This is the last part from a series of articles by W. H. Davies of Liverpool published in London in The English Mechanic and World of Science in July and August, 1878, you can also read parts 1, 2, 3 , 4 and 5 and download a scanned version from Google. The piano he describes was old fashioned at the time and uprights haven't been manufactured in this form for a long time, and Mr. Davies' services and patterns, as well as the "small work" he recommends, are no longer available so some options might be considered if you follow his directions. I edited and broke it up a little, and reproduced some of the illustrations as vector drawings. The front pictures are of workers regulating pianos in 1899 at the Prescott Piano Company of Concord, New Hampshire from "Our Only Piano Factory" by Henry B. Colby.
Part 6 describes installing a repetition action and fitting the pedals.
Step 1: HOW TO MAKE a PIANOFORTE-VI.
The check action I have selected is that know as the "Molyneux," as it combines simplicity (and is comparatively easy to put together) with thorough efficiency. There are, no doubt, other double actions that equally fulfil these conditions, but I think and (by the time the regulating is satisfactorily accomplished) I am sure the amateur will agree with me that one is quite sufficient.
The patent of this action having recently expired, it may now be readily procured and at greatly reduced prices - viz., from 50 shillings upwards, according to the quality of the hammers. It may be obtained from the late patentee, Messrs. H. Brooks and Co., and Messrs. J. Nott and Co., Kirkwood-road, N. W., and probably at most small-work makers.
Step 2: Keys
As the keys of this action work in front of and not under the lever rail, as in the hopper action, they must either be 1in. shorter, or the action frame placed that much further back. In diagram Fig. 2, page 515, it will be seen I have allowed a greater space between the key-bottom and strings than is absolutely necessary, so that the latter method can be adopted.
As before, the keys are just taken in hand, the process being exactly similar, omitting the morticing.
Step 3: Action Frame
The action frame is also put together in the same manner, the measurements being slightly different. The top of the lever rail for instance is only three inches above the key-bottom, and is flush with the bottom of the standard, and 17in. from inside the lock-board.
The centre wire of the hammer rail is 41/2 in below the top bridge pin, and the space between these two rails being greater, advantage may be taken of it to insert another called the "stretcher rail" midway between them, for the purpose of strengthening the action frame, which is then fixed, and the hammers, key-frame, and damper rail put in as described.
Step 4: Stickers and Levers
The length of stickers can be ascertained by deducting 5/8in. from the space between the key and hammer butt (the hammers being close to the strings), or by that between the top bridge pin and key-bottom, less 5 3/4in.
As the stickers are supplied with the damper wire holes already clothed, it will be necessary to adjust the length of the wires to their respective dampers, the difference in length between the extreme ends being about 5/8in. It is better to rivet the wire in their places as they are put in, by giving to each end a slight turn before cutting off.
The levers are then glued into the groove made in the stickers (see diagram, Fig. 1), which are hung by simply hooking the spring into the loop in the hammer butt, A, Fig. 1, the levers being at the same time fastened to their rail, so that the stickers are evenly spaced, and immediately over their respective keys ; before doing this examine each sticker separately, to see that their regulating screws, B, Fig. 1, are all turned out level with the back, and that the springs are at their full power.
Step 5: Regulating
The hammer rest can now be screwed to its place, so as to allow a blow of 2 1/4 in., and the stickers adjusted to the notch in the butt by turning the screws in the keys at C, which are covered with a cloth flap, until the nose of the sticker is within half a card of the notch.
"Make the touch just so deep (which will be about 5/16in.) that when the hammers are block[sic] against the strings, the keys will just touch the surface of the baize, then turn in the regulating screws, B, sufficient to take out the blocking, but still to allow the hammers to be carried close up to the strings, and to escape with the weight that will press the keys down to the baize, which will be from 2 1/2 to 3 ounces, after which regulate the checks so as to allow the hammers to fall off about 3/8in. from the strings,"* and test with the finger if the check has a firm hold of the hammer, so that a rebound is impossible, and the shaky feeling of the keys under the fingers, resulting from an imperfect check, avoided.
If these directions are carefully carried out, the result cannot fail to be pre-eminently satisfactory, for while the tone is of that pure quality and ring characteristic of check actions, the repetition is unimpaired and fully equal to that of the single action, and, as the practised performer will easily perceive, on account of the check so readily releasing itself, the hammer seems as if perpetually balanced on the finger, and is always under perfect command.
This is the bright side. On the other hand, a double action imperfectly or carelessly regulated is so far inferior to the hopper action that instead of performance being a pleasure it is the reverse, and is, indeed, almost impossible to play on at all.
'* Mr. Molyneux's personal directions.
Step 6: Pedals
We will next proceed with the pedaling. The pedals are first let into the plinth at the middle, and about 4in. apart ; they are then marked about 3 1/2in. from the front.
A pair of rockers are got out of 1in. hard wood, extending from inside the bass end to about an inch beyond their respective pedals, and a screw put through the middle to the inside bottom, A, Fig. 2. When in place, measure from the outside of the plinth to the centre of each rocker, and bore the pedals for the tap of the screw at the same distance from the mark.
They are then put in, and this hole pricked through to the bottom, and holes bored from this with a 1in. centre-bit to allow the screws to pass without fear of touching. Let the point of this bit mark the rockers, and there bore for the screws, B. Fig. 2. This will insure the holes being exactly over those in the pedals.
The motion is conveyed from the rockers by means of pedal rods, C ; that of the left hand or soft pedal to an action crank (see diagram), shifting the hammer rail sufficiently to put the action on one string, and that of the loud pedal through the damper rail rest, and lifting the front of the rail, so that the dampers hang free of the wires.
Step 7: Key Levelling and Nameboard
The keys are now levelled to a thin, light straight-edge by means of touch-papers placed on the centre-pin, or by taking a shaving off the key, as may be necessary, and the hopper springs regulated to a uniform strength, the blocks fitted at each end of the keys, and the sharps cut to about 4in., and blocked.
The name-board is placed behind the keys, and fills the space between them and the back piece of the fall ; it is held in place by a tongue and groove at each end, and it is finished over the keys with an edging of red cloth.
Step 8: Toning
The piano may now be considered as finished, and requires only a few final touches, such as taking the action frame to pieces and carefully cleaning the various parts.
The hammers, also, will require a little "toning," or the quality so regulated that it may be equally brilliant or mellow throughout. For the former a clean hot iron is lightly passed over the faces of the hammers, and for softening they are pricked with a set of toning needles until the requisite quality is attained ; the treble notes are generally better for a little brightening with the iron.
Liverpool. W. H. Davies.
from the English Mechanic and World of Science vol. 27, no.700 August 28, 1878