CHAPTER XIII.

REGULATION OF PIANOFORTE TOUCH MECHANISM.

We may presume that the reader is by this time quite familiar with the appearance and use of the various parts of the grand and upright pianoforte action, both as assembled and detached. We may therefore proceed to give general instructions for the adjustment of these within the instrument and the regulation of the various working parts into proper harmony with one another.

We say “general instructions” advisedly; for it is quite out of the question to teach action finishing and regulating by means of written directions. Experience and the practical routine of the shop must be gone through by anyone who hopes to be able to do this kind of work well. For there are few departments of mechanical endeavor that demand such skill, care, and patience as the regulation of pianoforte mechanism.

Nevertheless the directions that we shall give in this chapter will be sufficient to make him who reads and digests them a very efficient critic. It is much to the employer to be able to estimate correctly the value of each practical detail of the construction, and the correctness of the manner in which it is executed. This chapter is intended to provide as much of this knowledge as may be imparted by means of written words.

We shall begin with the grand action, following the method that has been pursued throughout this work.

The first step in the regulating and adjustment of the grand action is taken by the “action-finisher.” He receives the action and keys separately. The former is without hammers or dampers and the latter without rockers or capstan screws. The action has to be placed within the space destined for it in the instrument and the proper position for it noted. If the action has been well made there should be no difficulty in seeing that it fits its place correctly. The action is screwed on to the key-frame through its metallic brackets and the capstan screws are put into the keys at the proper points so that they engage with the cushions on the bottom of the wippens. When this has been done the weight of the action upon any one of the keys should be noted and the action may then be removed. A piece of lead should then be taken and fastened to the back of each key. This lead must have the same weight as the action has upon each key. The keys will then remain in their proper positions when the action is removed, and the work of leveling them may then be begun. Remembering the depth of touch that was prescribed in the last chapter, let the extreme bass and treble keys be adjusted to an equivalent height by wooden blocks through their front rail pins. Then run a straight edge over the keys and proceed to adjust their levels by means of the thin paper punchings that are provided for the purpose. These come in various thicknesses and are laid over the balance rail pins and under the cloth punchings that must first have been placed in position both on the balance rail and the front rail. When the leveling is accomplished let the action be screwed on again. Then let the hammers be glued on. The striking point of the hammers must be carefully measured and the directions already given as to the striking of the highest hammer must be observed. It will be remembered that one-tenth of the string was recommended for the highest hammers, graduating down to the ideal one-ninth and one-eighth. The scale draughtsman will prepare a marking stick showing the true hammer line. The hammers are glued on absolutely at right angles to the plane of the strings. After they are dry, they must be adjusted to the proper position by the capstan screws or rockers. They must lie just over and not quite touching the wippen cushions. Let them also be aligned to each other, horizontally, with great exactness. Be sure that the keys work easily and that the depth of touch is roughly adjusted as already provided for.

It next becomes necessary to fix the damper mechanism. This is chiefly situated in the back of the action and the damper levers are to be so adjusted that they rest a little above the backs of the keys, ready to be engaged with them when the fronts of the keys are depressed. The dampers must fit on to the strings straight and must drop with sufficient force to effect an instantaneous damping. The damper levers are leaded for this purpose.

The instrument is then taken in hand by the action regulator. His work is most important. He first sees that the level of the keys is perfect and that they are properly balanced when suspended without the action. If any defects are found here they are remedied by changes in the leading. The keys should be so leaded that they balance when tested on a scale and the weight of touch with the action fitted must not be more than two and one-quarter ounces.

The alignment of the hammers is then corrected and the length of the hammer stroke, as laid down in Chapter XII, is adjusted by means of the capstan screw or rocker. The jack is so regulated by its button and screw that the trip up of the jack occurs when the hammer is 5/32 of an inch from the string. The checks must catch the hammers when they have fallen three-quarters of an inch away from the strings. The tails of the hammer-moldings must be roughened and the checks be so slanted that the catch is sure and tight.

The escapement lever is then considered. The spring that governs it requires adjustment. It must be sufficiently strong to cause the hammer to dance and jump a little on the lever when the key is released. The escapement lever must also be regulated by means of the hook that is found at its rear end. There must be space enough between the hook and the lever to ensure that the catch of the hammer by the check is at all times free. The screw that regulates the rise of the escapement lever must also be attended to. It is necessary that the movement of the lever be arrested before the hammer has quite risen to the point of the trip up of the jack.

The after-touch under the front of the keys is regulated by means of paper punchings. If enough punchings are placed under the keys to make very hard pressure necessary to force a release of the hammer, then punchings of 1/32 of an inch in thickness must be removed to make the after touch correct.

The keys must also be made to descend evenly as judged from the top. Unevenness is corrected also by the judicious use of punchings. In regulating the dampers there are many small details to be watched. The lifter-wires must work freely in the bushings and the heads must lie straight upon the strings. This is especially important as regards the bass wedge-dampers. There must be a small space between the damper levers and the felted backs of the keys and the rise of the damper heads when the levers are lifted must be even and facile. The height of ascent of the damper heads must not exceed one-fifth of an inch, and a little more when the whole of them are lifted by the pedal-rod. The sostenuto rod must also be adjusted so that the damper lever tongues are caught when the rod is revolved. Care must be taken that the rod does not catch the tongues when the pedal is not in use.

The pedal mechanism is simple. It is essential to see that the feet work in the lyre without scraping; hence lubrication with graphite and tallow is necessary. The rods that connect with the action levers must so engage as to be just in contact without bearing too much. The soft “_piano_” pedal must engage with the shifting lever so as to allow a small space between it and the point of contact with the key-frame. The strength of the reaction spring in the case must be arranged so that the key-board is pushed back with promptness upon the release of the pedal. The “_forte_” pedal must be adjusted so that its connecting rod is in contact with the damper lever lifting rail, but not enough to operate without the depression of the pedal. The sostenuto pedal requires to be arranged to revolve the sostenuto rod instantly. Here the rod has to be revolved its entire distance before it operates and the adjustment may therefore be made quite close.

These directions will enable one at least to be sure that the regulation of a grand pianoforte action has been properly done; although it is not to be expected that the innumerable small details of practical work are to be learned other than practically. It must especially be borne in mind that the use of tools and facility in handling them and making definite adjustments with them is a matter of long and patient practice. The above instructions are intended merely to set the routine method before the reader, so that he may approach the subject with a correct knowledge of principles.

The regulation and adjustment of the upright action is precisely similar as to principles. The differences occur through the somewhat dissimilar method whereby repetition is attained and the great variation in the general position of the parts with reference to the strings.

The action of the upright is fastened, by means of the metallic brackets, to iron bolts which are set up in the key-bed. The height of these bolts depends upon the dimensions of the instrument and the striking point of the strings. In setting the action in place great care must be exercised in seeing that the hammer line lies truly in regard to the run of the strings. Errors in the casting of the plate often lead to a distortion of the true string-line and the action finisher must take care to set the action with due regard to these matters. When the action, which is minus hammers and dampers, is thus set in, the keys may be placed under it for the purpose of marking the points where the capstan screws or rockers must be set. The hammers and dampers are then glued in and adjusted for position with regard to the strings. If the action and keys are truly proportioned, it is always possible to make the length of the key just as recommended in the last chapter. Sometimes the size of the pianoforte makes impossible the employment of capstans or rockers with abstracts. In this case it is customary either to use a dowel prop or to lay the wippen directly upon the key. When the dowel prop is used it is driven firmly into the key, and its upper end, which is a wooden rod into which the lower spike is screwed, impinges against the wippen. In laying the place for the dowel to be driven, it must be remembered that it is necessary for the head of the dowel to hit the bottom of the wippen squarely. But the dowel describes a curve at its head when the key is moving, and the wippen has to be provided with a felted foot, curved so as to accommodate this circular motion of the dowel. This motion must be observed carefully, so that the dowel does not lay too far forward or back of the wippen foot when the key is at either of its extreme positions. The regulation proper now begins.

Abstracts, or dowels, are always regulated by a screw. This is either in the form of a capstan or of a rocker, or of the movable part of the dowel itself. The adjustment must be made with reference to the position of the jack under the hammer butt. It is necessary that the jack be just in contact with the notched heel of the butt. After the hammers and dampers have been put in and their positions with reference to the keys adjusted, it becomes necessary to regulate the escape of the hammer by means of the regulating buttons and the jacks. The directions given for grands apply here. The hammer springs must be put in place and the fall of the hammers noted. If they stick, the bushings are too tight or some cognate trouble exists which can be easily remedied with a drop of oil on the affected part.

The checks must be adjusted to the back-stops and made to stand square to them and they must also be arranged to catch the back-stops when the hammer has recovered about two-thirds of an inch from the string. We know that the length of the hammer blow should be from 1-24/25 of an inch in the bass to 1-9/10 of an inch in the treble.

The tapes must be adjusted so that they begin to exercise their pull when the hammer is started away from the strings. They must not be strained too tight, but should be left just a little loose, so that when the soft pedal pushes the hammers towards the strings the abstracts or dowels do not at once leave the keys.

The dampers are adjusted, as to position, like those of the grand--that is, they must lie square on the strings and be in a straight line with one another. Their movements are directed by the spoons and these must be so bent that the damper begins to move when about one-third of the angular motion of the key has taken place. When actuated by the pedal, they must fall against the back of the hammer spring rail, which is felted for the purpose, and their motion must be instantaneous when the pedal is depressed. The pedal mechanism is concealed behind the bottom frame of the case and will be found to be precisely similar to that of the grand, except as regards the mounting and pivoting of the levers. These must be kept lubricated with graphite and tallow to prevent squeaking. The connection of the soft pedal with the hammer rail must be close so that instantaneous action results when the pedal is operated. The motion of the pedal may push the hammers one-half of their stroke length towards the strings, not more.

The leveling of the keys and the regulation of touch have already been described; nothing further need be said except that these operations are more easily performed in the upright owing to the open way in which everything is set in.

It is unnecessary to go further into detail in regard to the regulation of actions. Enough has been said to lay bare the general principles, and, as was stated before, the rest comes from experience only. A text-book can never replace an apprenticeship, but we cannot deny its value in laying down correct principles for the man who wants to know how things should be done.

As a fitting conclusion to the present discussion, we may now note the order of the various processes which combine to make up the manufacture of a pianoforte, from the cutting of the lumber to the final tuning in the wareroom.

The various kinds of lumber that are to be used are exposed, after cutting and rough dressing, in a lumber-yard. Here they remain from three to ten years according to the kind of wood and the degree of care that is taken by the manufacturer. The best makers take the greatest care in seasoning their lumber.

The first operations to be considered are those of the saw-mill. Here the rough work for the case-making is done, and the moldings for actions and cases are turned out. The rough cases are then sent to the case department and made up into shape. The bent rims are there glued together for the grands, and the sides and frames of the uprights are shaped. The back framing, wrest-planks and other parts of the case and back construction are also put together in the case department.

In the meantime, the machine work has gone in the rough from the saw-mill to the “action department,” where it is cut, shaped and made up into the delicate action parts. These have to be leathered, felted, provided with brackets, springs and the other accessories and assembled. The hammers are covered, dampers, prepared, and the whole of the action work is thus made ready against the time when the case shall be in condition to receive it. This action and hammer work is generally done by specialists, who supply many different makers with actions according to their particular scales and patterns.

Meanwhile the cases have been sent to the varnish room and are here prepared with filler and stain to receive the varnish finish. The best instruments have their cases left about four months in the varnish room, receiving eight or ten coats at intervals of ten days or more.

While this is going on, the sound-board department is occupied in preparing the sheets of spruce for manufacture into sound-boards. Here great care and skill are necessary to obtain the proper gradation of thickness at all parts of the board’s surface. When the boards are finished, they are put into drying rooms, to remain until wanted for ribbing, bridging and insertion within the instruments.

The first operation in the assembling of the parts is performed by the “bellyman.” He takes the sound-board, ribs it and affixes the bridges according to pattern, bores the tuning pin holes in the wrest-plank, and fastens on the iron plate, which was cast to pattern in the iron foundry, to the back, upon which the completed sound-board has by this time been glued.

Then the “stringer” receives the bellied back, puts on the strings and pressure bar (if the latter is used instead of agraffes). The first rough approximation to pitch is then made by the “chipper,” who pulls the strings up roughly two or three times in succession at intervals of about twenty-four hours.

The case is then turned over to the “side-gluer,” if the instrument be an upright. The case of the grand is incorporated with the back and is put together before the bellying. The side-gluer affixes the sides and key-bed of the upright and also the bottom-board, which contains the trap-work for the pedal mechanism. If the instrument be a grand this department confines itself to the fitting and adjustment of the lyre. After the sides are thus affixed the case is returned to the “flowing-room,” where the final coat of “flowing” varnish is carefully applied. This requires ten days to dry hard.

The case is now ready for the “action finisher.” His work of setting in the action and keys and putting the instrument into rough playing condition has been described in detail.

The pianoforte is then given its first rough tuning by the “rough-tuner,” who surrenders it in turn to the “fly-finisher.” In this department the top and bottom frames, fall-board, panels, key-blocks, name-board, key-slip, hinges, music desk and other parts of the cabinet work are adjusted and fitted. After fitting they are removed from the case and sent to the “polishing department” to be made ready for the final setting up.

The next operation is performed by the “action regulator.” His work, which includes the finishing touches to the adjustments made by the action-finisher and side-gluer, has already been gone over in detail.

The instrument is by this time ready for another and somewhat more careful tuning. Here appears the “second tuner.” The instrument then is permitted to remain in its existing condition until two more tunings have been given at intervals of a week.

The “fine-regulator” next takes the instrument and proceeds to review the work of the action-regulator and correct any deficiencies in touch or repetition that may have been effected by the pounding of the rough tuners.

The “tone-regulator” is next called upon, and his delicate work is needed to give to the pianoforte evenness of tone throughout and an agreeable quality.

Then the polishers rub down the sides, the smaller parts being already polished as noted before, and give to the instrument its glossy and mirror-like finish. The “setter-up” then puts the various cabinet work parts together and the “fine-tuner” gives the final tuning. Lastly, the superintendent looks over the whole work, and woe betide the unlucky wight who has slurred or skimped his part.

The details listed above are, of course, subject to variations in the order in which they are performed. The variations are according to the practice of individual shops. Of course, it may at any time be required to give more tunings, especially if the pianoforte is left on the floor of the factory very long. But there should never be less than four or five.

When the instrument is sent to the wareroom or shipped to the dealer extra tunings are given according to the caprice or knowledge of both.