Cylinder Falls

These are rigid falls travelling in a circular path and are more wasteful of space than a tambour front, and are therefore rarely, if ever, used in modern work. The construction is worth recording, nevertheless. A typical example is shown in 247:4, and in designing these falls proper allowance must be made for the method of assembly. In 247:5, where the fall is



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246 Fall flap details
247 Secretaires, cylinder falls, and stationery cases

approximately half the total depth of the carcass, the top containing the fall must be made up as a separate unit so that the fall can be entered from the bottom, while in 247:6, where the fall is less than a true quadrant, entry can be from the back. In both cases the thick lock rail, which can have a shaped or recessed handle grip, is tongued to receive the cylinder fall and is glued in position after assembly. The fall itself can be constructed of laminated veneers or two sheets of thin 1/8 in (3 mm) plywood pressed between sawn formers/forms, or coopered as in 247:8. The latter method is probably more positive, although difficult to make, for it will keep its shape, whereas laminated falls tend to spring back a little after release from the cramps/clamps and the flattening of the curve must be established by trial and error. Face and balancing veneering can be done either between shaped cauls or formers or in a vacuum-press, or more simply by the traditional hand method with hide glue. In the best work the fall is tongued at the sides to engage in a circular groove worked in the carcass sides (247:7), with 3/16 in (5 mm) or 1/4 in (6 mm) falls entering the full thickness, and the lock rail can have shallow tongues or can be cut back as shown. If the fall is not grooved into the sides there is always the danger of the end rubbing and scarring the polish, for it is virtually impossible to prevent a certain amount of side play in the quadrant arms, but a curved cover fillet can be fitted on the outside to cover the rub. Methods of swivelling the fall are shown in 247:5, 6 which will have to be specially made out of sheet brass or steel, pivoted to a screw plate and either flanged for screwing to the fall, or side screwed to a shaped block glued to the fall. Figure 247:8 shows a slotted bar movement cut from 3/16 in (4.5 mm) mild steel which pulls the writing-top forward as the fall is raised. The bar is screwed to the fall but free to rotate and slide on a centre pivot screwed to the carcass side and another pivot on the writing-flap, and the length of the slots which control the movement can only be established by making full-size drawings of the closed and open positions. With all these movements the stationery case must either have independent sides set in to allow free passage of the metal arms, or distance-pieces (247:8X, X) for the slotted bar movement. A closing fillet (Y) can also be fitted to close the gap at the top. The locking rail can be fitted with a box or piano lock. Antique examples of cylinder falls show the falls coopered up out of very thin stock, reinforced with glued canvas at the back.

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Wood Working for Amateur Craftsman

Wood Working for Amateur Craftsman

THIS book is one of the series of Handbooks on industrial subjects being published by the Popular Mechanics Company. Like Popular Mechanics Magazine, and like the other books in this series, it is written so you can understand it. The purpose of Popular Mechanics Handbooks is to supply a growing demand for high-class, up-to-date and accurate text-books, suitable for home study as well as for class use, on all mechanical subjects. The textand illustrations, in each instance, have been prepared expressly for this series by well known experts, and revised by the editor of Popular Mechanics.

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