Читать книгу Practical Mechanics for Boys - James Slough Zerbe - Страница 6
ON TOOLS GENERALLY
ОглавлениеJudging 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 obp. 8ject 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.
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 familiarizingp. 9 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.
Fig. 2. Pipe Grip for Vise. ToList
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 willp. 10 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.
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
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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.
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
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Gages for boring, scribing blocks, steel and brass scribes, stocks and dies, screw-plates, taps for bolts, reamers.
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
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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.
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,p. 15 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.
Fig. 8. Pocket Screw and Wire Gage.ToList
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 aboutp. 16 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.
Fig. 9. Handy Bench Vise.ToList
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 bep. 17 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.
Fig. 10.—Combination Square.ToList
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.
p. 18 Fig. 11.—Uses of the Combination Square. ToList
The combination square provides a means forp. 19 doing a great variety of work, as it combines the qualities of a rule, square, miter, depth gage, height gage, level and center head.
Fig. 12.—A Quick Adjusting Micrometer.ToList
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 dip. 20mensions 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.
Fig. 13.—A Universal Bevel Protractor.ToList
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.
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Fig. 14.—Universal Bevel Protractor, showing its uses.ToList
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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.
Fig. 15.—Grindstone Truing Device.ToList
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 facep. 23 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.
Fig. 16.—Set of Tools and Case.ToList
Sets of Tools.—A cheap and convenient set ofp. 24 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.
Fig. 17. The Work Bench.ToList
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 thoughp. 25 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
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