessary to line up with
the hammer knuckle directly, by seeing that the
front edge of the jack lines up with the center
of the little wooden strip which carries the felt
of the knuckle. It is, however, not necessary
to line up each and every jack separately in
this way but the two extreme jacks of each sec-
tion and one in the middle should first be ad-
justed and then with a straight edge the work
on the others may be done quickly enough, with
the hammers conveniently folded back on their
flanges.
A good deal of friction is developed by the
rubbing contact of the jack with the knuckle
and it will be noticed that the jack is carefully
blackleaded in order to reduce this resistance.
Used grands frequently show the black lead
worn off and in this case it is advisable to rub
on a little powdered graphite which may then
be burnished down by rubbing with a heated
steel bar.
We now turn to the hammers again. They
must now be lined up in relation to the strings
so that the distance of travel for each one may
be 1^ inches. This is something which, unlike
the parallel case in the upright piano, cannot be
done directly against the strings. In the up-
right, the hammers line up against the hammer-
rail and the striking distance adjustment is
easily made by means of this rail, after which
the capstans are adjusted to take up any lost
motion or to relieve any crowding among the
moving parts. This, however, cannot be done
with the grand action, which must be adjusted
while it is still outside the piano. It is there-
fore advisable to rig up a temporary device of
some simple kind, whereby a string may be
stretched across the line of hammers at the
correct height. In order to avoid mistakes due
to the action being out of regulation, it is best to
measure the height of this string above the table
on which the action has been placed, which of
course must be equal to the height of the strings
(treble) of the piano above the keybed as
measured from inside the latter. I suppose it
is hardly necessary to remind the reader that
the bass hammers are made longer than the
others in order to accommodate their travel to
the higher bass strings which cross over the
others. They therefore must be regulated ac-
cordingly, that is by placing the string for them
at a height above the table equal to the height
of the bass strings above the keybed.
If desired another string" may be stretched
across after the first string has been adjusted
This second string, of course, will have to be
17/g inches nearer the table than the first. The
hammers may then be lined up with this second
string by turning the capstans on the keys. Or,
failing this, the extreme hammers of each sec-
tion may be carefully lined up to sit \Ji inches
below the original string and then with a
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