Up to about the year 1870, the square was the popular piano. The grand has always been too expensive for the great music-loving masses, and previous to this time the upright had not keen developed sufficiently to assert itself as a satisfactory instrument. The numerous objections to the square piano forced its manufacture to be discontinued a few years after the introduction of the improved new upright. Square pianos that come, at the present day, under the hand of the tuner, are usually at least fifteen years old, and more frequently twenty or more. However, in some localities the tuner will meet numbers of these pianos and he will find them a great source of revenue, as they are almost invariably in need of repair.
Compare the three cuts of actions in the study of this lesson.
The main constituent parts of the square action are similar in appearance to those of the upright; in fact, most of the parts are the same in name and office. However, the parts are necessarily assembled very differently. In the square action, the hammers strike in a vertical direction, while in the upright they strike in a horizontal direction; the motion of the key being the same in both.
Of the three types, the square is the simplest action, as many of the parts seen in the upright and grand are entirely absent in the square.
Beginning with the key, it has its balance pin, guide pin, cushions, etc., practically the same as in the other types.
The bottom, or key rocker, is reversed in the square; the end transmitting the motion being nearest the performer.
The extension and wippen are absent in the square, as the jack is attached directly to the bottom or key-rocker.
The back check is screwed to the key, and as the hammer head rests against it after striking, the use of the contrivance called the back catch in the upright is unnecessary.
The hammer rail in the square, in addition to serving its purpose as a rest for the hammers, also serves the purpose of the regulating rail, as you will see the regulating screw, with its button, attached to This rail is stationary in the square, not moving toward the strings and shortening the stroke as it does in the upright when the soft pedal is used. The soft pedal in the square piano simply interposes a piece of felt between each hammer and its corresponding string or strings. This felt being much softer than that of the hammers, the tone is greatly subdued.
The mechanical arrangement of the dampers is very different in the square from that in the upright. The dampers are above the strings. Instead of springs to hold them against the strings, they simply rest upon them with their weight. In many old squares some of the dampers fall upon nodal points, causing defective damping or harmonic after-tones.
The stationary parts of the square action are: action frame, to which is secured the balance rail, balance pins and guide pins, hammer rail, flange rail, and damper rail. When the key is struck, the parts that move upward are: the back end of the key, tottom, jack, hammer, back check, damper wire and damper lever. The hammer falls back upon the back check immediately after striking, and remains there until the key is released, when all movable parts fall to rest position.
The action of the jack is the same in all types.
After thoroughly going over the details of the action of the square and upright pianos, there remains very little to describe in the action of the grand.
The grand action partakes of the characteristics of both the upright and the square, and is somewhat more complicated than either.
The bottom and extension are almost identical with those of the upright; the extension, however, is necessarily very short.
The wippen is of different construction, and somewhat more complicated in the grand.
The flange rail in the grand is made also to serve the purpose of regulating rail, as the hammer rail is made to do in the square.
The back check is identical with that of the square.
The dampers are the same in their working principles as those of the square, but are generally different in construction; yet, some squares have the same arrangement of dampers as those shown in the cut of the grand action.
The soft pedal of the grand shifts the entire action to the right so that the hammers strike only two and in some cases only one of the strings.
The student should study the three types of actions from the actions themselves, if possible.
First, feel or look underneath the keyboard and see if there are screws that go up into the action. In most of the better grade instruments the action is fastened in this way. If the screws have square heads, your tuning hammer will fit them and bring them out; if common screws, a screw-driver will suffice. Look through the opening in the sound board where the hammers strike and see that they are all down before pulling out the action, lest they break off by catching on the under side of the sound board. This is almost sure to happen if actions are out of order.
In most square pianos, the narrow board just below the keys can be removed by being raised straight up, as it simply sets over screw heads in the key frame. When this strip is removed, a wire handle will be found in the middle of the key frame by which to draw out the action. In some cases, and especially in grands, this strip is secured by screws found underneath the piano. In other pianos, the action is held by screws in front of the key frame, which will be revealed by the removal of the front strip, above referred to.
Be especially careful in placing the action back into the piano. As a rule, it is safe to keep the right (long) end of the square action bearing against the right side of entrance, being sure that one end of action does not get ahead, which might cause some of the hammers to strike the props for which the openings are left in the back extremities of action.
While the action is out, study carefully the purpose of every part and its movements, referring to this and the previous lesson until you have thoroughly mastered the entire mechanism. Do not rest until you can name correctly everything you see and know its use so well that you could explain it satisfactorily to an inquirer. Sometimes the tuner is asked a great many perplexing questions and is expected to respond intelligently.
We have dealt with the three types of actions that are most commonly found in the three types of pianos. The student must bear in mind that there are numerous manufacturers of actions, and that each has his peculiar method of constructing his special action to bring about the desired results, which are practically the same in all cases; and consequently, while a variety of construction will confront the beginner in piano regulating and repairing, he will understand the construction and requirements of any action that may demand his skill from the foregoing instruction, if properly mastered. In this, as in all other mechanical professions, one's inventive genius must often be summoned to assist in surmounting obstacles which are sure to arise unexpectedly.