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.
QUESTIONS ON LESSON IV.
- From a philosophical point of view, which do you consider the easiest and most perfect of the three types of actions? Also give reasons.
- Considering the wippen and its attachments as one part, how many parts move when a key is struck in the upright piano? How many in the square?
- Name the parts found in the upright action that are absent in the square.
- Describe the three methods by which soft tone is obtained from use of soft pedal in the three types of actions.
- What rail serves two purposes in the square action, and what are they? What rail serves two purposes in the grand action, and what are they?