This section is from the book "Machines And Tools Employed In The Working Of Sheet Metals", by R. B. Hodgson. Also available from Amazon: Machines and tools employed in the working of sheet metals.
It is necessary for those who are fitting out new factories to have had a reasonably extensive experience, in order that commercial success may result. It is important to emphasise this, particularly as regards automatic machinery, as, partially owing to the"booming"of American automatics, there is a probability that this class of machinery will for some years to come be looked upon as an absolute necessity for the successful working of a manufacturing concern. This may possibly result in a point being reached when a reaction will occur against the use of so many automatics. The subject of rapid and accurate production by special automatic machinery is an important one, but, as in many other subjects, there is more than one standpoint from which the matter may be viewed. The modern manufacturer recognises the value of special machines and tools that may be purchased and successfully used for producing thousands of similar articles, all finished to some particular and definite shape and size. But the question as to the advisability of adopting an automatic machine for the production of any new and special article from sheet metal is one that frequently calls for special judgment and care in the decision, not only to decide upon the methods and number of processes through which the article shall be passed, but to select the most suitable machine for the work. In a cycle, motor car, gun or ammunition works there are sections of the work that can be rapidly and accurately produced by automatics, attended by unskilled labour.
The author trusts that he will not be misunderstood by students, neither does he desire to contend that where considerable quantities of any particular article are required automatic machines should not be used. But there is a great tendency in modern times for automatics to be required for all purposes, and whilst their use should be encouraged, when it is possible to obtain beneficial results, there is a limit to their successful and economical employment.
The capstan lathe is an example of the successful application of a special machine. Its employment for a variety of purposes frequently necessitates modifications in design, so as to ensure of its being equally effective on various classes of work.
As an example of an automatic machine well known in this country we may consider the wire nail, rivet, and panel-pin machine, where a coil of wire is placed upon a swift, the wire being automatically fed through the machine by a grip-feed, whereby thousands of nails, rivets, or panel-pins can be made before the end of the coil is reached, each nail being headed, pointed, then knocked into a box under the machine. Again, there are the tack and tingle machines, where a narrow strip of metal is placed in a feeding tube and automatically turned upon one side, and then the other; at the same time the strip is carried forward, or fed along the tube, by means of a weight fastened to a piece of cord or string. Machines of this kind are generally attended by girls, and the tools are ground and set by the tool maker. The making of an umbrella rib and stretcher is another excellent example of automatic wire machinery, where the rib or stretcher is flattened, pierced both ends, and cropped or cut off automatically at the rate of 78 per minute. The tools for such machines are shown at fig. 1ll; and, returning to sheet metal, button-making from a coil of sheet metal, also the cutting and cupping of blanks as in small arms ammunition, are examples of work being done automatically. Many excellent examples of automatic machines may be seen in the textile industries, in spinning, weaving, and knitting.
The great thing to aim for is suitable machinery and tools having the least possible complication in their design. It is often the case with metal-working machinery that an automatic machine will work well for a short time, producing perfect work, then go suddenly wrong, making it necessary to have an experienced operator to work it, and it is questionable whether there is any great advantage to be gained. One example of automatic machine which may be mentioned as giving no special advantages, would be a machine for automatically drilling four blocks of a cycle chain at one operation. The care and attention required for a perfect result make it doubtful whether there would be any advantage whatever by its adoption.
However, an instance is known where one competent mechanic, with two young assistants, successfully superintended sixty girl operators who were drilling these same steel chain blocks, each operator handling a small single-spindle vertical drilling machine, and fastening the block to be drilled in the small jig shown at figs. 106 and 107. The work in this instance was proved to have been done more accurately and rapidly that could possibly be done in the special automatic machines which were being used in the same works. In cases where a small quantity of an article only is required, or where the demand is likely to be temporary, instances that do not really justify the outlay for a special machine, the mechanic or tool maker must devise some suitable method of utilising what machines and tools he has at hand, to enable the work to be turned out accurately; and providing he has in the tool room or fitting shop, the usual ordinary machine tools, it is not unreasonable to expect him to prepare his temporary tools and jigs. One or two examples will illustrate the principal methods by which their accuracy may be accomplished. Previous to these examples we will indicate the principal machine tools and their uses that one would expect to see in a medium-sized tool room, and follow on by making reference to actual tools that have been made and illustrated in these articles.
The manner of applying the methods must necessarily be left to the mechanic-how best to use and develop them to meet his own particular requirements. If he does this, he will necessarily develop his powers of independent thought, which is so essential to the success of a tool maker who has a limited supply of special appliances at hand from which to execute his work.
 
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