Part 4

There are also many cheaper firms than those alluded to, where the work is rather of rough-and-ready style; all depends on what _class_ of work the would-be purchaser proposes to engage in, whether he intends to confine himself to plain hand-turning in wood, to the construction of steam engine, and other models of machinery in metal, or to the more beautiful finished work in hard wood and ivory, which develop the full power of the machine itself, and the skill of the accomplished turner. In the former cases, a very plain and inexpensive lathe will suffice. In the latter, it is absolutely necessary to purchase one of the best construction, at a tolerably high figure.

The best advice to those of slender means, and who, therefore, vastly predominate, is to sacrifice all else to the mandrel and collar. The latter may be bought at from twenty to thirty shillings, ready for mounting in detached wooden headstocks, and will be far superior to any that an ordinary smith can produce. In this case, the two poppets that carry the mandrel and centre screw should be connected together by a block of wood between them, which latter may be rounded off and shaped to something near the form of a cast-iron headstock.

The only care necessary in mounting such a mandrel, will be to keep the axial line parallel to the lathe-bed, and directly over the centre of the latter. Whether the mandrel is thus a separate purchase, as may happen from necessity, or obtained as part of the lathe, and fitted in a cast-iron headstock, it should certainly be hardened, and also the collar, if of steel. Both will take a higher polish for this process, and will run easier in consequence. The cost of such a mandrel is rather greater, because many warp or split in the process, and have to be thrown aside; and the labour of grinding mandrel and collar to an exact fit, is considerably increased. The gain, however, is greater than the loss to the purchaser, and the extra outlay must not, therefore, be grudged. It is very annoying to find a conical mandrel worn down by the collar after a twelvemonths' work; for a collar is thus formed on the conical part, so that it cannot be tightened up by the back screw.

The first tool to be noticed is the gouge, the form of which is a longitudinal section of a tube, and is shown in Fig. 41. Of this tool not less than three sizes should be selected, of the respective diameters of one inch, half-inch, and a quarter or three-eighths. When purchased, they require grinding, the bevel being too short. It is essential that this tool and the turning chisel have a long bevel, so that the cutting edge should be a very acute angle. (Fig. 41, not like 42.) It is impossible to do good work with the latter form of tool which is, nevertheless, of frequent occurrence in the workshops of amateurs. Both gouge and chisel must be sharpened on an oilstone (Arkansas or Turkey will be found the best) to a keen edge, _and no pains must be spared in preserving the tools in this condition_. Three sizes of chisel to match the gouges should be selected. The latter tool is not made like that intended for carpenter's use, with the edge at right angles to the sides, but is sloped like Fig. 43, so as to present an obtuse angle A, and an acute one B, and the cutting edge is central, the bevel being alike on both sides, so that the tool may be turned over, and used with either of the flat sides upwards. The handles of gouges and chisels should be much longer than those used by carpenters, and nicely rounded and shaped in the lathe. The most difficult thing to turn being a cylinder of soft wood; a description of the method of effecting this will be the best means of initiating the novice in the art of turning. In all the most perfect work by practised hands, there is a sharpness of edges and roundness of mouldings, that are exceedingly agreeable to the eye, and bespeak at once keenness in the tool with which the work has been done, and steadiness in the hand of the operator. The novice must aim at similar perfection, and to this end he must determine to avoid the use of sand-paper, and trust to his management of exceedingly keen tools to put a workmanlike finish to his work. To commence with the proposed cylinder. Let a piece of sound beech be selected for the first essay, as being less difficult to manage than deal, the grain of the latter tearing up in long shreds under the action of the tool. The first thing to be done, after sawing off the necessary quantity of sufficient diameter for the proposed work, is to round it off roughly by means of the hatchet and draw-knife, or spoke-shave. The next thing is to mount it in the lathe. For this purpose the prong chuck, or, better still, that represented as an improvement on the latter, and shown in Fig. 23B, must be screwed on the mandrel, and the work made secure by the aid of the back poppet centre. Care should be taken that the piece runs truly between the points of support, and that it revolves steadily without shake. There is no real necessity for using the compasses, or other contrivance for finding the exact centre at each end, as sometimes recommended, neither, indeed, is it always possible thus to find the axial line. It is easy to fix it at first lightly in its place, and ascertain by a turn or two of the mandrel, how nearly it runs as it ought to do. If it seems tolerably true, a turn of the back centre fixes it securely, if not, it can be shifted in any direction at pleasure. The tyro ought, however, to be warned that he is likely to be deceived in the size of the rough piece, and that he may very probably think it of sufficient diameter for the proposed work when in reality it is too small. Practice, or the use of the callipers, which are bow-legged compasses for measuring the diameters of work, will soon settle the question. The piece being properly fixed in the lathe, the latter is to be set in motion by means of the treadle, the rest having been first fixed as near as possible without touching the piece, and the T clamped parallel to it. If the tyro wishes to become a proficient, no pains must be spared to acquire the knack of working the treadle without moving the body to-and-fro. He must learn, therefore, to stand firmly on one leg, and after the wheel has been put in motion, he must let it and the treadle have its own way. He will thus soon _feel_ when the crank has passed the dead point at the highest point of revolution, and the proper moment to bear down with the foot. It is not necessary to describe the precise movement, as a few trials will teach the method much better than any written description. At first it is hard work, and constant change of leg from the right to the left, and back again, will have to be resorted to to diminish the fatigue. Practice will, however, remove all difficulties, and allow the whole undivided attention to be given to the management of the tool.

The gouge must be held down firmly on the rest with the hollow side upwards, and the bevel of the edge forming a tangent to the work, Fig. 44. In this position it will cut freely and smoothly, and the edge will be preserved. If held horizontally, as in Fig. 45, it is evident that the fine edge of the tool will be immediately destroyed by the rapid blows it will receive as the rough wood revolves in contact with it. Its tendency in the latter position will be to scrape, instead of cutting, and the fibres of the wood will thus be torn out in threads, and the surface of the work be roughened. The gouge, then, being placed in the former tangential position, the right hand grasping the handle, the left the blade, as in Fig. 46, the tool is to be slowly slid along the rest, and a series of light shavings, more or less continuous, will be removed from end to end of the piece. Let the workman bear in mind that the tool is to take a firm bearing on the rest, and that it must not move to-and-fro with the inequalities of the piece to be turned. It is not necessary to remove large chips unless the turner has acquired from practice perfect command over the tools, and for the adept this chapter is not written. After the most prominent inequalities have been removed, the _side_ of the gouge will come into use instead of the extreme end, and with this the work may be rapidly reduced to its intended size, always allowing, however, for the final cut with the chisel. Before the latter is taken up, the piece of work is to be rendered as level and true as can be done by the aid of the gouge alone; indeed, if the latter is of tolerable size, and skilfully used, a finish can be put upon the work by it almost equal to that which the chisel can produce and if the work in hand were a moulded pattern, with hollows and raised work, great part would have to depend on the gouge alone. In the present case the chisel must be used, and the method is as follows: Take a hold with both hands, as directed for the management of the gouge, but instead of the flat part lying evenly on the rest, the tool must be partly raised from it, so that only the lower edge takes a firm bearing. By this means the upper angle of the cutting edge (_generally_ the most acute) is kept clear of the wood, and the latter is cut away only by means of the middle and lower part of the edge, as shown in Fig. 47. If placed as in Fig. 48, the acute angle, _a_, is sure to catch and stick into the work, spoiling in two seconds all that has been done. The chisel can be used with either of its flat sides upwards, and moved along the rest from right to left, or from left to right, or turned upside down, as Fig. 49, so that the acute angle is downwards. These positions are shown in the Figs. 47 to 51. The only care necessary is to keep the upper point clear, allow the chisel to rest as flatly on the wood as the above precaution will permit, and to take as _fine_ and _continuous_ shavings as possible. The chisel will be found to draw itself along in some degree as the cut proceeds, and when this action is felt, it is doing its work properly--still, it is a difficult thing to use a chisel well, and the tyro will fail many times and oft before he will succeed.

The chances are that this initiatory lesson will result in anything but a correct cylinder--the surface will not be true like a ruler, but if tried by a straight edge it will be seen to be wavy. Tested by the callipers, Fig. 52, one part will be larger than another, even if the extreme portions be tolerably true to the proposed gauge. Now, the best turner on earth found just these difficulties, and nothing but perseverance and resolute determination will overcome them. Never mind spoiling the first piece of work, give up making it of a determined size, but do not give up making it a true cylinder. Keep the callipers at work, and gently level the prominent parts (you must work down to the size of the deepest hollow, for you cannot fill up such valleys like a railway engineer; you must throw down the adjacent hills instead), proceed gently, little by little; make the tool obey you, show it (as Ruskin speaks of pencil and brush) that you will not yield to its caprices and "henceforward it will be your most obedient servant." Having done the best you can with the surface of your cylinder, proceed to square up the ends, and mind the angle at this part is a right angle, _square_ and _sharp_, not rounded off. Now this again requires care and a knowledge of the proper method. You will work chiefly with the lower corner of the chisel, and we shall best describe the management of the tool by supposing the cylinder an inch too long, and that the extra piece is to be removed. Now there are three positions in which the chisel can be placed to bring its lower corner in contact with the cylinder. First, with the blade perpendicular to the work; secondly, with the blade inclined to the left, Fig. 53, as if to round off the end of the piece; thirdly, inclined to the right, Fig. 54. Held perpendicularly it will cut a fine line, but penetrate slightly; alternately in the other positions it will remove a V-shaped piece, and thus the cutting off is to be begun. One side of the cutting, however, has to be perpendicular, the other may be as sloping as convenient. Now, it is to be remembered in cutting the upright side, which is the end of the roller, the chisel is to incline _rather to the right_, for this reason,--if it incline to the left a momentary inattention will cause it to take the path _a, b_, Fig. 55, the tendency being to cut a spiral track towards the left. The experiment may be made by gently resting the edge thus inclined on any part of the roller, when it will describe a spiral at once. To the right, then, the chisel must _slightly_ incline, and it will cut off a thin curling shaving like Fig. 56, leaving the end of the piece quite smooth and shining. When the piece is nearly cut off, great care and lightness of hand must be used, as the central portion will have become weak and ready to break off before the work is finished. When it will no longer bear the chisel, take it out of the lathe, break it off, and neatly finish with the sharp chisel the central portion, and your first lesson is learnt. There is certainly very little of interest in turning an imperfect cylinder, for it is useless when done, but the alphabet of the art, though not amusing, must be first thoroughly mastered, and the rest will follow in due course. If, however, the work seem unreasonably dull and stupid, the cylinder may be converted into a tool handle, which will be at any rate a useful article, besides affording practice. No special directions are needed in addition to the above, except in respect to the ferrule. This is to be cut off a piece of brass tubing or an old gun barrel, or it may be had at the tool shops ready cut to any size. Begin by turning down the place for this ferrule, taking care not to cut it too small or the ferrule will drop off. Take the piece out of the lathe, and with a mallet hammer on the ferrule. Return it again, taking care to centre it in the old marks, and finish the handle. The brass or iron may be polished with a file for this first attempt.

HOLLOWED WORK.

It is now necessary to speak of hollowing out wood for the purpose of making boxes, cup chucks, &c., and the latter, which may be made in any quantity, and of all sizes, will afford excellent practice in this part of the turner's art. The majority of work of this kind is done rather by scraping or fretting out than by cutting; side tools of the forms of Figs. 51 and 56 being used for the purpose. These however, are specially adapted for ivory and hard woods, the grain of which, being very compact and close, is not torn out in shreds by the action of such tools, as would be the case with softer woods. Where the latter material is used in quantity, as in the manufacture of wooden bowls, hook tools, like Fig. 57, are made use of, which cut on their upper edges. These are exceedingly difficult to use, though the practised hands of those brought up to the art, make them cut with a surprising ease and rapidity--fairly surrounding the lathe with a ceaseless cloud of fine shavings removed in the progress of the work. The difficulty experienced in the use of these tools is not confined to the novice, for the majority of turners accustomed to hard wood often cut a sorry figure in the manipulation of softer material with the aid of the tools in question. The hard and soft wood turners form, in point of fact, two distinct branches of the trade. We have in part anticipated this section, by speaking of the making a wooden chuck when describing the use of the metal chuck with taper screw. We shall, therefore, proceed to describe the best method of turning a plain wooden box with cover, but not screwed; the latter being reserved for more extended notice hereafter. The best material to work upon is sound Turkey boxwood, and care must be taken that it is quite dry and well seasoned, or, after it is worked up with, it may be, great care and trouble, the box will split, or the cover become so loose as to fall off, either fatality being sufficiently vexatious. We may mention, in passing, that hard woods of all descriptions may be had in large or small quantities of Messrs. Fauntleroy[2] and Co., 110, Bunhill-row, Finsbury, or of Jacques and Sons, Covent-garden. Most of the lathe-makers also supply it, especially Holtzapffel and Co., of Charing-cross, but the first-named is a large dealer, wholesale and retail, and his charges are moderate.

[2] Now Messrs. Mundy and Berrie.

Supposing a selection made of size proportionate to that of the intended box, including cover and a tolerable margin for waste and accidents, proceed as before to rough it down between two centres and thus to reduce it to a cylindrical form--there is, however, no occasion to use the chisel at present, as we only need a rough cylinder. Remove this from the lathe, and if you have no brass cup chuck into which you can fit it, proceed to make one out of a piece of beech, ash or, if you have plenty, boxwood. Do not hurry the work, but cut the chuck out neatly, screw and fit it, as previously directed, on the nose of the mandrel. We shall suppose it as yet merely a short neat cylindrical block, quite solid. Place the rest with the tee across the end of the piece of wood, the top edge a little below the centre (by the thickness of the blade of the tool). For the latter select one of the three following--either will answer well--58, 59, 60. With one or the other drill a hole in the centre, keeping the tool quite horizontal across the rest. Enlarge this hole by a left side tool, working from the centre of the piece towards the outside, not taking the whole depth at once, but a quarter or half an inch at a time. You must hollow it out about one inch, and see how nicely you can fit the hollow to the size of the piece you are going to turn. You will, of course, have squared up one or both ends of the latter, which must now be driven tightly into the hollow chuck. If you squared the ends of the cylinder correctly and left also the bottom of your chuck level and true, you will be gratified by seeing the piece run evenly at once.

Fig. 61 shows a section of the chuck with the piece to be turned fitted inside it. Now take the gouge and chisel and reduce the piece to a plain cylinder, and take special care to square up the outer end. This may be done by the aid of a carpenter's chisel held across the rest, like the side-tool. If the end is much out of truth you had better use first the round-ended tool, Fig. 60, but if you have worked carefully from the commencement this will be unnecessary.

To ascertain the correctness of this part, apply a small steel square like Fig. 62, the blade of which slides through the brass part and is clamped by a small screw at the side. We show the method of applying this tool to gauge depth, test right angles, &c., in Figs. 63 and 64. It is a most convenient and necessary instrument, and should be at once provided. Having thus ascertained that the end of your cylinder is at right angles with the side, take the point tool, Fig. 58, or the acute corner of your chisel, and, setting the lathe in motion, mark off the intended depth of the _cover_, as D, C, Fig. 61. (Observe, it is the cover and not the box that first demands attention.) Now proceed to hollow out the cover as you hollowed out the chuck, but with greater care. You must allow in the thickness of the top rather more material than you will eventually require, the thickness of the sides, also, may be a trifle in excess, but take the utmost care to make the inside rectangular, that is, the line _f, g_, perpendicular to g, D. Upon the correctness of this the fit of the cover will depend. This being done and tested as to truth with the square, as before, you may cut off the cover with a parting tool, Fig. 65. This tool is thin, with a cutting edge at the end, and is held edgewise upon the rest. The blade is made rather thicker near the end, so that as the tool penetrates the work it may not bind, but allow the small chips made by it to escape freely. The rest must be removed from its former position and placed parallel to the side of the piece, and the tee at such a height that the latter may, when the tool is held horizontally, point to the axis of the work. The tool should be occasionally withdrawn, and the point, instead of being kept precisely in one position, may be slightly raised and lowered from time to time, describing a small arc. It will soon be ascertained in what position it cuts most easily. There are different sizes of parting tool, some very thin in the blade, for ivory and precious woods, some thicker, for box and less valuable stuff, some with a notched end, forming two points, for soft woods, the action of all being similar to a saw tooth, or, in the last, to two adjacent saw teeth set out to clear themselves in working. Care must be taken that the thin blades do not bend and twist while cutting, especially after the cut has become deep. To avoid this do not hurry the work, but take a little at a time, and be careful to keep the tool with its sides perpendicular to the rest. With these precautions the cover will soon be cut off neatly. If care is not taken to allow for the necessary thickness of the cover, the turner will be mortified by finding that instead of the latter, he has merely cut off a ring, and he will have to expiate his want of judgment by beginning a new cover and making a shallower box. We name this to put him on his guard. Supposing the above work satisfactorily accomplished--the top of the cover, however, being (as will probably be the case) either convex or concave, requiring a little touching up and finishing, it will be necessary to turn down on the solid bit of wood left in the chuck the part A, B (Fig. 66), on which the cover will eventually rest. On no account, however, must this be now turned small enough, it must be left so large as not quite to enter the cover, because if it is now nicely fitted, and the box subsequently hollowed out, the cover is sure to be too slack, the wood shrinking in the process of hollowing out. This shrinking may be accounted for by supposing the rings of woody fibre, the result of yearly growth, naturally elastic, with a tendency to contract, each one, like a series of india-rubber bands, embracing that within it. The central ones being removed by the tool, permit the outer ones to contract, their particles approaching nearer to each other and the structure becoming more dense. This tendency causes those radial cracks so often seen in the ends of pieces of wood sawn from the trunk or limbs of the tree. The outer parts becoming drier than the inner, and prevented by the latter from shrinking, necessarily split, hence, when it can be done, the centre of such pieces is bored out, while the wood is yet full of sap, and the rest is thereby preserved. Where this cannot be done the ends may be covered with glue or resin; or paper may be glued on, to prevent access of air, and thus the drying of the outer portion may be so retarded as only to keep pace with that nearer the centre. The concentric rings thus shrink equally, and no radial splitting takes place.