One piece, to form the back centre, may now be fixed to a base, say four inches long, cut from the same strip. A holding-down bolt, consisting of a half inch coach bolt, long enough to go through the bed, with one-and-a-half inches to spare, is then fitted to it. A butterfly or winged nut is put on in place of the ordinary square or hexagon one, and a washer must be put over it to bear against the underside of the bed. The screw to form the back centre should measure half-an-inch to three-quarters of an inch in diameter, and be pointed. It can be obtained at an ironmonger’s. This is forced into the hole bored through the wood, and will hold well without further precaution.
The mandrel head-stock is fixed together by means of one or two long bolts going quite through it lengthways. A nut on each end will draw the two end uprights into close contact with the bottom piece, and will prevent the head-stock from spreading open when the mandrel tail-pin is screwed up tight. It is essential that this wooden head-stock should be made as solid as possible, and one made of iron would be more serviceable. The former can be made by a wood-worker, whereas the latter entails engineers’ work, and probably for this reason is not invariably met with in wood-turners’ workshops. The wooden head-stock may be bolted on to the bed by the aid of coach-bolts.
The mandrel, usually made of iron, and its collar, which may be of steel, or of some softer metal suited for bearings, must be procured from an engineer. It would be impossible for a wood-turner to make these with his usual appliances, and not only will it be better, but cheaper, to buy the mandrel and collar. These will have to be fitted to the head-stock. A tail-pin screw is wanted to support the tail end of the mandrel, and should be obtained with it. The making of the mandrel head-stock is work altogether more fit for an engineer. A fast and a loose pulley have to be fitted on the mandrel to take the strap from the driving-shaft.
The hand-rest—or T rest as it is more properly called—consists of a casting which forms the socket, and of a second one, which is the T. These may be bought at many iron foundries. A holding-down bolt is wanted to secure the socket-sole. For convenience of shifting, a butterfly or bow-nut is preferable to a hexagon or square one.
A skeleton lathe of the most simple and inexpensive form has been briefly described above, so that an idea of the very primitive tools now employed may be formed.
Fig. 2 shows a wood-turning lathe of more substantial construction. It has the bed and standards made of iron. The mandrel projects on the left end, and has a threaded nose to receive chucks; by this arrangement discs of large diameter, say up to six feet, such as table-tops can be turned. When used in this manner, the mandrel nose must either have a left handed thread or be run the reverse way. The chucks would be unscrewed from an ordinary right-handed thread by the action of the tools.
Fig. 3 shows a lathe specially adapted for ornamental work. It will produce spirals of any size, pitch and form; shape prisms of any sectional form, parallel or tapering; and may also be used as an automatic lathe working to a template. The slide-rest carries a revolving spindle, which is driven from an overhead countershaft, and cutters of any desired form can be fitted into this. When used for fluting, the cutter spindle is brought into action, and, if a spiral is desired, the mandrel is slowly rotated by means of gearing from the leading screw. Quick or slow twists are got by altering the wheels to suit. The chuck, shown on the mandrel-nose, serves the purpose of a division plate in spacing fluting. A template is shown in the illustration, and the upper slide of the rest is kept against it by the action of the weight, also shown.
Fig. 2. WOOD TURNING LATHE ON IRON BED.
Fig. 3. LATHE FOR STRAIGHT AND SPIRAL FLUTING.
In contrast with the lathe first sketched may be considered some of the automatic machines which are used in turnery. An American “Variety” lathe is illustrated in Fig. 4. This machine is constructed to produce large quantities of uniform articles at a minimum of cost, to effect which rapidity in working is most essential. An idea of the mode of operating this lathe may be inferred by reference to the illustration. The headstock to the left is fitted with a chuck, which receives the squared wood just as it comes from the saw mill; the right-hand end of the wood is supported by a collar, mounted on a carriage, which travels along the lathe-bed. This collar is fitted with a cutter, arranged to turn the square wood down to a parallel cylinder of definite diameter. The poppet-head is actuated by a lever handle, shown on the right, having its fulcrum about a pillar to the rear of the bed; the lever is jointed, and is attached to the barrel of the poppet. Suppose the rough wood is placed in position, ready for operating upon. By pulling the lever handle, the poppet-head is brought up towards the carriage, and as soon as the former touches certain regulating screws on the carriage the latter is also moved. The effect of this is to turn the wood to a certain diameter, the length being determined by regulating screws. Simultaneously with the operation, the wood may be bored to any diameter and depth required by means of a boring tool fixed in the poppet-barrel.
So far the process is merely to rough out the work. Any mouldings or shaping that may be wanted may then be made by a series of cutters fixed in the tool-box, shown just to the right of the collar. This tool-box is brought towards the work by pressing the knee-pad, shown near the centre, between the standards. The same operation also brings a parting tool into action, but this tool does not act till the last moment.
These operations, so difficult to describe clearly, are performed with such rapidity that about three seconds suffice for going through the whole series and producing a finished article from the rough material. The work that can be turned out in this machine is almost endless in variety and exact uniformity is assured.
Wooden boxes, bobbins, knobs, handles, egg-cups are amongst the many objects that can be successfully made on this machine at a speed of about 1,000 an hour. Turning, boring, and beading being carried on at the same time, the lathe running at some 3,000 revolutions per minute. The price of this lathe is from £50 to £65, including freight from the United States.
Fig. 4. AMERICAN VARIETY WOOD TURNING LATHE.
Fig. 5. WOODEN SHOE.
Fig. 6. SHOE LAST.
Fig. 7. PISTOL STOCK.
Though turning is often considered as limited to the formation of circular work, yet lathes are constructed to produce objects of a widely differing form, such as wheel spokes, gun stocks, boot lasts, curved handles, as used for axes, &c. Several specimens of this kind of turnery are illustrated in Figures 5 to 12. Such work is produced on copying lathes, and examples of these are shown and described in a subsequent chapter. The examples of work are introduced thus early in the book in order that the reader may