A laboratory course in woodturning

The practice of woodturning is an art relative to which there is little published, and there is, in consequence, little chance for arriving at conclusions as to the best method for performing any given operation; so there is a wide diversity in the methods by which different operators arrive at the same results. Some use one tool almost exclusively, while others use a large variety of tools.

The following exercises are designed to give the operator command of the more commonly used tools, using each for the operations for which it is especially fitted. The first four exercises are of special importance, and the operator is urged to continue the practice of them until he can perform them easily and safely; the operations involved in the third exercise, when mastered, will be found to give special confidence.

As the exercises have been arranged to give in the most direct manner, and without repetition, the typical operations of the woodturner, some learners may desire to add further practice in some or all of them, and, for the benefit of such, further exercises, involving similar operations, have been added in the form of an appendix. These have drawings, and, where necessary, additional instructions.

The operator is urged, however, to perform the regular exercise before attempting the added one. In woodturning the first essential is that the material being operated on be revolved on an axis with a fair degree of rapidity, and if this requirement be met, work involving great skill on the part of the operator may be accomplished by the use of rude and imperfect tools…

Some beautiful specimens of turned work have been made on the somewhat primitive tool shown in Fig. i. This rude lathe, on which the work is revolved between two pointed metal pins held in two blocks of wood, contains the essential features of all lathes. The sharpened pins give points of support between which the material being operated on revolves, and a bar of wood or iron, resting on the carriage, supports the cutting tool.

The Indian workman has a lathe even more rude than this, for his consists of two stakes driven into the ground, through which sharpened nails are driven to support the work, and revolution is given to the work by means of a cord in the hands of an assistant.

The principal features essential to all lathes are an axis of revolution for the material being operated on and some means for supporting and guiding the cutting tool, and the lathe shown in Fig. 2, the one in common use, differs from the ruder lathes just described in having these features in greater refinement.

In this lathe a metal spindle revolving in metal bearings determines the axis, and as this turns in one direction, the revolving wood has a movement that is steady, smooth, and continuous. The cutting tool is supported on an adjustable rest, and the speed of revolution may be varied within comparatively wide limits.

The degree of manual skill required to produce any required form is much less in this lathe than in the ruder forms first described.

Before starting to learn the operations of the woodturner, it is desirable that one should learn the names and uses of the tools he will have. Following are those in common use:

The Wood-Lathe, shown in Fig. 2, has as its principal parts the shears, the head-stock, the tail-stock, and the rest. The head-stock is fixed at one end of the shears, and the tail-stock and rest are movable along it, and may be temporarily fixed at any desired place by means of clamps.

The office of the shears is to support the head-stock and the tail-stock in such a manner that the axes of their spindles will be in the same straight line in whatever position on the shears the tail-stock may be clamped. A section through the head-stock is shown in Fig. 3. The head stock carries the live-spindle, shown at [a], and this live-spindle is the means used to revolve the wood which is being turned. Attached to the live-spindle is a cone-pulley, shown at [b], over which a driving-belt passes, and this belt turns the spindle. A fork, or some other device, is attached to the end of the spindle, and the wood being operated on is driven on this fork and revolves with the spindle. The spindle turns in bearings, or boxes, shown at [c], and [a]-[d] are oil-holes through which oil is supplied to the rubbing surfaces. The screw shown on the end of the spindle, at [g], is for the attachment of face-plates and similar apparatus. See Fig. 2. Very often end movement of the spindle is prevented by means of an adjusting-screw, shown at [f]. A couple of drops of oil ought to be put into each oil-hole when the lathe is first started. Removable caps are used to keep dust out of the oil-holes. The spindle is usually made hollow, and the live- centre may be pushed out of it by an iron rod passed through from the back end. The tail-Stock, shown in Fig. 4, supports the tail-spindle, [a], in which is held the dead-centre, [b], so called because it does not revolve. Between this dead-centre and the live-centre of the head-stock the material being operated upon revolves. The tail-stock may be fixed at any desired position on the shears by the clamp, [c]. The spindle may be pushed out from, or drawn back into, the tail-stock by means of the screw and handle shown at [d], and further movement prevented by means of the clamp-handle shown at [f]. The dead-centre may be taken out of the spindle, when it is desired to change it, by turning the handle until its back end strikes against the front end of the screw.

The Rest, shown in Fig. 5, is used to support and assist in guiding the cutting tool, and is adjustable along the shears in the same manner as the tail-stock. The distance of the tee from the work is regulated by means of the clamp that fixes it on the shears, and its height and angle with the work are regulated by the set-screw shown at [b].

When hollowed work, such as cups and boxes, are being turned, it may be fixed with its end inside the hollow, and so better support be given to the cutting tool.

The Fork-centre, shown in Fig. 6, is used in the live-spindle to make the work revolve, one end of the wood being driver on the fork-centre by a mallet, and then the Cup-centre, shown in Fig. 7, is brought against the other end. The cup-centre is held in the spindle of the tail-stock, and, in common with the cone- centre, is spoken of as the dead- centre. The cone-centre is used when metal is being turned. They are both shown in Fig. 7.

The Face-plate, shown in Fig. 8, is used when the work is of such character that it cannot be held between centres. It is attached to the live-spindle by the screw on the end, and is used in turning cups, balls, disks, and such other pieces as require that turning-tools be used on one end. The piece being operated on is not fastened directly to the face-plate, but is held in a wooden disk that is fastened to the face-plate by means of screws. This disk is called a chuck.

Face-plates are made in various diameters to suit the size of the work. When they are made more complex in character, as with raised rims and attachments in the form of adjusting-screws, they are themselves called chucks.

The swing of a lathe is twice the distance from the centre of the front end of the live-spindle to the nearest point of the shears.

The size of a lathe is determined by the swing and the length of the shears.

The Gouge, shown in Fig. 9, is the tool of greatest use to the woodturner. Any piece to be turned is first rapidly dressed to a rough approximation to the desired form by means of the gouge; and most surfaces having compound curves are shaped by its use. In the hands of a skilful wood-turner it may be made to do most of the work done in the lathe. The edge should be a smooth curve of the elliptical form shown, and the bevel should be straight, as it is the guide by which the depth and outline of curves are regulated. The elliptical form is necessary in order that it may be turned in a small space. The handle ought to be long in large sizes, in order to give command of the tool during a heavy cut. The size is determined by the width across the concave side, and varies from a quarter of an inch to three inches by eighths of an inch.

The Skew Chisel, shown in Fig. 10, is used in finishing straight outlined work, such as the cylinder and cone, and for making convex curves and beads. It is bevelled from both sides to the cutting edge, which, instead of being at a right angle to the side of the tool, as in the carpenter's chisel, is "skewed " slightly. This gives better command of the cutting edge, because of a better position of the handle. The edge ought to be straight and the bevel flat, as by these is regulated the depth of the cut. The size is determined by the width of the blade. The larger sizes ought to have proportionally long handles.

The smaller sizes of chisels having straight edges are sometimes ground in such manner that the edges are at right angles with the sides, to avoid the necessity for reversing them when in use. The Round-nose Chisel, shown in Fig. 1 1, is usually made by grinding the edge of a carpenter's chisel to the elliptical form of the gouge. This tool is used in cutting recesses where the use of the gouge would be dangerous. Skilful turners frequently use the gouge for nearly all the work for which this tool is commonly used.

The Parting-tool, shown in Fig. 12, is used for cutting off finished work. It has, however, a greater use, in conjunction with the calipers, in regulating the outline of work, by making a narrow groove that will have a diameter at the bottom equal to some principal dimension of the work, and to which the general outline will, later, be reduced. The seventh exercise involves this use of the parting-tool. Its size is determined by the width of its cutting edge.