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How To Make An Organ Keyboard.

By

M.W.

The delicately-poised and accurately-constructed keys in a modem instrument present a great contrast to those in organs built in the Middle Ages, the keys of which are several inches wide, and so heavy that they required beating in order to move them, from which circumstance a performer on the instrument was termed an organ-beater. The physical exertions required to play on such a keyboard must almost have equalled those of Gulliver when entertaining the court of Brobdignag with a musical performance, and of which he remarks that "It was the most violent exercise I ever underwent" The description of an ancient keyboard may have furnished Dean Swift with his idea in this case. In the keyboard at present in use, the natural notes of the chromatic scale are generally shown by white keys, while the sharps and flats are indicated by raised black ones. Even this is a reversal of the ancient practice, for the natural notes were black, and the sharps and flats were white. In some instruments bf the present day, especially in those of Gothic design, the old order of the colours has been revived. I may mention that in the fine old organ at Exeter the old keyboard is still preserved.

 

Many amateurs who are engaged in building the small organ described in these pages have expressed a wish to be supplied with instructions for making the keyboard, so that the instrument may be truly described as being "all their own work." To enable them to gratify this laudable ambition, I will now endeavour to explain how the keyboard can be satisfactorily made; but I must here impress upon all who intend to attempt this task, that every part of the work must be most accurately and carefully executed, or the keys will be a source of annoyance instead of pleasure.

 

Fig. 1Before starting on the keys themselves, it is necessary to construct the frame, of which a general idea will at once be gained on an inspection of the plan in Fig. 1. It consists of two sides, called the cheeks, and three rails, termed the front, middle, and back rails respectively, and a cross rail in the centre, to add strength. All the wood to be either oak or mahogany.

First prepare the cheeks, which are I foot 6 1/2 inches long, 3 1/2 inches high, and 1 1/2 inch thick. The front and back rails are 2 feet 9 1/2 inches long, 3 1/4 inches wide, and 3/4 inch thick. The middle rail is the same length and width, but is 1 1/8 inch finished thickness, worked to the shape shown in the section, Fig. 5, and the top of it stands B inch higher than the top of the front or back rails. The cross rail is 3/4 inch thick, and supports the other three. All the rails are dovetailed together and secured with screws, this plan beings better suited for the purpose than mortises and tenons. The cheeks are a few 7 inches apart in the clear. The front and back rails should now be covered on the top with thick green baize, to secure silent action. The appearance of the keyboard will be much improved if the front portion of the cheeks is cut out, as shown in FIG 2Fig 2, and the front edge should project 1/4 inch beyond the front rail to receive the bead, which runs along the front of the keys, to hide the gap between them and the key-rail. This bead should be 1 1/4 inch high, and 1/4 inch thick.

Having now completed the key-frame, the keys themselves should be commenced. They may be made of good mahogany or lime. Good yellow pine may be used, provided the wood be a board of BĚ inch stuff -- mahogany, cut in harder pine, mortises hereafter to be described wood, and let into the keys at the proper joint whichever you intend to use--with the running grain across it, plane both sides very truly square all the edges. The finished size of it is to be 2 feet 7 inches long, and I foot 6 inches wide. With a compass, pencil, and T-square, set out the keys, as shown in  Fig. 3. First draw the lines A, B, C, D, E, and F, at the following distances from the front edge of the board:--A. 3/8 inch ; B 1 5/8 inch ; C 2 1/8 inch; D 5 1/8 inch; E, 9 inches; and F, 9 5/8 inches. The lines A and C show the position of the front pins in the white and black keys, E and F the mid pins, and B and D the front and back edger; of the combs or raised black keys. After drawing these:tines, set out the white key lines, each of which is exactly 15/16 inch apart. The compass of this keyboard is to be from CC to G in the alto, but if a smaller or larger compass is required, the board must be proportionately reduced or extended in length. There are thirty-three white keys, and the size above given allows a inch to spare. Then mark out the black keys, taking notice that they do not come in the centre of the white ones, but to the left or right of the centre as required, the object being to get as much room as possible on the white keys between each black one. The blacks are arranged in alternate groups of two and three. Fig. 6 shows more plainly how the groups of three black keys are arranged with regard to the white ones. It will be as well to score across the black keys with a lead pencil, to distinguish them, or you may make a mistake in boring the pin mortises. When you have marked this all out glue a slip of the same wood as the board all along the front edge. This slip need only be 1/8 inch thick, and it should be secured to the end of each key, as marked out, with two little pins or brads as well as with glue. Over this slip glue another of chestnut 1/4 inch thick, and if you intend to have the front of the keys moulded, run the moulding on this slip (see Fig. 4) This moulding, though not much used at the present time, is an easy way of finishing the key fronts, is cheaper than ivory, and looks better than plain flat wood. The board now being prepared, fasten it down on the key-frame, with its front edge level with the edge of the lower rail, and with a centre-bit the exact size of the key-pins, bore the holes for the key-pins right through each key into the rails of the frame. You will thus have no difficulty in getting the pins exactly in their right places.

Take the board off again, and cut the mortises which should be done with a proper tool, viz., a chiselpunch. If you cannot get this, use a small mortise chisel, the same width as the key-pins. The underside of the holes for the mid pins should be left untouched, but the top part is formed into a mortise; or slot, about 1/8 inch long, and the width of the key-pin, the pin being in the centre. The mortises must then be cleared with the clearing tool if you can possibly get one, or if not, you must do the best you can with the mortise chisel. The clearing tool--a small centre-bit, the centre of which is as thick as the key-pin--is inserted through the top mortise, and, on turning it, the wood is cleared away all except about a inch at the top and bottom. The shape of the hole, when finished, is shown in  Fig. 5. The object of this internal enlargement is to prevent unnecessary friction of the key on the pin, and the liability of sticking. The holes for the front pins have the slot or mortise at the bottom, and the top is bored out with a centre-bit, about 5/16 diameter. In the white keys this hole is covered with a slip of thin wood which runs right across the key, and is let into it, as shown at A in Fig. 4. The black keys will not require this slip as the holes are covered by the thick ebony. Having completed the mortises, go over the tops of the keys (where the ivory platings are to come) with a fine toothing plane, and then give them a coat of size and flake white, to prevent the wood showing dark through the ivory. Lay out your ivory platings, match the fronts and tails, and number them, keeping the whitest ones for the treble keys, and then shoot the edges for the joints with a finely-set steel plane. Glue the fronts in their places with white Russian glue, and when they are all on, clamp a strip of heated hard wood over them, and leave them to dry. The tail-pieces are what is termed sprung on, which is done as follows :--drive a small French nail into the key, just a little within the distance to which the back of the ivory would reach, and you will have to slightly bend the ivory plating to get it into its place when glueing it on. Be careful not to let any glue get into the joint between the two ivories, or it will show as a dark line, but if the joint is properly made, it should be scarcely visible. Rub the ivory well down, and clamp a strip of wood on it the same as with the front pieces. When you draw out the nails, fill in the holes with some stopping coloured to match the wood. If you intend to face the nosings of the keys with ivory veneer, that should now be done, but if you have circular nosings, as shown in Fig. 6, they must be formed after the keys are cut apart

When the glue is thoroughly dry and hard, you may scrape the key platings with a steel scraper, taking care to keep the scraper in a diagonal position across the keys to prevent the joints working up. Rub them down with fine worn glass-paper, and then polish them well with a damp linen pad, and finely-powdered pumice stone. Take great pains with this part of the work, or the keys will not look nice. The keys may now be separated by sawing down the lines with a thin fine toothed saw, and the black keys may be cut from the white with a stout fret saw, or a thin mortise chisel.

The white keys must be sloped back where they butt on the end of the black ones, as shown in Fig. 4, and the black keys are hollowed out on the underside where they cross the mid-rail. The keys may then be gone over with a fine set plane to take just the roughness of the saw marks off; finishing off with the scraper, and fine glass-paper, but be careful to take off no more than absolutely necessary. Now drive your key-pins into the holes already bored for them in the rails of the key-frame, and be careful to have them upright; the sections will show how high they project above the rails. The mid-pins should have a small dise of soft leather, or felt, fitted on to them for the keys to rest on, in order that wood may not rattle against wood. Place the keys in position, and fit on the ebonies so as to leave the least possible gap between them and the white keys. The ebonies are generally sloped at the sides and front edge, but the latest improvement is to make them quite square at the sides, and circular on plan at the front. The extra width at the top is a great acquisition, and there is less liability to catch the finger-tip against the end of the black key when playing rapid passages of music. Should the keys require any loading to balance them proptrly, a hole should be bored through the side of the key with a centre-bit, and the lead forced into it, as shown by the round dots near the tail end of key in Fig. 2. Lead forthe purpose may be purchased in small round sticks.

Immediately behind the combs or ebonies, there is placed a bar of hard heavy wood, about 3/4 inch thick, lined at the bottom with a piece of thick red baize. This bar, which is called the thumper, rests on the keys, and runs loosely in a vertical groove in the key cheeks at each end. Its use is to prevent the keys rebounding, and so causing a cyphering of the notes when playing rapid chords.

The section  Fig. 6, shows the connection with the key action where the keyboard is made to slide in. This is a convenient arrangement, as the keyboard can be shut up like a drawer when not in use, thus keeping it out of harm's way, as well as giving more room in the apartment. A disc of thick cloth is glued on the end of the key-tail, and over this is glued a piece of soft leather, thus forming a circular lump, highest in the centre. On this, the lower end of the sticker rests, the sticker being prevented from shifting laterally by being cut oblong in shape, and passed through a hole in a rail termed a register. The rail, or register, need not be more than 3/8 inch thick, and 1 1/2 inch wide, and the sticker is prevented from dropping any lower when the keyboard is pushed in, by a piece of wood glued on it. The top of the register should be covered with soft leather to prevent noise.

Ivory, pins, baize, etc., can be purchased in London of Mr. T. Dawkins, 17, Charterhouse Street, E.C. I have endeavoured to make these instructions clear, but an inspection of a keyboard would be a great assistance to the amateur.

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This page last updated 10/01/97