Practical Mechanics for Boys.

by J. S. Zerbe.

INTRODUCTORY

The American method of teaching the mechanical arts has some disadvantages, as compared with the apprentice system followed in England, and very largely on the continent.

It is too often the case that here a boy or a young man begins work in a machine shop, not for the avowed purpose of learning the trade, but simply as a helper, with no other object in view than to get his weekly wages.

Abroad, the plan is one which, for various reasons, could not be tolerated here. There he is bound for a certain term of years, and with the prime object of teaching him to become an artisan. More often than otherwise he pays for this privilege, and he knows it is inc.u.mbent on him "to make good" right from the start.

He labors under the disadvantage, however, that he has a certain tenure, and in that course he is not pushed forward from one step to the next on account of any merit of his own. His advancement is fixed by the time he has put in at each part of the work, and thus no note is taken of his individuality.

Here the boy rises step after step by virtue of his own qualifications, and we recognize that one boy has the capacity to learn faster than another. If he can learn in one year what it requires three in another to acquire, in order to do it as perfectly, it is an injury to the apt workman to be held back and deterred from making his way upwardly.

It may be urged that the apprentice system instills thoroughness. This may be true; but it also does another thing: It makes the man a mere machine. The true workman is a thinker. He is ever on the alert to find easier, quicker and more efficient means for doing certain work.

What is called "Efficiency" in labor methods, can never obtain in an apprenticeship system for this reason. In a certain operation, where twelve motions are required to do a certain thing, and a minute to perform the twelve operations, a simplified way, necessitating only eight motions, means a difference in saving one-third of the time. The nineteen hundred fewer particular movements in a day's work, being a less strain on the operator, both physically and mentally, to say nothing whatever of the advantages which the proprietor of the shop would gain.

I make this a leading text in the presentation of this book; namely, that individual merit and stimulus is something of such extreme importance that it should be made the keynote for every boy who tries to become a mechanic.

The machinist easily occupies a leading place in the mult.i.tude of trades and occupations. There is hardly an article of use but comes to the market through his hands. His labor is most diverse, and in his employment doing machine work he is called upon to do things which vary widely in their character.

These require special knowledge, particular tools, and more frequently than otherwise, a high order of inventive ability to enable him to accomplish the task.

The boy should be taught, at the outset, that certain things must be learned thoroughly, and that habits in a machine shop can be bad as well as good. When he once becomes accustomed to putting a tool back in its rightful place the moment he is through with it, he has taken a long step toward efficiency.

When he grasps a tool and presents it to the work without turning it over several times, or has acquired the knack of picking up the right tool at the proper place, he is making strides in the direction of becoming a rapid and skilled workman.

These, and many other things of like import, will require our attention throughout the various chapters.

It is not the intention of the book to make every boy who reads and studies it, a machinist; nor have we any desire to present a lot of useful articles as samples of what to make. The object is to show the boy what are the requirements necessary to make him a machinist; how to hold, handle, sharpen and grind the various tools; the proper ones to use for each particular character of work; how the various machines are handled and cared for; the best materials to use; and suggest the numerous things which can be done in a shop which will pave the way for making his work pleasant as well as profitable.

It also a.n.a.lyzes the manner in which the job is laid out; how to set the tools to get the most effective work; and explains what is meant by making a finished piece of workmanship. These things, properly acquired, each must determine in his own mind whether he is adapted to follow up the work.

Over and above all, we shall try to give the boy some stimulus for his work. Unless he takes an interest in what he is doing, he will never become an artisan in the true sense of the word.

Go through the book, and see whether, here and there, you do not get some glimpses of what it means to take a pleasure in doing each particular thing, and you will find in every instance that it is a satisfaction because you have learned to perform it with ease.

I do not know of anything which has done as much to advance the arts and manufactures, during the last century, as the universal desire to improve the form, shape and structure of tools; and the effort to invent new ones. This finds its reflection everywhere in the production of new and improved products.

In this particular I have been led to formulate a homely sentence which expresses the idea: Invention consists in doing an old thing a new way; or a new thing any way.

THE AUTHOR.

CHAPTER I

ON TOOLS GENERALLY

Judging from the favorable comments of educators, on the general arrangement of the subject matter in the work on "Carpentry for Boys," I am disposed to follow that plan in this book in so far as it pertains to tools.

In this field, as in "Carpentry," I do not find any guide which is adapted to teach the boy the fundamentals of mechanics. Writers usually overlook the fact, that as the boy knows nothing whatever about the subject, he could not be expected to know anything about tools.

To describe them gives a start in the education, but it is far short of what is necessary for one in his condition. If he is told that the chisel or bit for a lathe has a diamond point, or is round-nosed, and must be ground at a certain angle, he naturally wants to know, as all boys do, _why_ it should be at that angle.

So in the setting of the tools with relation to the work, the holding and manipulation of the file, of the drill for accurate boring, together with numerous little things, are all taken for granted, and the boy blunders along with the ultimate object in sight, without having the pathway cleared so he may readily reach the goal.

VARIED REQUIREMENTS.--The machinist's trade is one which requires the most varied tools of all occupations, and they are by all odds the most expensive to be found in the entire list of vocations.

[Ill.u.s.tration: _Fig. 1. Bench Vise._]

This arises from the fact that he must work with the most stubborn of all materials. He finds resistance at every step in bringing forth a product.

LIST OF TOOLS.--With a view of familiarizing the boy with this great variety the following list is compiled, from which we shall select the ones essential in the initial equipment of a small shop.

VISES.--One small, good vise is infinitely preferable to two bad ones.

For ordinary work a 3-inch jaw is preferable, and it should be firmly mounted on the bench. So many kinds are now made that it would be a costly thing to purchase one for each special use, therefore the boy will find it profitable to make some attachments for the ordinary vise.

[Ill.u.s.tration: _Fig. 2. Pipe Grip for Vise._]

SWIVEL VISES.--A swivel vise is always a good tool, the cost being not excessive over the ordinary kind. Then a pair of grips for holding pipe, or round material which is to be threaded, can readily be made.

The drawing (Fig. 2) shows a serviceable pair of grips, made to fit the jaws of a vise, and will be acceptable in much of the work. Then, the vise should be provided with copper caps for the jaws to be used when making up articles which would otherwise be injured by the jaws.

[Ill.u.s.tration: _Fig. 3. Swivel Vise._]

Let us get a comprehensive view of the different kinds of tools necessary in a fully equipped shop.

PARTS OF LATHE.--The first thing of importance is the lathe, and of these there is quite a variety, and among the accompaniments are the slide rest, mandrel, back gear, division plate, angle plate, cone plate and various chucks.

There must also be change wheels, studs and quadrant plates, self-acting feed for surfacing and cross slide, and clamping nuts.

Drilling machines, both hand and power, hand and ratchet braces and breast-drill stocks.

[Ill.u.s.tration: _Fig. 4--Speed Lathe._]

CHISELS.--Chisels of various kinds, for chipping and cross-cutting; round-nosed, centering, set punches, tommies and drifts.

Back, tee and centering square; bevels, spirit level, inside and outside calipers, straight edges, rules and surface plates.

Gages for boring, scribing blocks, steel and bra.s.s scribes, stocks and dies, screw-plates, taps for bolts, reamers.

[Ill.u.s.tration: _Fig. 5. Calipers_]