PRACTICAL MECHANICS FOR BOYS TEXT

otherwise he pays for this privilege, and he knows it is incumbent 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 multitude 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 analyzes 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. [Illustration: _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. [Illustration: _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. [Illustration: _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. [Illustration: _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 brass scribes, stocks and dies, screw-plates, taps for bolts, reamers. [Illustration: _Fig. 5. Calipers_] Files for various descriptions, countersinks, frame and hack saws. GRINDING APPARATUS.--Emery wheel, cloth and paper, paper, flour emery, polishing powders, laps and buffs, and polishing sticks. [Illustration: _Fig. 6. Engine Lathe._ _A. Lathe Bed_ _B. Rack Gear_ _C. Live Center_ _D. Dead Center_ _E. Dead Spindle_ _F. Face Plate_ _G. Feed Screw_ _H. Train of Gears_ _I. Head Stock_ _J. Mandrel_ _K. Cone Pulley_ _L. Angle Plate for Tool Holder_ _M. Tool Post_ _N. Tail Stock_ _O. Wheel for Slide Rest Mechanism_ _P. Locking Lever for Tail Stock._] Forge, anvils, tongs, swages, punches, bolt tools, hot and cold chisels, blow-pipe, soldering iron, hard and soft solders, borax, spirits of salts, oil, resin and spelter. To this may be added an endless variety of small bench tools, micrometers, protractors, arbors, collets, box tools and scrapers. [Illustration: _Fig. 7. Center Gage._] LARGE MACHINES.--The list would not be complete without the planer, shaper and milling machine, with their variety of chucks, clamps and other attachments, too numerous to mention. The foregoing show what a wonderful variety of articles are found in a well-equipped shop, all of which can be conveniently used; but to the boy who has only a small amount of money, a workable set is indicated as follows: A small lathe, with an 8-inch swing, can be obtained at a low cost, provided with a countershaft complete. CHUCKS.--With this should go a small chuck, and a face-plate for large work, unless a large chuck can also be acquired. This, with a dozen tools of various sizes, and also small bits for drilling purposes. The lathe will answer all purposes for drilling, but small drilling machines are now furnished at very low figures, and such a machine will take off a great deal of duty from the lathe. [Illustration: _Fig. 8. Pocket Screw and Wire Gage._] As the lathe is of prime importance, never use it for drilling, if you have a driller, as it always has enough work to do for tuning up work. BENCH TOOLS.--Of bench tools, a 3-inch vise, various files, center punch, two hammers, round and A-shaped peons, hack saw, compasses, inside and outside calipers, screw driver, cold chisels, metal square, level, straight edge, bevel square, reamers, small emery wheel and an oil stone, make a fairly good outfit to start with, and these can be added to from time to time. Everything in the machine shop centers about the lathe. It is the king of all tools. The shaper and planer may be most efficient for surfacing, and the milling machine for making grooves and gears, or for general cutting purposes, but the lathe possesses a range of work not possible with either of the other tools, and for that reason should be selected with great care. [Illustration: _Fig. 9. Handy Bench Vise._] SELECTING A LATHE.--The important things about a lathe are the spindle bearings and the ways for the tool-holder. The least play in either will ruin any work. Every other part may be defective, but with solidly built bearing-posts and bearings, your lathe will be effective. For this reason it will not pay to get a cheap tool. Better get a small, 6-inch approved tool of this kind, than a larger cheap article. It may pay with other tools, but with a lathe never. Never do grinding on a lathe. The fine emery, or grinding material, is sure to reach the bearings; it matters not what care is exercised. There is only one remedy for this--overhauling. [Illustration: _Fig. 10.--Combination Square._] COMBINATION SQUARE.--A tool of this kind is most essential, however small. It can be used as a try-square, and has this advantage, that the head can be made to slide along the rule and be clamped at any point. It has a beveling and a leveling device, as well. [Illustration: _Fig. 11.--Uses of the Combination Square._] The combination square provides a means for doing a great variety of work, as it combines the qualities of a rule, square, miter, depth gage, height gage, level and center head. [Illustration: _Fig. 12.--A Quick Adjusting Micrometer._] The full page illustration (Fig. 11) shows some of the uses and the particular manner of holding the tool. MICROMETERS.--Tools of this description are made which will accurately measure work in dimensions of ten-thousandths of an inch up to an inch. The illustration (Fig. 12) shows an approved tool, and this is so constructed that it can instantly be changed and set by merely pressing the end of the plunger as shown. [Illustration: _Fig. 13.--A Universal Bevel Protractor._] PROTRACTORS.--As all angles are not obtainable by the square or bevel, a protractor is a most desirable addition to the stock of tools. As one side of the tool is flat it is convenient for laying on the paper when drafting, as well as for use on the work. The protractor has a graduated disk, and is adjustable so it can be disposed at any angle. [Illustration: _Fig. 14.--Universal Bevel Protractor, showing its uses._] All special tools of this kind are serviceable, and the boy should understand their uses, even though he is not able for the time being to acquire them. To learn how they are applied in daily use is an education in itself. UTILIZING BEVEL PROTRACTOR.--Examine the full-page illustration (Fig. 14), and see how the bevel protractor is utilized to measure the angles of work, whether it is tapering heads or different kinds of nuts, or end and side surfacing, and it will teach an important lesson. [Illustration: _Fig. 15.--Grindstone Truing Device._] TRUING GRINDSTONES.--Devices for truing up grindstones are now made, and the illustration (Fig. 15) shows a very efficient machine for this purpose. It can be applied instantly to the face of the stone, and it works automatically, without interfering with the use of the stone. It is frequently the case that an emery wheel will become glazed, due to its extreme hardness. This is also caused, sometimes, by running it at too high a speed. If the glazing continues after the speed is reduced, it should be ground down an eighth of an inch or so. This will, usually, remedy the defect. [Illustration: _Fig. 16.--Set of Tools and Case._] SETS OF TOOLS.--A cheap and convenient set of precision tools is shown in Fig. 16, which is kept in a neat folding leather case. The set consists of a 6-inch combination square, complete center punch, 6-inch flexible steel rule center gage, 4-inch calipers, 4-inch outside caliper with solid nut, 4-inch inside caliper with solid nut, and a 4-inch divider with a solid nut. [Illustration: _Fig. 17. The Work Bench._] THE WORK BENCH.--This is the mechanic's fort. His capacity for work will depend on its arrangement. To the boy this is particularly interesting, and for his uses it should be made full three inches lower than the standard height. A good plan to judge of the proper height is to measure from the jaws of the vise. The top of the jaw should be on a level with the elbows. Grasp a file with both hands, and hold it as though in the act of filing across the work; then measure up from the floor to the elbows, when they are held in that position. THE PROPER DIMENSIONS.--This plan will give you a sure means of selecting a height that is best adapted for your work. The regulation bench is about 38 inches high, and assuming that the vise projects up about 4 inches more, would bring the top of the jaws about 42 to 44 inches from the floor. It is safe to fix the height of the bench at not less than 34 inches. This should have a drawer, preferably near the right-hand end of the bench. The vise should be at the left side, and the bench in your front should be free of any fixed tools. HOW ARRANGED.--Have a rack above the bench at the rear, for the various tools when not in use, and the rear board of the bench should be elevated above the front planks several inches, on which the various tools can be put, other than those which are suspended on the rack above. The advantage of this is, that a bench will accumulate a quantity of material that the tools can hide in, and there is nothing more annoying than to hunt over a lot of trash to get what is needed. It is necessary to emphasize the necessity of always putting a tool back in its proper place, immediately after using. CHAPTER II HOW TO GRIND AND SHARPEN TOOLS It is singular, that with the immense variety of tools set forth in the preceding chapter, how few, really, require the art of the workman to grind and sharpen. If we take the lathe, the drilling machine, as well as the shaper, planer, milling machine, and all power-driven tools, they are merely mechanism contrived to handle some small, and, apparently, inconsequential tool, which does the work on the material. IMPORTANCE OF THE CUTTING TOOL.--But it is this very fact that makes the preparation of that part of the mechanism so important. Here we have a lathe, weighing a thousand pounds, worth hundreds of dollars, concentrating its entire energies on a little bit, weighing eight ounces, and worth less than a dollar. It may thus readily be seen that it is the little bar of metal from which the small tool is made that needs our care and attention. This is particularly true of the expensive milling machines, where the little saw, if not in perfect order, and not properly set, will not only do improper work, but injure the machine itself. More lathes are ruined from using badly ground tools than from any other cause. In the whole line of tools which the machinist must take care of daily, there is nothing as important as the lathe cutting-tool, and the knowledge which goes with it to use the proper one. Let us simplify the inquiry by considering them under the following headings: 1. The grinder. 2. The grinding angle. THE GRINDER.--The first mistake the novice will make, is to use the tool on the grinder as though it were necessary to grind it down with a few turns of the wheel. Haste is not conducive to proper sharpening. As the wheel is of emery, corundum or other quickly cutting material, and is always run at a high rate of speed, a great heat is evolved, which is materially increased by pressure. Pressure is injurious not so much to the wheel as to the tool itself. The moment a tool becomes heated there is danger of destroying the temper, and the edge, being the thinnest, is the most violently affected. Hence it is desirable always to have a receptacle with water handy, into which the tool can be plunged, during the process of grinding down. CORRECT USE OF GRINDER.--Treat the wheel as though it is a friend, and not an enemy. Take advantage of its entire surface. Whenever you go into a machine shop, look at the emery wheel. If you find it worn in creases, and distorted in its circular outline, you can make up your mind that there is some one there who has poor tools, because it is simply out of the question to grind a tool correctly with such a wheel. [Illustration: _Fig. 18. Hook Tool._] [Illustration: _Fig. 19. Parting Tool._] [Illustration: _Fig. 20. Knife Tool._] [Illustration: _Fig. 21. Right-hand Side Tool._] [Illustration: _Fig. 22. Internal Tool._] [Illustration: _Fig. 23. Left-hand Side Tool._] Coarse wheels are an abomination for tool work. Use the finest kinds devised for the purpose. They will keep in condition longer, are not so liable to wear unevenly, and will always finish off the edge better than the coarse variety. LATHE BITS.--All bits made for lathes are modifications of the foregoing