Part 1
Brat 7 swe ee - A LABORATORY COURSE IN WOOD-TURNING BY MICHAEL JOSEPH GOLDEN, M.E. PROFESSOR OF PRACTICAL MECHANICS, PURDUE UNIVERSITY. ILLUSTRATED NEW YORK -: CINCINNATI «> CHICAGO AMERICAN BOOK COMPANY Copyright, 1897, by Harrer & BROTHERS. All vights reserved. w.P. § AS? 5329 153958 MAY 32 191] ‘G56 INTRODUCTION THE practice of wood-turning 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 opera- tor 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 in- volved 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 wood-turner, some learners may desire to add further practice in some or all of them, and, for the benefit of such, further exercises, involving similar opera- tions, have been added in the form of an appendix. These have drawings, and, where necessary, additional instruc- tions. The operator is urged, however, to perform the regular exercise before attempting the added one. In wood-turning the first essential is that the material being operated on be revolved on an axis with a fair degree ‘T id Hibrary of the University of Wisconsin _-h i Aine ee eee a mw me ~ eee a~eamm da xu f' 6 WOOD-TURNING 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. Fig. § The Fork-centre, shown in Fig. 6, is used in the /ve- spindle to make the work revolve, one end of the wood being driven 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 spzxdle of the ¢azl-stock, and, in common with the come-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 Fig. 6 INTRODUCTION 7 work is of such character that it cannot be held between centres. It is attached to the 4ve-spzndle 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 fast- ened directly to the face- plate, but is held in a wooden disk that is fastened to the faceplate by means of screws. This disk is called a chuck. Faceplates are made in va- rious diameters to suit the size of the work. When they are made more com- plex in character, as with raised rims and attachments in the form of adjusting- screws, they are themselves called chucks. The swng of a lathe 1s twice the distance from the centre of the front end of the “ve-spzndle to the nearest point of the shears. The szze of a lathe is determined by the swing and the length of the shears. The Gouge, shown in Fig. 9, is the Fig. 9 tool of greatest use to the wood-turner. Any piece to be turned Is first rapidly dressed to a rough approximation to the desired form by Fig. 7. Fig. 8 8 WOOD-TURNING 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 nec- essary in order that it may be turned in a small space. . The han- dle 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 finish- ing 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 carpenters chisel, is _——— “skewed” slightly. This —— gives better command of Fig. 11 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 5 INTRODUCTION 9 sometimes ground in such manner that the edges are at right angles with the sides, to avoid the necessity for re- versing them when in use. The Round-nose — —— - Chisel, shown in Fig. 11, ——— rutdlmade QW ——————— =e ing the edge of a carpen- ter’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 cut- ting 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 re- duced. The seventh exercise involves this use of the parting-tool. Its size is determined by the width of its cutting edge. Sharpening Turn- ing - tools. — When sharpening these tools, one is liable to spoil the shape of the cutting edge unless great care is exer- 7 cised, and as the shape Fig. 13 determines the ease with which the cutting edge is guided, an irregular shape will render the management of the tool much more difficult. The operator takes position with the stone turning tow- Fig. 12 IO WOOD -TURNING ards him, and applies the tool in the position shown by the dotted lines in Fig. 13, and at once carefully draws it back to the position shown by the solid ones, with the bevel resting on the stone. The chisel is applied in this manner to avoid the danger of touching the cutting edge against the re- volving stone, and so making it duller than before. face of the stone, as shown in Fig. 14, where Fig. 14 The bevel is held square across the the solid lines show the position when one side 1s being ground, and the dotted lines when the other one. The tool should be moved slowly across the face of the stone, so that the whole of the face may be used, and it must not be allowed to rock, as that would round the bevel. The position of the operator is shown in Fig. 15. The grinding is complete when the ground surface — reaches the cutting edge, and this can readily be seen by holding it so that the light from a win- dow falls across it. If the grinding be continued after this, the extreme end, be- coming thin from the grinding, bends away from the stone, producing what is Fig. 15