Lathe work for beginners

On Lathe Work with complete instructions for properly using the various tools, including complete directions for wood and metal Turning, Screw Cutting, Measuring Tools, Wood Turning, Metal Spinning, etc., and instructions for Building Home-made Lathes with their attachments, etc.

The lathe is the master tool. It has taken a great part in the progress of civilization and of all the machines of production, it is the most important.

In the tremendous mass of technical literature published in the United States, there is not one volume devoted wholeheartedly to the lathe from the standpoint of the beginner  the man who desires to learn its uses as an amateur. There are many volumes dealing with large lathes from the industrial viewpoint, but these are more or less useless to the man who knows little or nothing about lathe operation.

In this volume the writer has endeavored to set forth the basic principles of lathe operation and manipulation, in a way that will interest and instruct the layman. The book starts at the very bottom and ends at a point beyond which the average amateur does not care to go.

The author desires to acknowledge his thanks to the following men who assisted in the preparation of the volume. The model naval gun described in Chapter XIII is the work of Mr. F. H. Lubby. The model engineer's lathe described in Chapter XI is the design of Mr. Henry Greenly, an English authority on model engineering. Mr. Joseph Dante, Jr., designed the jig-saw lathe attachment which forms part of Chapter IV. The author also wishes to thank his wife, who not only made stenographic notes of the contents of the entire book, but also typed the manuscript.

There is a multitude of small, low priced lathes on the market. The more expensive machines are, of course, of the precision type and cannot in any way be compared with the inexpensive tools intended for amateur use. In this Chapter the reader is given information that will greatly assist him in making a good choice. Much depends upon the money available for expenditure, and the nature of the work to be done.

In choosing a lathe, the student should first send for the various catalogues of all the reputable manufacturers of small lathes. Each catalogue should be gone over carefully and the individual features of the lathes noted. In this way the prospective purchaser can acquaint himself with the manufacturer's claims without finding it necessary to actually inspect the lathe. An expensive lathe, with all attachments, involves, a considerable outlay of money, and none but an incautious pur- chaser would care to make this investment without first being sure of the quality of the tool he is buying.

For wood turning and light metal work, which do not demand precision, only a simple and inexpensive tool is necessary. A lathe intended entirely for this service is illustrated in Fig. 1. This is a Millers Falls lathe and sells for a very reasonable figure considering the work which comes within its range. Of course, one cannot expect to obtain great accuracy from a machine of this type, but for all ordinary purposes it will be found entirely adequate and capable of rendering good, reliable service.

The lathe shown in Fig. 1 is driven by foot power with an adjustable pedal which can be moved from place to place so that the operator can always use his right foot no matter at what point of the lathe he is working. If the foot-power feature of this lathe is not desirable, it is a very simple matter to drive the machine with a small electric motor. As before stated, light metal work can be done on this lathe. However, it is to be recommended more for wood turning than for metal work.

On a cheap lathe of this nature one cannot expect to find bronze or babbitted bearings as it would be impossible to equip the machine with these desirable features at the low price asked. Neither is the machine provided with a slide rest of any form and therefore all turning must be done with hand tools.

A little wood-turning lathe of more substantial construction, and selling at a much higher figure, is shown in Fig. 2. This is known as the Seneca Falls lathe and contains many features which are not included in the cheaper tool described above. It has a machined bed which is flat on one side and V-shaped on the other. This is a very important consideration and contributes greatly to the accuracy of the machine, since it keeps centers exactly opposite one another. This lathe has a 10-14 inches. The lathe shown may be purchased with either a countershaft for power drive or with a foot-power attachment. This lathe has a cone pulley with four steps by means of which various changes in speed may be brought about.

There are a few general points of construction which the purchaser should have in mind before choosing the lathe he is to use in his shop. The first thing he should look out for is a hollow spindle. This is a very important consideration and contributes greatly to the usefulness and convenience of the tool. Stock can be fed through this hollow spindle, and in the case of making duplicate parts a great saving in time and trouble is made possible. The use of the hollow spindle will be mentioned in a later chapter. Also, the end of the hollow spindle nearest the chuck should be bored out for receiving standard No. 1, Morse taper tools, etc.

The next thing of importance to consider is the bearings. In fact, it can safely be said that a lathe is no better than its bearings. If the bearings are loose and inaccurate, it is impossible to accomplish accurate turning. The more expensive lathes are equipped with either bronze or babbitted bearings. These bearings should be of a cone shape so that it will be possible to take up the wear on the bearings as the lathe grows old. It is only possible to do this with a cone shaped bearing, and for this reason the amateur should try to secure a lathe with this feature. The adjustment is generally brought about by a collar at the left-hand end of the live spindle. It is possible to screw this collar up to adjust the cone bearings.

The lathe bed is an important thing and the accuracy of the machine will depend largely upon it. On smaller lathes of the bench type, the bed is generally made flat with a square slot in the center for guiding the tailstock in alignment with the headstock. On the larger sizes, the bed is usually provided with a V-shaped ridge on either one or both sides. This ridge acts as a guide for both tailstock and carriage, keeping them in the same position in relation to the centers.  

The bed of the lathe should always be machined, that is, it should always be milled by the manufacturer. There are a number of amateur bench lathes on the market with un-machined beds, and they are not worth the metal that is in them.

The tailstock of a lathe should be held by a clamp to the lathe bed, and by loosening this clamp the tailstock should be readily and quickly moved to any position within its range on the bed. The little lathe shown in Fig. 3 has a very useful addition to its tailstock. There are two separate parts on the tailstock body. The top part can be moved on a swivel and thus the back or dead center can be adjusted for taper turning. The top portion of the tailstock can be held at various angles by means of a set screw at the back. Not many lathes possess this simple but useful form of tailstock, and yet, it is a feature well worth noticing.

The lathe shown in Fig. 3 is a Barnes machine of the foot-power type. It is a screw cutting tool. By this is meant that the live spindle can be connected with a train of gears to the "lead screw," which is a long rod containing threads that runs parallel to the lathe body. By means of a splined nut, the carriage of the lathe can be caused to move by this lead screw when it is revolved by the headstock spindle through the train of gears mentioned. In this way it is possible to cut screw threads. All lathes, and especially those of the inexpensive variety, are not provided with the screw cutting fitments. A set of extra gears of various sizes should be provided with screw-cutting lathes, so that different speeds, which correspond to different threads, can be given to the lead screw. The lathe shown in Fig. 3 also has what are known as back gears. This is an addition of great importance which should not be over-looked. With these back gears, it is possible to greatly reduce the speed of the spindle and to multiply the power delivered to the spindle so as to accomplish heavy turning which could not be done at a higher speed.