Practical Organ Building

by W. E. Dickson

CHAPTER X.

THE DRAW-STOPS.

We have provided no means as yet for bringing the sliders under the control of the player. The mechanism by which this will be effected must depend upon our plans for the case and book-board.

Method 1.—As we have only five stops we may have resolved to arrange the knobs in a horizontal row above the key-board, and below the edge of the book. We shall soon see that this arrangement will result in much convenience and simplicity.

The ends of the sliders project at each end 2 or 3 inches beyond the margin of the sound-board. To the cheek of the wind-chest, below these projecting ends, will be screwed a stout balk of oak or mahogany (say 2½ inches square), constituting a bridge, and having stout levers, after the manner of backfalls, working in notches. These levers should be of oak, birch, or other hard wood, at least ½ or ⅝ inch in thickness, and not less than 2 inches wide; and the pins on which they work should be very stout, say ¼ inch in diameter, and should be held down in their places by slips of hard wood firmly screwed down to the bridge. All this is sufficiently shown in Fig. 46, and it will be quite plain to the comprehension of every reader that these levers (like backfalls) may be askew to the straight line of the bridge, so that while their upper ends spread out to reach the sliders, their lower extremities may be brought into any position convenient of access.

Fig. 46.

The arms of these levers will of course be of unequal lengths. About 2 inches, or a trifle more, will be found a sufficient and agreeable play for the draw-stops. If the sliders have a play of 1 inch only, it is clear that the lower arm of the levers must be twice the length of the upper arm. At any rate the adjustment of the play of the draw-stops to that of the sliders should be made in fitting these levers, and not in any other part of the mechanism. The upper end of the lever, shaped into a tenon or tongue, will enter a square aperture in the end of the slider, and the edges of this aperture should be bevelled, in order that the lever may bear equally upon it in all positions. Rub the end of the lever with blacklead, and use this wherever there is friction of wood against wood.

The levers being fitted, three at one end and two at the other, or all the five at the same end, as may best suit the position of the wind-trunk, the form of the frame, and other considerations, it will be easy to connect them with the draw-stops by means of squares or bell-cranks.