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Modern Shop Practice V2| by Howard Monroe Raymond



A General Reference Work on Foundry Work, Forging, Pattern Making, Mechanical And Machine Drawing, Etc.

TitleModern Shop Practice V2
AuthorHoward Monroe Raymond
PublisherAmerican Technical Society
Year1916
Copyright1916, American Technical Society
AmazonModern Shop Practice

By Editor-in-Chief Howard Monroe Raymond, B. S., Dean, Armour Institute Of Technology

Assisted by Corps of Shop Experts, Designers And Enginleers.

Illustrated with over Two Thousand Engravings.

Six Volumes

-Foundry Work. Part I. Molding Practice
Introductory Foundry work is the name applied to that branch of engineering which deals with melting metal and pouring it in. liquid form into sand molds to shape it into castings of all descriptio...
-Divisions Of Iron Molding
Main Branches There are four main branches in gray iron molding: (1) green-sand work; (2) core work; (3) dry-sand molding; and (4) loam work. Green-Sand Molding The cheapest quickest method o...
-Molding Equipment. Materials
Before taking up the making of molds, let us consider briefly the materials used, where they are obtained, and what is their particular service in the mold. Also we shall describe the principal tools ...
-Sand Quality
All sands are formed by the breaking up of rocks due to the action of natural forces, such as frost, wind, rain, and the action of water. Fragments of rocks on the mountain sides, broken off by act...
-Foundry Facing Function
Foundry facing is the term given to materials applied to or mixed with the sand which comes in contact with the melted metal. The object is to give a smooth surface to the casting. They accomplish thi...
-Miscellaneous Materials. Fire Clay
Fire clay comes from the same source that sand does. It is almost pure oxide of alumina, which is separated out from the sand by a combination of the chemical action of the waters of the streams. Fire...
-Molding Tools. Flasks
Under this heading only the hand tools and equipment used by the molder in putting up his mold are described. The mechanical appliances for reducing labor are described in a later section. To use s...
-Molding Tools. Flasks. Continued
Rammers Rammers are used for evenly and quickly packing the sand in the flask. One end is in the shape of a dull wedge, -called the peen end, the other is round and flat called the butt end. Of the...
-Molding Processes. Principles Of Green-Sand Molding
Good Work There are certain principles underlying iron molding which hold good in all classes of founding, and a practical understanding of these principles is necessary for good work in any line. ...
-Molding Processes. Principles Of Green-Sand Molding. Part 2
Use Of Chaplets Chaplets should be used to support parts of cores which cannot be entirely secured by their prints which are held in the sand of the mold. In Fig. 20 are shown the three principal f...
-Molding Processes. Principles Of Green-Sand Molding. Part 3
Skimming Gate When particularly clean castings of medium weight are required, some form of skimming gate should be used. Fig. 24 illustrates one of several practical forms. They all depend for thei...
-Molding Processes. Principles Of Green-Sand Molding. Part 4
Pressure-Head Example Applying the first law, if we have two columns of liquid iron connected at the bottom, they would just balance each other. For convenience we shall leave out of our calculatio...
-Typical Molding Problems
General Precautions When starting to ram a flask, see that the sands to be used are well cut through and properly tempered. Select a flask large enough to hold the pattern and have at least 2 inche...
-Typical Molding Problems. Part 2
Strengthening Against Pressure There are two methods used to strengthen these molds against the casting pressure. One is to use an iron band which will just slip inside of the flask before the mold...
-Typical Molding Problems. Part 3
Split-Pattern Molds So far the patterns used have been made in one piece, but a flat joint is the most economical for the molder, when many castings are required. Generally such pieces as bushings,...
-Typical Molding Problems. Part 4
Dust On Parting Sand Place the drag in position and ram it up in the usual way, only using facing sand next the joint and pattern. Place six long gaggers to strengthen the sand which forms the insi...
-Molding Processes. Principles Of Core Work
Reference has been made in the first part of this article, under Divisions of Iron Molding, to the general difference between core work and green-sand work. This, and the section on Sands, the reader ...
-Molding Processes. Principles Of Core Work. Part 2
These conditions are obtained by using a coarse free sand and a binder. To give additional strength when necessary, iron wire or rods, or cast-iron core arbors are bedded in the core. These serve the ...
-Molding Processes. Principles Of Core Work. Part 3
Proper Seating Wherever possible, core boxes should be made with their widest opening exposed for packing the core, and designed so that the core may rest, while being baked, on the flat surface fo...
-Molding Processes. Principles Of Core Work. Part 4
Setting Cores Cylindrical Cores. Plain Fitting Among the following examples showing typical ways of setting and securing cores in molds and of connecting vents, the bolt-hole core, shown at A, Fig....
-Expediency In Use Green-Sand Cores
Many times the jobbing foundry may find it expedient, where patterns and core boxes are furnished by the customer, to make certain changes which will reduce the cost of production; for, unhappily, the...
-Duplicating Castings
Practical Requisites In Hand Molding Devising methods for increasing production and decreasing its cost is one of the important problems of modern engineering in the foundry as well as elsewhere. I...
-Use Of Molding Machines. Types of Molding Machines
Although there are many styles of molding machines on the market, these may be classified under four general types as follows: stripping-plate machines; squeezers; roll overs; and jar or jolt-ramming ...
-Use Of Molding Machines. Types of Molding Machines. Continued
Power Operation The above-mentioned types show only hand machines which have been in general use for a considerable period of time, but the last decade has shown a wonderful change in this branch o...
-Dry-Sand Work
Characteristic Features This branch of molding becomes a separate trade in shops where the work is done continually. The dry-sand molder must use the same precautions as the green-sand molder in se...
-Loam Molding
Skill Required The loam molder requires the greatest all-around skill in the whole range of foundry work. He must know all the tricks of the core room and dry-sand shop, and most of those in green ...
-Loam Molding. Part 2. Materials
Brick Common red brick is best for making loam molds, Figs. 120 to 123. It should be free from glaze and have a uniform texture, so that the pieces will break clean when it is necessary to fit them...
-Loam Molding. Part 3
Bedding Cover Plate In case a cover plate must be bedded down against a flat surface, as in the example just mentioned, or must take the impression of an irregular surface on the top of a mold or p...
-Loam Molding. Part 4
Intricate Mold As an example of a complex piece of loam work, let us consider the molding of a modern marine-engine cylinder, as shown in section, Fig. 123. The example given is that of a double-po...
-Foundry Work. Part II. Casting Operations. Melting
General Characteristics The subject of melting the metal which is to be poured into molds is one of the most important considerations in the foundry. It is also one which has received much attentio...
-Cupola Furnace
Furnace Parts Foundry iron is melted in direct contact with the fuel in a cupola furnace. The name was derived from the resemblance of the furnace to the cupola formerly very common on the top of d...
-Cupola Furnace. Part 2
Gage The cupola should have a blast gage attached to the wind box to measure the pressure of air which enters the tuyeres. The pressure should be sufficient to force the air into the middle of the ...
-Cupola Furnace. Part 3
(9) Put on the blast when ready for the metal, and leave the tap hole open. Bott up when the metal begins to run freely - generally about 7 minutes after blast is on. Bott clay should be mixed with...
-Cupola Mixture Requirements
By the term cupola mixture is meant the proportioning of the various pig irons and the scrap that make up cupola charges, with the object of obtaining definite physical and chemical properties in the ...
-Cupola Mixture Requirements. Continued
To calculate for any result, we must first know the analysis of the irons to be used in making the charge. We shall consider silicon as the guide. In keeping track of results, the proportion of sil...
-Supplementary Operations. Sand Mixing
When a mold is poured, the intense heat of the iron burns out those properties in the sand which give it its bond, making it necessary that a certain proportion of new sand shall be mixed with the hea...
-Steel Work
Present Development This class of work has developed within the last few years, and, beginning with the heavier parts of marine and engine construction, it is now crowding the field of drop forging...
-Steel Molds
Facing Mixtures To withstand the high heat, pure silica sand is used as the basis of the facing mixtures for steel molds. Pure quartz or silica rock is quarried, and reduced to sand form through a ...
-Steel Castings
Running A Heat. Open-Hearth Melting The melting of steel is a science by itself, and cannot be dealt with adequately in an article of this character. Only a very brief description of the process is...
-Malleable Practice
Development It is believed that early attempts to soften hard castings by reheating them, and the collection and publication of the results of these operations in 1722, by Reaumur, which led to the...
-Testing Malleable Cast Iron
Methods There are two general ways for testing malleable cast iron: (1) by so-called shop tests; and (2) by laboratory tests of bars cast from every heat and annealed with the castings. Shop Tes...
-Malleable Production Processes
Preparing Molds. Patterns One of the most important departments of the malleable works is the pattern shop. Malleable castings are comparatively light when considered in connection with general gra...
-Malleable Production Processes. Part 2
Air-Furnace Melting The number of furnaces of this type far exceeds all others. In the issue of the Foundry Magazine for February, 1910, the number of the different types of furnaces engaged in the...
-Malleable Production Processes. Part 3
Ferrosilicon This material is carried in stock, either as a 0.50 or 0.75 per cent alloy for use in the ladle, or as a 14 to 20 per cent pig for use in the furnace. In choosing metals for the...
-Brass Work Alloys
Distinctions Cast iron, cast steel, and malleable iron, which we have previously considered, are three forms of the same metal - iron. The difference in their physical characteristics is due solely...
-Brass Work Alloys. Mixtures. General Proportions
The percentages given in Table VI are for convenience in comparison and for figuring large heats. The beginner, however, will generally melt but 1 or 2 pigs of copper at one time. These he will weigh ...
-Brass Work Production
Molding Materials Natural molding sands are used for brass work. They are usually finer than sands used in iron work, because brass parts are generally small and often have fine detail which must b...
-Brass Work Production. Part 2
Examples Of Work To illustrate more clearly some of the typical methods of brass work, let our first example be a thin flat plate with decoration in low relief on one side. Place the pattern fac...
-Brass Work Production. Part 3
Gas Or Oil Furnace With the development of natural-gas and crude-oil burners for commercial heating, several good furnaces have been designed in which a large quantity of metal can be melted at one...
-Shop Management. Plant Arrangement
Governing Factors The success of a foundry depends upon the ability of its managers to promptly turn out castings which meet the requirements demanded of them, at the lowest possible cost commensur...
-Typical Foundry Management
General Plan To briefly illustrate some of the points to be brought out, let us consider the plan of the shop shown in Fig. 186, and its sectional elevation shown in Fig. 187. Building The bu...
-Foundry Performance Labor
Division The division of labor in a foundry is briefly as follows: Superintendent The superintendent is responsible for the operation of the foundry as a whole. He hires the men and oversees ...
-Safety in Foundry
Accident Prevention While it may be an impossibility to wholly prevent accidents in and about the foundry, much has been accomplished in that line. Mechanical safeguards are now in pretty general u...
-Foundry Physical Results
Checking The methods of mixing iron by analysis have been previously dealt with, but these mixtures must be checked by physical tests on the resulting castings. Two systems of checking are now in m...
-Foundry Practical Data
Using Percentage (1) To find the percentage of any number when the rate per cent is given: Multiply the number by the rate per cent and set the decimal point two places to the left. Example: Fin...
-Forging. Part I. Mechanical Details. Materials And Equipment
Forging Materials Forging in general treats of the hammering, working, or forming of heated metals. The materials upon which forging or blacksmithing is done, are wrought iron and steel. As explain...
-Heating Apparatus For Forging
Forges While forges or fires are of many shapes and sizes, the principles of their construction remain the same. An ordinary blacksmith forge is a fireplace in the bottom of which there is a tuyere...
-Reverberatory
A reverberatory, or air furnace, is a furnace in which ore, metal, or other material is , exposed to the action of flame, but not to the contact of burning fuel. The flame passes over a bridge and the...
-Forge Shop Common Tools
Hammers Several kinds of hammers are used in a forge shop. The commonest shape is the ball peen shown at A, Fig. 8. Other kinds are the straight peen and cross peen illustrated at B and C. A square...
-Machine Tools. Manufacturing Requirement
The manufacturing shop differs very essentially from the jobbing shop. In the lattershop very few forgings are made at the same time exactly alike, while in manufacturing, each forging is generally du...
-Forcing Operations Smith Welding
Nature Of Process If a piece of steel or iron is heated, the metal becomes softer as the temperature is raised. Finally a heat is reached, called the welding heat, at which the metal is so soft tha...
-Forcing Operations Smith Welding. Part 2
Lap Welding This is the common weld used for joining flat bars together. The ends to be welded are scarfed or shaped as shown in Fig. 27. In preparing, the ends of the pieces to be welded should be...
-Forcing Operations Smith Welding. Part 3
Flat Or Washer Ring This is a ring made by bending fiat iron edgeways. The ends of the stock are first upset but not scarfed, except for careful work, the ring bent into shape, and the corners trim...
-Simple Bend Forcing
Fundamental Forging Operations. Shaping After the metal has been heated it is shaped with the hammer. This shaping may consist of drawing, upsetting, or bending. In drawing a bar of iron it is made...
-Calculation Of Stock For Bent Shapes. Mathematical Calculation. Angles
It is always convenient and frequently necessary to know the exact amount of stock required to make a given piece of work. There are four general methods used for determining this. The first and most ...
-Measurement By String Or Wire. Scrolls And Irregular Shapes
Difficult shapes may be measured by either of two methods. The commoner way is to lay the scroll or shape off full size and measure the length by laying on this full-sized drawing a string or thin pie...
-Bend Types. Ring And Eye Bending
In making a ring or an eye, the first step of course is to calculate the amount of stock required. In making ordinary rings 4 or 5 inches in diameter, the stock should be heated for about half its len...
-Bend With Square-Forged Corner. Upsetting
Brackets and other forgings are frequently made with the outside corner square and sharp, as shown at C, Fig. 61, and, of the two ways of doing this, one method is to use the size of stock required fo...
-Forming Shoulders
The shoulder where the round stock joins the square should be forged in the manner indicated in Fig. 63. The bar is laid across the anvil with the point where the shoulder is wished lying directly on ...
-Eye Bolts
Eye bolts are made by two general methods, being either solid or welded. The solid eye bolt is much stronger. A solid eye bolt, or forged eye, as it is sometimes called, may be started in the general ...
-Chain Hooks
These are made in a variety of shapes and with solid or welded eyes, the general method of making the eyes being exactly as described before under Eye Bolts. A common shape is shown in Fig. 69. The st...
-Hoisting Hooks. Sizes
A widely accepted shape for hooks of this character used on cranes is shown in Fig. 71. The shape and formulas for the dimensions are given by Henry R. Towne in his: Table I. Sizes Of Hoisting Hook...
-Bolts. Upset-Head Types
Of the two methods of making bolts, either by upsetting or by welding the heads, the first method is more common on small bolts and machine made bolts. The welded head is more commonly used for heavy ...
-Welded-Head Type
Bolts of this type are made by welding a ring of square iron around the end of the shank to form the head. The ring is generally bent up on the end of a bar as shown at A, Fig. 75, but not welded. ...
-Forging Tongs
Common flat-jawed tongs, such as are used for holding light work, may be made as follows: The stock should be about 1 inch by 3/4 inch. The first step should be to work the stock down over the edge of...
-Forging Ladles
Ladles similar to the one shown in Fig. 83, may be made from two pieces welded together, one forming the handle, the other the bowl, or as sometimes is done, the handle may be riveted on. A piece of f...
-Medium Forged Work. Calculation Of Stock. Stock Changed In Shape
The calculations made previously for stock, were for stock which was simply bent into shape, the original section or size of the stockremaining unaltered. There is a large variety of work where the sh...
-Weight Of Forging
To find the weight of any forging the volume may first be found in cubic inches and this multiplied by .2779, the weight of wrought iron per cubic inch. If the forging be made of steel, the figures .2...
-Forging Finish
Many forgings are machined or finished after leaving the forge shop. The drawings are always made to represent the finished work and therefore give the finished dimensions, and it is necessary when th...
-Standard Large Types. Crank Shafts
There are several methods of forging crank shafts. The one more commonly used is the commercial method, as described in detail below. When forgings were mostly made of wrought iron, the cranks were we...
-Multiple-Throw Cranks
When a crank shaft has more than one crank or crank pin, it is spoken of as a multiple-throw crank; a double-throw crank is a crank shaft with two cranks; a three-throw or triple-throw, one with three...
-Weldless Rings
Rings and eyes forged solid without any welds may be made in the general manner described below. As an example, suppose;t be required to make a ring such as illustrated in Fig. 101. It is necessary, o...
-Lever With Boss
Taking as an example the forging shown in Fig. 103, the following description will serve for many forgings of the same general shape. There are two general ways of making work of this character. One i...
-Knuckles
One example of a very numerous class of forgings is shown in Fig. 107. This is the shape used for what are known as marine ends of connecting rods, knuckle joints on valve rods, and various other piec...
-Wrenches. S-Wrench
A simple tool that is frequently called for is the S-wrench. This wrench is usually made with a gap at each end suited for nuts of different sizes. It is shown complete in Fig. 114. The jaws at the en...
-Ladle Shank
The ladle shank shown in Fig. 118 may be made in several ways. The ring may be welded up of flat stock and a round handle welded on with a T-weld, or square stock may be taken, worked out, and split a...
-Molder's Trowel
The molder's trowel illustrated in Fig. 121 is a sample of a large class of forgings, having a wide thin face with a comparatively small thin stem forged at one end. The stock used for the trowel woul...
-Forging. Part II. Forging Operations. Tool-Steel Work
Tool Steel Although not strictly true technically, for ordinary purposes tool steel may be considered simply a combination of iron and carbon. The more common grade contains perhaps 1 per cent of c...
-Forging. Part II. Forging Operations. Tool-Steel Work. Continued
Round-Nose And Thread Tools These tools are practically alike, excepting for a slight difference in the way the ends are ground. The general shape is shown in Fig. 128. When hardening, the tools sh...
-Hammer Forging
When making a hammer the stock should be taken large enough to make the largest part of the hammer without any upsetting. As a general rule the hammer is forged on the end of a bar and is finished as ...
-Miscellaneous Forging Processes. Shrinking
When iron is heated it expands, and upon being cooled it contracts to about its original size. This property is utilized in doing what is known as shrinking. Fig. 144 shows a collar shrunk on a shaft....
-Brazing
When two pieces of iron or steel are welded together, they are joined by making the pieces so hot that the particles of one piece will stick to those of the other, no medium being used to join them. I...
-Bending Cast Iron
It is sometimes necessary to straighten a casting which has become warped or twisted. Cast iron may be twisted or bent to quite an extent if worked cautiously. The bending may generally be done at abo...
-Die Forging
Pieces are sometimes shaped between formed steel dies where many are to be made exactly alike. An example of this sort of work is the eye bolt, Fig. 151. Round stock is used and is first shaped like A...
-Heavy Forging
Steam Hammer An ordinary form of steam hammer is shown in Fig. 154. Its essential parts are an inverted steam cylinder, to whose piston rod the hammer head is attached, and the frame for carrying t...
-Hammer Chisels
The common shape for hot chisels for use under the steam hammer is given in Fig. 156. The handle and blade are sometimes made from one piece of tool steel. Sometimes the blade is made of tool steel an...
-Tools. Swages
The tools used for steam-hammer work are generally very simple. Swages for finishing work up to 3 or 4 inches in diameter are commonly made in the shape shown in Fig. 161. The handle is made in the sh...
-Examples Of Work. Crank Shaft
The crank shaft shown in Figs. 91 and 92 is quite a common example of steam-hammer work. The stock is first worked as illustrated in Fig. 167, the cuts being on each side of the crank cheek, and a spe...
-Drop Forging
Development Drop forgings were made first about 60 years ago, and from the necessarily crude methods which were first employed, the art of forging has developed into one of the largest branches of ...
-Heat Treatment
Relation To Steel Development The development of highspeed and of high-grade carbon steel has resulted in the development of scientific heat treatment. Where the process is applied, those cases in ...
-Heating For Forging
Uniform Heating Essential In the first place, when steel is to be heated in a blacksmith forge, a clean deep fire is necessary for uniform results. If the fire is shallow, the steel oxidizes. The t...
-Annealing
General Process Steel is annealed for two distinct reasons: (1) to soften the metal for machining; and (2) to relieve the strains in the steel caused by hammering or by bending in the mill or the f...
-Hardening
Purpose Hardening generally is understood to mean the heating of a piece of steel to a certain temperature and plunging it into a bath of some kind for the purpose of cooling it. While this definit...
-Quenching Tank Essentials
The main point to be considered in a quenching bath as mentioned before, is to keep it at a uniform temperature so that the successive pieces quenched will be subjected to the same heat. The next cons...
-Carbonizing. Problem Of Casehardening
During the last few years, when the universal aim of the designer and manufacturer has been directed to the highest efficiency of the product, a problem of a peculiar nature is sometimes met. For a...
-Use Of Crucible. Packing
The parts to be casehardened should be placed in the crucible in such a way that none of them may come in contact with it, for otherwise the result would be soft spots; there should be a space of at l...
-Cyanide Hardening. Potassium-Cyanide Bath
Some hardeners prefer cyanide of potassium to lead for heating cutting tools, dies, etc. It is a white transparent salt which melts at a fairly low temperature, and should be carefully used as it is a...
-Tool Work. General Laws For Hardening
Because of the many grades of steel now made containing various alloys, it is impossible to give any set rules for hardening as compared with those used at the time when strictly straight carbon tool ...
-Measuring And Testing Instruments. Pyrometers
All up-to-date hardening rooms now are equipped with pyrometers in order to insure uniformity of the heat in the furnaces, and also uniform results in the hardened products. There are various types...
-Steel Tempering
Essentials Of Process To temper steel is to return it to a state of molecular equilibrium at atmospheric temperature by relieving any strains in the metal which have been caused by sudden quenching...
-Tempering High-Speed Steel
Tools of large size and for hard usage, such as lathe and planer tools, do not require to be tempered, and should be cooled in thin oil such as lard or kerosene oil. In using kerosene oil care should ...
-Review Questions On The Subject Of Foundry Work #2
On The Subject Of Foundry Work. Part I 1. Why is facing used on a mold? 2. What is the practical way to test the temper of molding sand? 3. What are chaplets? 4. What three forms of gases ...
-Review Questions On The Subject Of Forging #2
On The Subject Of Forging. Part I 1. Make a sketch and show all dimensions of a hoisting hook for a load of 2,000 pounds. 2. What three materials are commonly used in forge work? 3. In making...
-Pattern Making. Part I. Practical Requirements
Characteristics Pattern making dates back to the time when the first article was made from molten metal for the use of man. The pattern must precede the making of its metal counterpart, and is ther...
-Pattern Making Working Medium. Woods Used
Ideal Material As patterns are subjected to more or less rough usage, and are alternately wet and dry, it follows that the ideal material is one whose hardness is such that it will withstand the we...
-Pattern Making Tool Equipment
Distinction In Use While many of the tools used by the pattern maker are identical with those used by the carpenter and cabinetmaker, yet the conditions which govern the construction of patterns fo...
-Hand Cutting Tools
Rip Saw Hand saws are of two kinds - rip, and crosscut. The former, as the name indicates, is for cutting with the grain, or lengthwise of the board to be sawed. In Fig. 10 is illustrated a rip saw...
-Crosscut Saw
The crosscut saw really severs or cuts the fibers of the wood twice, as shown at a in Fig. 12, the intervening projections being loosened and carried out as dust by the thrust of the saw, producing a ...
-Back Saw
The back saw illustrated in Fig. 17 is used as a bench saw for light or fine work, and for fitting and dovetailing. Saws of this type are made from 8 to 14 inches in length, the 10- and 12-inch being ...
-Compass Saw
As the work of the compass saw, Fig. 19, is both with and across the grain of the wood, the best form of tooth is that shown in Fig. 20, having more pitch, and slightly less bevel, than the crosscut s...
-Iron Plane
The modern iron plane, illustrated in Fig. 21, can now be bought in a great variety of sizes and styles. These planes, with their true and unchanging faces, and their simple appliances for setting and...
-Common Types Of Planes
Jack Plane Of iron planes, the most important is the No. 5 jack plane, 14 inches long, and having a cutter 2.inches in width, as illustrated in Fig. 24. When the pattern lumber has first been rough...
-Special Planes. Rabbet Plane
Among the special planes used by the pattern maker, the rabbet plane, llustrated in Fig. 29, is the most important. The face of this plane is always flat and at right angles to the sides. It is used i...
-Round And Hollow Planes
These planes are illustrated in Figs. 32 and 33. They are made of different curvatures, and a set of assorted sizes, especially the rounds, are almost indispensable to the pattern maker for finishing ...
-Spokeshave
The spokeshave is used by the pattern maker for shaping and rounding out small curves, either convex or concave, which cannot be reached with the circular plane. It can be found in a great variety of ...
-Chisels
While carpenters' chisels are made in several styles, they may be divided into two general classes: socket-handled chisels; and firmer or paring chisels. The former are illustrated in Fig. 41, and are...
-Gouges
The paring gouges used in pattern making are ground or beveled on the inside, as shown in Fig. 46. These gouges are made in regular, middle, and flat sweeps. They are indispensable for working out cor...
-Boring Tools. Brace
Among the necessary tools are the brace and an assortment of boring bits. The most desirable style of brace is the ratchet brace, illustrated in Fig. 49. The convenience of the ratchet will soon be ap...
-Measuring Tools. Squares
The best try-squares are now made with blades graduated, and from 2 inches to 12 inches in length. Several sizes of the fixed-blade type, Fig. 54, are needed, as in many cases the blade must be short ...
-Bevels
The bevel illustrated in Fig. 58, with the clamping screw in the end of the handle, is the most accurate and the most easily adjusted style of this indispensable tool. The blades are made from 6 to 12...
-Shrinkage Rules
For all ordinary measurements, a 2-foot folding standard rule. Fig. 60, will be sufficient, but this rule must not be used for laying out or for working patterns, or any part of a pattern or core box,...
-Marking Tools. Marking Gage
The marking gage is used for drawing a line at a given distance from, and parallel to, the already trued and jointed surface or edge of a board or piece of wood that is being marked to dimensions. ...
-Dividers
The ordinary woodworker's dividers can be bought in many forms, the most common being the screw-adjusting wing dividers shown in Fig. 63. This form is reliable, and is easily adjusted to the required ...
-Trammel
The trammel is used when the distance between the points to be reached is too great for the ordinary dividers. The trammel points are clamped to a beam of sufficient length to enable them to be set th...
-Caliper
Calipers, like dividers, are made in many different forms with and without screw adjustment. Fig. 69 illustrates the screw-adjusting wing calipers for outside measurements, and Fig. 70 shows the firm-...
-Miscellaneous Small Tools. Forcing Tools. Hammer And Mallet
There remain to be described a few tools, which, while necessary, are so common as hardly to require either illustration or description. Among these are the hammer, the best form of which for the patt...
-Screwdriver And Awls
Of the screwdriver, illustrated in Fig. 75, at least two or three sizes will be found necessary. Fig. 75. Ordinary Screwdriver. The scratch awl, Fig. 76 - although but little e...
-Pliers And Clamps
Side-cutting pliers, such as are illustrated in Fig. 78, will be found convenient not only for cutting off wire and brads, but for removing small brads and for holding small pieces while being worked ...
-Abrading Tools. Wood Files. Oil Stones And Slips
The half-round cabinet file and half-round cabinet rasp, shown in Fig. 81, enter largely into the work of the pattern maker, and should be bought in sizes each of 6 inches, 8 inches, and 10 inches. La...
-Grindstone
Second in importance to a good oil stone is the grindstone, power driven if possible. It should not be too close-grained. A rapid cutting stone, even if moderately coarse, is greatly to be preferred, ...
-Machine Tools. Turning Equipment. Pattern-Maker's Lathe
Of all power-driven machines, the most indispensable to the pattern maker is the wood-turning lathe. In a small shop where small patterns only are made, a 14-inch or a 16-inch speed lathe, such as is ...
-Skew Chisel
As the turning gouge - being curved - can be used only as a roughing-down tool or for turning out hollows, and cannot be used for finishing, the skew chisel, one size of which is shown in Fig. 92, is ...
-Scraping Tools
While the skew chisel works with great rapidity and does smooth and very satisfactory work in all kinds of ornamental turning, the dimensions obtained with this tool are not so accurate for pattern wo...
-Sawing Machines. Circular Saw
As a time-saving and labor-saving machine a good circular-saw bench is necessary in every well-equipped pattern shop, and is unsurpassed in capacity and in the variety of work for which it may be used...
-Planers
Because of the fact that pattern lumber can be bought already dressed to any required thickness, a planing machine is not found in every pattern shop. The ordinary surface planer, however, will not ta...
-Trimmers
Among the many labor-saving tools of late years, there is perhaps none more popular and none more indispensable in a pattern shop than the universal wood trimmer. It will cut any end or angle within t...
-Allowances In Construction Molding Practice
General Molding As has already been said, it is necessary that the pattern maker should have some knowledge of molding in order that he may construct his patterns so that they can easily be removed...
-Coping Out For Solid Patterns. Simple Cylinder
In molding the above cylinder it is not necessary that the pattern should be parted - made in two halves - as shown in Fig. 106. Patterns for small work, and even for large castings, are often made in...
-Molding Difficult Patterns
Use of Green-Sand Ring. In the small sheave pulley, Fig. 120, we have an example of a casting the construction of the pattern for which, so as to make it easily removable from the sand, may give some ...
-Loose-Piece Patterns
It is frequently the case that parts of the pattern will overhang so that the pattern cannot be removed from the sand in any direction, even if parted. In such cases the overhanging parts are fastened...
-Use Of Drawings
Construction Conditions As already explained, the pattern maker must understand working drawings in order to construct patterns from them directly. These drawings are usually made to a scale much l...
-Pattern Making. Part II. Construction Of Patterns. Simple Types
Conditions Of Procedure Whenever the building of a pattern is consigned to the pattern maker, a detailed sketch or drawing of the completed casting should be furnished; also information regarding t...
-Influence Of Molding Method. One-Piece Patterns. Green-Sand Coring
The simplest patterns are those which are made in one piece, and which require no coring, although the castings themselves may be hollow. Deciding the method of molding indicates the way in which the ...
-Finishing. Shellacking
Having completed the pattern and its core box, the surface of the wood must be covered with some material which will render it hard, smooth, and impervious to the moisture in the sand, and at the same...
-Split Patterns. Conditions
The second casting to which attention is called, is the brass bearing represented in Fig. 150, which is to be finished all over. On examining the drawing, first with regard to removing the pattern fro...
-Fastening Process
Gluing As the use of glue enters largely into the construction of all patterns, some instruction as to its selection and the manner of using is necessary. When building up patterns, the connections...
-Clamping. Use Of Hand Screws
The hand screws, illustrated in Fig. 79, Part I, Pattern Making, enter so largely into all gluing for pattern work that some description of their construction and the manner of using is necessary here...
-Built-Up Patterns. Sheave Pulley. Green-Sand Ring Coring
For practical reasons, the first method of molding - for green-sand core, or, in this case, ring - the 6-inch sheave pulley shown in Fig. 159 would ordinarily not be used. The expense of molding would...
-Built-Up Patterns. Sheave Pulley. Part 2
A disk or chuck of wood 5 1/2 inches in diameter is now screwed to the iron faceplate, or the screw chuck, and turned off true on the face, with a projection 1/8 inch high which will fit into the rece...
-Built-Up Patterns. Sheave Pulley. Green-Sand Ring Coring. Part 3
Building Rim Prepare stock 1/2 inch thick, and saw to a length slightly greater than the chord for five segments. Stack and nail three of these pieces together, and lay out one segment, as shown in...
-Countershaft Pulley. Construction For Special Size
The making of patterns for special pulleys enters largely into the [work of many pattern shops. In these patterns the rims are built up of. segments 3/8 inch to 1/2 inch in thickness. To illustrate th...
-Rim Construction. Use Of Chuck
For building the rim, a wooden chuck 20 1/2 inches in diameter will be necessary. A board 7/8 inch in thickness and having a bar 8 inches wide and of the same thickness, well screwed to the back with ...
-Standard Pulleys. Method Of Construction
It is the same with the pulley pattern as with most other patterns - the number of castings required and the complexity of the demands determine the method of molding. Several methods of molding a pul...
-Lifting Plate. Use
In molding patterns made as above, the molder will require a lifting plate. The lifting plate is anchored to the top of the cope block and will lift the center of the mold without any liability of its...
-Rapping Plate. Use
When a pattern is imbedded in the sand, the latter is closely compressed all about it, and slightly adheres. Fig. 182. Rapping and Draw Plate. The molder is therefore in the ha...
-Standard Core Prints. Economy In Use
While standard dimensions of the cylindrical core prints are not universally used, many large corporations operating pattern shops and foundries have adopted a standard, and the economy of this practi...
-Large Cored Pulley. Molding Method
For the larger sizes of cast pulleys, including spur gears, rope sheaves, and balance pulleys, the wooden-arm and metal-rim patterns are impractical. In Fig. 185 are shown the dimensions of a single s...
-Flat-Back Patterns. Solid Engine Crank. Construction
The heavy engine-crank pattern illustrated by Fig. 192 should be built of five layers of stock, gluing heart sides and bark sides of each piece together, as shown in Fig. 193. Dress the stock true on ...
-Disk Crank Construction
Fig. 194 illustrates a finished cast-iron disk crank for an engine, of 12-inch stroke. This crank is finished on the face, on the outer edge, and on the end of the hub. It is bored out 3 1/4 inches to...
-Fillet
Usage The fillets spoken of in connection with Fig. 195 are used in all except the most simple patterns. They consist of a small quarter curve varying in size from 1/8-inch radius upward, depending...
-Economical Construction. Coring To Obviate Machining. Example Of Faceplate
It is sometimes advisable to use cores even if it is quite possible to construct the pattern so that it would core its own holes. This is the case where it is desired that the faces of the casting and...
-Examples Of Simplified Work. T-Pipe Connection
Many patterns which at first may seem to be quite formidable, will, after a little study, resolve themselves into a few very simple parts, nearly all the work for which may be done in the lathe. Of th...
-Large Cylindrical Work
The patterns for the larger pipes or columns are to be glued up, as shown in Fig. 224, and, for turning, the two halves are held together by means of lathe dogs such as shown in Fig. 206. The treatmen...
-Intricate Coring
Globe Valve Globe Construction The globe valve, shown in section in Fig. 229, is a good illustration of a pattern in which, while the outside may be very simple, the inside is intricate and require...
-Engine Cylinder. Type Of Pattern
The slide-valve engine is built in a great variety of forms. Fig. 244 represents a sectional view of the cylin-der of a very common type. At e, Fig. 245, we have a cross-section through the steam ches...
-Core Boxes. Cylinder
The main core box for the cylinder is made in the same way as has been already described for Fig. 227. Steam Chest The steam-chest core box is shown in Fig. 249, in which P is a side view, one s...
-Gear Wheels
Accurate Teeth Required In this special class of pattern work, the greatest accuracy and care must be taken, not only in building up the rim of the wheel, but in fitting and placing on the rim the ...
-Patterned Teeth. Form. Fastening Methods
As the form of the tooth used by the draftsman will play no part in the construction of the pattern, we think it would be out of place here to enter into a discussion of the relative merits of the sin...
-Forming Teeth. Placing Blocks
The face should be glue sized to prepare it for the blocks which are to form the teeth of the gear. After sizing and removing the raised grain of the wood, the periphery of the wheel must be spaced fo...
-Bevel Gears. Built-Up Construction
Patterns for bevel and miter gears are built as illustrated at a and b, Fig. 261. The segments are to overlap as shown, which is not only a saving of stock, but also saves time which would be required...
-Columns
Patterns Cast-iron columns are often ornamented or fluted as shown in the half section of a fluted column in Fig. 268. In all such cases the body of the pattern is made octagonal, as shown by the o...
-Part III. Complicated Pattern Construction. Hand-Molded And Machine-Molded Examples. Hand-Molded Hydraulic Turbine
Conditions This class of work requires a very clear conception of the principles of pattern making. The working drawings are for the completed casting as usual, Fig. 272, while the several core box...
-Guide Ring Coring. Guide Vanes
The illustrations and descriptions are for the guide-ring casting; the equipment for the rotor-ring casting being very similar to that for the guide ring except in dimensions. Fig.273 is a plan view o...
-Vane Core Box. Flanged Sides
Preliminary to making the durable iron core box. Fig. 275, prepare stock for the flanges for the wooden core box 2/8 inch thick, obtaining the form and dimensions from the double-shrink zinc template,...
-Machine-Molding Practice
Adaptation To Production The adaptation of patterns to the present-day demands on the foundry for large output of duplicate castings makes it imperative to so arrange the equipment that the largest...
-Use Of Pattern Plate. Bearing-Cap Pattern. Shrinkage
For the use of a pattern plate with the pattern for the ring-oiling ball-and-socket shaft-hanger bearing cap, Figs. 287 and 288, the process of constructing the wooden pattern is identical with that f...
-Stripping Draw-Plate Machine
Flange-Coupling Pattern for Hand Molding. In Fig. 296 is illustrated one half of a flange coupling such as is commonly used on mill shafting. Fig. 297 illustrates a radial section view of a pattern fo...
-Parallel Drawing Device. Typical Deep-Draw Work
When the pattern, like the spur gear illustrated in Fig. 302, has considerable depth of draw d, there is liability of one end of the draw board being lifted ahead of the other, which will cant the pat...
-Stripping-Plate. Hand-Rammed Molding Machine
Hand-Molding Conditions Before taking up the design and construction of the parts required to adapt the patterns to machine molding, the conditions presented by the hand-molded patterns may be brie...
-Stripping-Plate. Hand-Rammed Molding Machine. Continued
Use Of Stool Whenever it becomes necessary to strip an internal surface of a pattern, as illustrated in the socket or bousing for the hardwood bearing used in the holder frame. Fig. 308, some means...
-Green-Sand Coring. Expanding Pattern
Characteristic Usage The bearing-cap casting seen in Fig. 341 was first produced with a hand-molded pattern, using a heel core to mold the square hole in the upright position shown at d. This heel ...
-Double-Draw Stripping-Plate Machine. Typical Feature
The feature of this arrangement used for molding the jaw clutch, Fig. 359, is that the pattern is used as a stripping plate for the hub and the clutch jaws. It was specified that there was to be no dr...
-Green-Sand Core Box. Suitability
Such castings as short lengths of pipe, and elbow and T-pipe fittings of reasonable diameter lend themselves readily to this method of molding. It would not be economy to equip for this method if a ve...
-Hollow Roll Cast On Steel Shaft
Split-Pattern Method Construction In the first of the two methods of making the cast-iron roll, Fig. 372, to be considered, the steel shaft is placed in the mold, and, having been spotted with a dr...
-Stripping-Ring Method. Characteristics
The following description will show a second method for making the cast roll. This arrangement produces clean and accurate castings, the machine-finish allowance being 3/8 inch. Fig. 376 illustrates t...
-Flask Construction. Cheek
The pattern for the flask will be molded by striking a green-sand core, lagging this to obtain the thickness, and molding the lower flange with a dry-sand core, and the upper flange with loose segment...
-Mechanical Drawing. Part I
The subject of mechanical drawing is of great interest and importance to all mechanics and engineers. Drawing is a method of showing graphically the minute details of machinery; it is the language by ...
-Mechanical Drawing Instruments And Materials
Drawing Paper In selecting drawing paper, the first thing to be considered is the kind of paper most suitable for the proposed work. For shop drawings, a manila paper is frequently used on account ...
-Mechanical Drawing Triangles
Triangles are made of various substances such as wood, rubber, celluloid, and steel. Wooden triangles are cheap but are likely to warp out of shape; rubber triangles are frequently used, and are, in g...
-Mechanical Drawing Compasses
Compasses are used for drawing circles and arcs of circles. The cheaper class of instruments are made of brass, but they are unsatisfactory on account of the odor and the tendency to tarnish. The best...
-Mechanical Drawing Dividers
Dividers, which are similar to compasses, are used to lay off distances on the drawing, either from a scale or from other parts of the drawing, Fig. 25. They are also used for dividing a line into equ...
-Bow Pen And Bow Pencil
Ordinary large compasses are too heavy and the leverage of the long leg is too great to allow small circles to be drawn accurately. For this reason the bow compasses, Figs. 26 and 27, should be used o...
-Drawing Scales
The scales used for obtaining measurements on drawings are made in several forms, the most convenient being the flat, with beveled edges, and the triangular. The scale is usually graduated for a dista...
-Protractor
The protractor, an instrument used for laying off and measuring angles, is made of steel, brass, horn, or paper. When made of metal the central portion is cut out, Fig. 31, so that the draftsman may s...
-Irregular Curve
One of the conveniences of a draftsman's outfit is the French or irregular curve, which is used for drawing curves other than arcs of circles, with either pencil or line pen. This instrument, which is...
-Part I. Lettering
No mechanical drawing is finished unless all headings, titles, and dimensions are lettered in plain, neat type. Many drawings are accurate, well-planned, and finely executed but do not present a good ...
-Preliminary Line Problems
To lay out the paper for the plates of this work, place a sheet, A B G F, Fig. 38, on the drawing board 2 or 3 inches from the left-hand edge, called the working edge. If placed near the left-hand edg...
-Inking
To ink a drawing well requires great care and some experience. The student should not attempt to ink in his work until he can make a clear-cut, straight line with ease. It is well to practice inking i...
-Preliminary Line Problems. Plate I. Penciling
To draw Plate I,* take a sheet of drawing paper at least 11 inches by 15 inches and fasten it to the drawing board as already explained. Find the center of the sheet and draw fine pencil lines to repr...
-Preliminary Line Problems. Plate II. Penciling
The horizontal and vertical center lines and the border lines for Plate II are laid out in the same manner as were those of Plate I. To draw the squares for the six figures, proceed as follows: Mea...
-Preliminary Line Problems. Plate III. Penciling
Plate III should be laid out in the same manner as Plate II, that is, for size and border lines. In laying out the sixteen rectangles, however, the space between the center lines and rectangles must i...
-Appendix. How To Hold Drawing Instruments
Position Of Hand And Instruments Important To the student who is just starting out with his drawing work, the position in which he holds his instruments and the free and easy posture of his hands a...
-Donts In Drafting Work
Don't fold a drawing. Don't stick the dividers into the drawing board. Don't use the dividers as picks. Don't use the scale to rule lines. Don't fail to clean the table, board, and instrum...
-Examination Plates
Drawing Plates I to III inclusive constitute the Examination for this Instruction Paper. The student should draw these Plates in ink and send them to the School for correction and criticism. The ve...
-Geometrical Definitions. Lines
A point is used for marking position; it has neither length, breadth, nor thickness. A line has length only; it is produced by the motion of a point. A straight line or right line is one that ha...
-Geometrical Definitions. Angles
An angle is the measure of the difference in direction of two lines. The lines are called sides, and the point of meeting, the vertex. The size of an angle is independent of the length of the lines. ...
-Geometrical Definitions. Polygons
A polygon is a plane figure bounded by straight lines. The boundary lines are called the sides and the sum of the sides is called the perimeter. Polygons are classified according to the number of s...
-Geometrical Definitions. Circles
A circle is a plane figure bounded by a curved line called the circumference, every point of which is equally distant from a point within called the center, Fig. 58. A diameter of a circle is a str...
-Measurement Of Angles
To measure an angle, take any convenient radius and describe an arc with the center at the vertex of the angle. The portion of the arc included between the sides of the angle is the measure of the ang...
-Geometrical Definitions. Polyhedrons
A polyhedron is a solid bounded by planes. The bounding planed are called faces and their intersections are called edges. The intersections of the edges are called vertices. A polyhedron having fou...
-Geometrical Definitions. Cylinders
A cylinder is a solid having as bases two equal parallel surfaces bounded by curved lines, and as its lateral face the continuous surface generated by a straight line connecting the bases and moving a...
-Geometrical Definitions. Cones
A cone is a solid bounded by a conical surface and a plane which cuts the conical surface. It may be considered as a pyramid with an infinite number of sides, Fig. 80. The conical surface is called...
-Geometrical Definitions. Spheres
A sphere is a solid bounded by a curved surface, every point of which is equally distant from a point within called the center. The diameter is a straight line drawn through the center and having i...
-Geometrical Definitions. Conic Sections
If a plane intersects a cone at various angles with the base the geometrical figures thus formed are called conic sections. A plane perpendicular to the base passing through the vertex of a right circ...
-Geometrical Definitions. Odontoidal Curves. Cycloidal Curves. Cycloid
The cycloid is a curve generated by a point on the circumference of a circle which rolls on a straight line tangent to the circle, as shown at the left, Fig. 93. The rolling circle is called the de...
-Geometrical Problems. Plate IV
The problems given in Plates IV to VIII inclusive have been chosen because of their particular bearing on the work of the mechanical draftsman. They should be solved with great care, as the principles...
-Problem 1. How To Bisect A Given Straight Line
Draw the horizontal straight line A C about 3 inches long. With the extremity A as a center and any convenient radius - about 2 inches - describe arcs above and below the line A C. With the other extr...
-Problem 2. How To Construct An Angle Equal To A Given Angle
Draw the line 0 C about 2 inches long and the line 0 A of about the same length. The angle formed by these lines may be any convenient size - about 45 degrees is suitable. This angle A O C is the give...
-Problems 3 And 4. How To Draw Through A Given Point A Line Parallel To A Given Line
First Method Draw the straight line A C about 3 1/2 inches long and assume the point P about 1 1/2 inches above A C. Through the point P draw an oblique line F E forming any convenient angle - abou...
-Problems 5 And 6. How To Draw A Perpendicular To A Line From A Point In The Line
First Method. When The Point Is Near The Middle Of The Line Draw the line A C about 3 1/2 inches long and assume the point P near the middle of the line. With P as a center and any convenient radiu...
-Geometrical Problems. Plate V. How To Draw A Perperidicular To A Line From A Point Without The Line
Penciling In laying out the border lines and center lines follow the directions given for Plate IV. Draw the dot and dash lines in the same manner, as there are to be six problems on this plate. ...
-Problems 8 And 9. How To Bisect A Given Angle
First Method. When The Sides Intersect Draw the lines O C and O A - about 3 inches long - forming any angle of 45 to 60 degrees. With 0 as a center and any convenient radius - about 2 inches - draw...
-Problem 10. How To Divide A Line Into Any Number Of Equal Parts
Let A C - about 3 3/4 inches long - be a given line. Suppose it is desired to divide it into 7 equal parts. First draw the line A J at least 4 inches long, forming any convenient angle with A C. On A ...
-Problem 11. How To Construct A Triangle Having Given The Three Sides
Draw the three sides, A C, 2 3/4 inches long; E F, 1 15/16 inches long; and M N, 2 3/16 inches long. Draw R S equal in length to A C. With R as a center and a radius equal to E F describe an arc. W...
-Problem 12. How To Construct A Triangle Having Given One Side And The Two Adjacent Angles
Draw the line M N 3 1/4 inches long and draw two angles A O D and E F G about 30 degrees and 60 degrees respectively. Draw R S equal in length to M N and with R as a vertex and RS as one side const...
-Geometrical Problems. Plate VI. How To Describe An Arc Or Circumference Through Three Given Points Not In The Same Straight Line
Penciling Lay out this plate in the same manner as the preceding plates. Problem 13. How To Describe An Arc Or Circumference Through Three Given Points Not In The Same Straight Line Locate th...
-Problem 14. How To Inscribe A Circle In A Given Triangle
Draw the triangle L M N of any convenient size. M N may be made 3 1/4 inches, L M, 2 3/4 inches, and L N, 3 1/2 inches. Bisect the angles M L N and L M N by the method used in Problem 8. The bisectors...
-Problem 15. How To Inscribe A Regular Pentagon In A Given Circle
With O as a center and a radius of about l 1/2 inches, describe the given circle. With the T-square and triangles draw the center lines A C and E F perpendicular to each other and passing through 0. B...
-Problem 16. How To Inscribe A Regular Hexagon In A Given Circle
With 0 as a center and a radius of 1 3/8 inches draw the given circle. With the T-square draw the diameter A D. With D as a center, and a radius equal to 0 D, describe arcs cutting the circumference a...
-Problem 17. How To Draw A Line Tangent To A Circle At A Given Point On The Circumference
With 0 as a center and a radius of about 1 1/4 inches draw the given circle. Assume some point P on the circumference and join the point P with the center 0. By the method given in Problem 6, Plate IV...
-Problem 18. How To Draw A Line Tangent To A Circle From A Point Outside The Circle
With O as a center and a radius of about 1 inch draw the given circle. Assume P some point outside of the circle about 2 1/2 inches from the center. Draw a straight line passing through P and O. Bisec...
-Geometrical Problems. Plate VII. How To Draw An Ellipse When The Axes Are Given
Penciling Lay out this plate in the same manner as the preceding plates. Problems 19 And 20. How To Draw An Ellipse When The Axes Are Given First Method Draw the lines L M and C D about 3 ...
-Problem 22. How To Draw A Spiral Of One Turn In A Circle
Draw a circle with the center at O and a radius of 1 1/2 inches. Locate twelve points, 1/8 inch apart on the radius 0 A and draw circles through these points. With the 30-degree triangle, draw radii O...
-Problem 23. How To Draw A Parabola When The Abscissa And Ordinate Are Given
Draw the straight line A B - about three inches long - as the axis, or abscissa of the parabola. At A and B draw the lines EF and C D perpendicular to A B, and with the T-square draw E C and F D, 1 1/...
-Problem 24. How To Draw A Hyperbola When The Abscissa E X, The Ordinate A E, And The Diameter X Y Are Given
* See Page 16, Mechanical Drawing, Part I. Draw E F about 3 inches long and mark the point X, 1 inch from E and the point Y, 1 inch from X. With the triangle and T-square, draw the rectangles A B D...
-Geometrical Problems. Plate VIII. How To Construct A Cycloid When The Diameter Of The Generating Circle Is Given
Penciling In laying out Plate VIII, draw the border lines and horizontal and vertical center lines as in previous plates, dividing the plate into four spaces. Problem 25. How To Construct A Cycl...
-Problem 26. How To Construct An Epicycloid When The Diameter Of The Generating Circle And The Diameter Of The Director Circle Are Given
The epicycloid and the hypocycloid may be drawn in the same manner as the cycloid if arcs of circles are used in place of the horizontal lines. With 0 as a center and a radius of 3/4 inch describe a c...
-Problem 27. How To Draw An Hypocycloid When The Diameter Of The Generating Circle And The Radius Of The Director Circle Are Given
With C as a center and a radius of 4 inches describe the arc E F, which is the arc of the director circle. Now with the same center and a radius of 3 1/4 inches, describe the arc A B, which is the lin...
-Problem 28. How To Draw The Involute Of A Circle When The Diameter Of The Base Circle Is Known
With the point 0 as a center and a radius of 1 inch, describe the base circle. Divide the circle into any number of equal parts - 16, for instance - and draw radii to the points of division. At the po...
-Part III. Projections. Orthographic Projection
Definitions. Projection The word projection means to throw forward. In mechanical drawing, the significance is to throw forward in straight lines. Projection really means, therefore, either the act...
-Part III. Projections. Orthographic Projection. Continued
It is readily seen that from this one projection, drawing, or view, no idea of the depth of the box is given, although the width and height are correctly shown. A top, or plan, view must now be made t...
-Practical Problems In Projection
1. Square Bar Fig. 106 represents a square bar. A is the front elevation, and shows the length and width of the bar, but not the thickness. There must then be another view. B is the plan, and shows...
-True Length Of Lines
Principles If a line is parallel to a plane, its projection on that plane will be equal in length to the line itself, as represented in Fig. 115. If a line is perpendicular to a plane, its projecti...
-Representation Of Objects
Rectangular Prism Or Block In Fig. 122 there is represented a rectangular prism or block, whose length is twice its width. The elevation shows its height. As the block is placed at an angle, three ...
-Rotating And Inclining Of Objects
Method Of Rotating Object The natural way to place an object to be shown by projections would be in the simplest position; that is, with an edge or face parallel to either the horizontal or vertica...
-Illustrative Examples. 1. Construct Plan And Elevation Of A Regular Hexagonal Pyramid
It is evident that two distinct geometrical views are necessary to convey a complete idea of the form of the object; an elevation to represent the sides of the body, and to express its height; and a p...
-Intersections
If one surface meets another at some angle, an intersection is produced. Either surface may be plane, or curved. If both are plane, the intersection is a straight line; if one is curved, the intersect...
-Intersections. Continued
Planes With Cones Or Cylinders Sections cut by a plane from a cone have already been defined as conic sections. These sections may be any of the following: two straight lines, circle, ellipse, para...
-Development Of Surfaces
General Details Of Process A surface may be considered as formed by the motion of a line. Any length of line moved side-wise in any direction will form a surface, of a width equal to the length of ...
-Isometric Projection
Isometric Of A Cube In orthographic projection an object has been represented by two or more projections; another system, called isometrical drawing, is often used to show in one view the three dim...
-Characteristics Of Various Isometrics. Cube With Inscribed Circles
Fig. 156 shows a cube with circles inscribed in the top and two side faces. The isometric of a circle is an ellipse, the exact construction of which would necessitate finding a number of points; for t...
-Oblique Projection
Comparison With Isometric Projection In oblique projection, as in isometric, the end sought for is the same - a more or less complete representation, in one view, of any object. Oblique projection ...
-Line Shading
Object Of Line Shading In finely finished drawings it is frequently desirable to make the various parts more readily seen by showing the graduations of light and shade on the curved surfaces. This ...
-Part III. Lettering
Types Of Lettering In the early part of this course, the inclined Gothic letter was described, and the alphabet given. The Roman, Gothic, and block letters are perhaps the most used for titles. The...
-Principles Of Orthographic Projection
Plates IX to XV, inclusive, are to be drawn by the student for practice in applying the principles of orthographic projection, intersections and developments, isometric and oblique projection, and for...
-Principles Of Orthographic Projection. Plate X
The figures on the reproduced Plate X in the back of this book give the outline of the work that is to be completed by the student. The dimensions given on this plate are to be used in working out the...
-Principles Of Orthographic Projection. Plate XII. Developments
On this plate draw the developments of a truncated octagonal prism, and of a truncated pyramid having a square base. The arrangement on the plate is left to the student; but it is suggested that the t...
-Review Questions On The Subject Of Pattern Making #2
On The Subject Of Pattern Making Part I 1. What are some of the causes of warping in lumber? 2a. When is metal used for patterns? 2b. Why is metal better than wood? 3. Why should plenty of oil b...
-Machine Drawing. Part I. Working Drawings
Methods And Conventions In Mechanical Drawing, Parts I, II, and III, the common drafting instruments and materials are described, and hints given regarding their use; the fundamental geometrical pr...
-Crosshatching
To make a sectional view, the object is supposed to be cut open, and all the material removed between the cutting plane and the eye. This makes visible the hidden portion, and the drawing, therefore, ...
-Shade Lines
The theoretical principles for shade lines, already given in Mechanical Drawing, Part III, cannot be exactly applied to working machine drawings without involving an excessive amount of time and labor...
-Machine Drawing. Dimensions
It is easy to spoil an otherwise good drawing by loose and careless methods of putting on dimensions. Systematic and careful effort must constantly be used to make every dimension upon a drawing absol...
-Machine Drawing. Complete Instructions And Specifications
It is naturally difficult for the student to determine what constitutes complete instructions to the workman, and this knowledge can only be fully acquired by experience, both in drawing room and sh...
-Specifications For Screw Threads
Exact drawings for the helix forming the thread of a screw are shown in Machine Drawing, Part II. These not only are difficult to draw, but they consume considerable time to produce accurately, theref...
-Specifications For Screw Threads. Continued
Threads In Sectional Pieces Figs. 18, 19, and 20 illustrate the common method of representing threads when they occur in pieces which are drawn in cross section. The front half of the piece is supp...
-Specifications For Bolts And Nuts
A bolt is a cylindrical bar upset at one end to form a head and having a screw thread cut at the other end. A nut is a hollow piece of metal in which a screw thread has been cut. A right-hand bo...
-Square Head And Nut
Fig. 27 shows three views of a square head or nut with chamfer corresponding to that on the hexagonal head in Fig. 23; and Fig. 28 shows the square head or nut chamfered to correspond to Fig. 26. Refe...
-Specifications For Pipes And Pipe Threads. Kinds Of Pipe
The various kinds of pipe in common use are made to standard sizes, and as the draftsman very often comes in contact with piping we will consider it briefly. The kinds commonly used are wrought-iron o...
-Scale Drawings
When the object which is to be drawn is not so large but that it can be easily shown actual size (or full size as it is called) on a sheet of paper of convenient dimensions, it is good practice to dra...
-General System For Shop Drawings. Sketches
The principles of detail drawings having been thoroughly discussed in the preceding pages, the general system to be followed in preparing shop drawings for the workman's use will now be outlined and i...
-Second Step - Pencil Drawing
After the sketches are made, the next step is the making of the pencil drawing from the sketches, accurately to scale. The size of the plate on which the drawing is to be made is usually fixed by some...
-Third Step - Tracing
Having finished the pencil drawing, the next step is the inking. In some offices the pencil drawing is made on a thin, tough paper, called bond paper, and the inking is done over the pencil drawing, i...
-Fourth Step - Blue Printing
The tracing, of course, cannot be sent into the shop for the workmen to use, as it would soon become soiled and in time destroyed, so that it is necessary to have some cheap and rapid means of making ...
-Illustrative Machine Drawings. Crank - Rough Sketch
The following illustrative drawings show the common practice in making working drawings, which it would be tedious and difficult to formulate as rules to guide the student. By a careful study of the i...
-Bell Crank
Fig. 33 shows a bell crank fastened to its shaft by means of a set screw, the same general features being noted in this as in the preceding figure. A further point is the method of expressing the dist...
-Rocker Arm And Pin
Fig. 34 shows the detail of a rocker arm and pin, such as are frequently found in connection with the valve gear of a steam engine. This is a case where it is just as clear to detail two pieces togeth...
-Flange Coupling
Fig. 36 shows a flange coupling such as would be used to connect up a line shaft in a shop, or any heavy machinery shafting. The detail construction of this is most clearly shown by making the drawing...
-Clamp Eye
Fig. 37 shows a piece designed to receive a threaded rod at one end and to clamp rigidly to a shaft by means of a bolt at the other. This detail, simple as it appears, is awkward to make, on account o...
-Connecting Rod
Fig. 38 shows the connecting rod for a small steam engine. This piece calls for little comment. The outlines of the crank pin and cross-head pin are shown in dot-and-dash circles, and the relation of ...
-Gear With Split Hub. Conventional Drawing
Fig. 39 shows a gear with a split hub, the bolts through the hub being for the purpose of tightly clamping same to the shaft. This is an illustration of the conventional method of showing a gear with ...
-Spur Gear
Fig. 40 shows the detail of a spur gear with a T-shape arm. The gear drives through fitted bolts in the flange about the hub. Two or three teeth are dotted in, to show their dimensions, which are acco...
-Cylinder Head
Fig. 44 shows the cylinder head of a steam engine. Although in the drawing the entire circle is shown, it would have been just as clear if only one-half had been shown, similar to the manner of showin...
-Crane Drum Grooved For Chain
Fig. 47 shows a crane drum, grooved for chain, and carrying its driving gear and shaft. This is a very good illustration of the economy of grouping parts together, instead of detailing them separately...
-Bearing Stand With Cap And Boxes Removed
Fig. 49 shows a bearing stand with the cap and boxes removed. There is little of special note to discuss in regard to this, beyond calling attention to the general nature and type of the piece illustr...
-Sample Letters
Fig. 50 shows a sample sheet of plain letters, such as are particularly applicable to working drawings. They are especially devised for easy, quick, and uniform strokes. Each draftsman has a character...
-Machine Drawing. Part II. Mechanism Drawing
Study Of Mechanisms In Machine Drawing, Part I, working shop drawings have been analyzed in detail, systematic processes for making them have been outlined, and numerous illustrations given and tho...
-Helix
Development Of Helix Since most coil springs and all screw threads depend upon a curve known as a helix, it will be necessary to know what a helix is, and how it can be drawn, before taking up the ...
-Helical Springs. Accurate Representation Of Springs
If, instead of winding a line around a cylinder in the form of a helix, as shown in the preceding figures, we wind a piece of spring wire, we shall get a helical spring. Fig. 56 is the drawing of a...
-Screw Threads
Screw And Nut If we cut a groove around a cylinder in the form of a helix, we shall have what is called a screw thread, the thread being formed by the material which is left between the successive ...
-Conventional Representations Of Screw Threads
The student should understand the drawing of the threads, as previously explained; and every draftsman should be able to draw the true projection of a thread if he should have occasion to do so. It is...
-Machine Drawing. Cams
Mechanical Action A cam is an applied form of the ordinary wedge. The simple wedge is used to split apart the piece into which it enters, or to pry up heavy weights. It does not automatically repea...
-Practical Examples In Laying Out Cams
Statement Of Problems From the principles just stated, the uniform course of procedure in laying out a cam is as follows: 1. Draw the follower in several positions in its path. 2. Draw cam ra...
-Example 1. Pointed Follower With Path Intersecting Cam Center
1. Follower Positions The length of travel 06, Fig. 79, is supposed to be known, being fixed by some requirement of the machine to which the cam is to be applied. This distance, for a uniform motio...
-Example 2. Pointed Follower With Path Not Intersecting Cam Center
1. Follower Positions The follower positions, Fig. 80, are chosen and drawn precisely as in Fig. 79; in this case, however, the path of the follower does not intersect the center of the cam, but, i...
-Example 3. Roll Follower With Path Intersecting Cam Center
1. Follower Positions In Fig. 81, the case is identical with that of Fig. 79, except that the shape of the follower has been changed to the more practical form of a roll, which can turn about a pin...
-Example 4. Roll Follower With Path Not Intersecting Cam Center
1. Follower Positions The follower positions in Fig. 82 are chosen precisely as in Fig. 81, and the subdivisions of the path of the follower similarly made. This case corresponds with that of Fig. ...
-Example 5. Roll Follower Mounted On Oscillating Arm
1. Follower Positions In Fig. 83 the follower is a roll, as before; but instead of traveling in a straight line, it is made to travel along the arc of a circle, being carried on the end of an arm O...
-Example 6. Pointed Follower Mounted On Oscillating Arm
In Fig. 84 the follower roll has been abandoned, and the original pointed follower substituted. The motion of the follower point, however, instead of being in a straight line, is in the arc of a circl...
-Example 7. Flat Follower With Path Perpendicular To Working Face
1. Follower Positions In this example, Fig. 85, is introduced a follower with a flat surface, its path being perpendicular to its working face. The length of its path 06 is the same as before, and ...
-Example 8. Flat Follower Mounted On Oscillating Arm
1. Follower Positions In this example, Fig. 86, a flat-faced follower is carried by an oscillating arm similar to the roll in Fig. 83. The length of travel 06 is divided into six equal parts, as in...
-Design Of Complicated Cams
It should be especially noted, that in all the cases of cams thus far studied, the methods of procedure are absolutely identical. In the more complicated cases of cams which follow, and others which m...
-Practical Example Of Complex Motion Cam
For the purpose of illustrating these principles, suppose it is required to design a plate cam, Fig. 90, such that the follower rises from point A to e, with harmonic motion, while the cam rotates thr...
-Translation Cams
Rotating plate cams, like those thus far considered, are most commonly met with in practice. A straight-line, reciprocating motion of a plate, however, may be made to produce similar follower movement...
-Cylindrical Cams. Development Of Cylinder Cams
Suppose that the outline of the translation cam as developed in Fig. 91 be wrapped around a cylinder whose circumference is exactly equal to Dx, and that the lines represent a spiral groove cut into t...
-Belting
Cams and gears transmit positive motion from the driver to the follower by direct contact of the surfaces. As the distance between centers of shafts increases, the driver and follower for such methods...
-Crowning Pulleys
Suppose that a flat belt is placed on the side of a double cone, Fig. 95, and that we start to rotate the cone in the direction of the arrow. The edge E, which is stretched more tightly than F, has a ...
-Belts with Shafts Not Parallel
Suppose an open belt to connect pulleys A and B1, on parallel shafts, Fig. 97. Draw a tangent XY to the pitch circles of the pulleys at the points L1 and L2 ,where the belt leaves the pulleys. Now ...
-Quarter-Twist Belt
By rotating the central plane of B, Fig. 97, until the angle C becomes 90, a quarter-twist, or half-crossed belt: Fig. 98, is obtained; and if angle C becomes 180, the crossed belt of Fig...
-Reversible Quarter-Twist. Two Guide-Pulleys
In order to reverse a quarter-twist belt, it will be necessary to introduce one or two guide-pulleys to bring the center line of the belt at all times into the central plane of the receiving pulley. F...
-One Guide-Pulley
Fig. 102 shows the arrangement of the pulleys for the belt to run in either direction, using only one guide-pulley. The ordinary direction of rotation is that shown by the arrows. The upper pulley is ...
-Belts Connecting Shafts In Same Plane But Not Parallel
It very often happens that a belt must connect two shafts which are on the same level, but which are not parallel. The connection can be made, whatever the angle between the shafts, by the use of two ...
-Cone Pulleys
It is often necessary to provide a range of speed variation in a shaft belted from a line shaft running at a constant rate. A familiar case of this kind is the ordinary lathe spindle. This may be done...
-Belt Holes
Very often a belt has to pass through a floor or partition. The holes through which the belt runs should be large enough to be sure that the belt shall never strike the sides, but it is desirable that...
-Belt Drive General Practice. Working Conditions
A belt drive is working under the most favorable conditions when, though not pulled up excessively, the belt hugs the pulleys tightly and wraps a large proportion of their circumference. Slipping...
-Machine Drawing. Gears
General Theory Of Gears Fig. 111 represents a pair of disks fastened to shafts A and B, respectively, and touching at the point P. If these disks be pressed tightly against each other, sufficient f...
-Cycloidal Gears
Two kinds of curves fulfill the requirement for gear teeth, that the common normal shall pass through the pitch point. These are the cycloidal and involute curves. The latter curve, for many reasons, ...
-Method Of Drawing Gears
The steps in the process of drawing the gears are as follows: 1. Calculate the diameters of the pitch circles. 2. Draw the center line X Y on the paper; and on this center line locate the center...
-Annular Gears
An annular gear is a ring with teeth on the inside of it. Fig. 115 shows such a gear, with center at A, meshing with its pinion. The method of drawing such a pair of gears is similar to that just desc...
-Rack And Pinion
A rack is a gear whose pitch line is a straight line instead of a circle. Fig. 116 shows an epicycloidal rack in gear with a 16-tooth pinion. The describing circles are of the same size in the figure,...
-Involute Gears
Involute Compared With Cycloidal Gears We have seen in the preceding pages how the outlines of cycloidal gear teeth are generated by a point in a circle rolling on the pitch line. We have noted tha...
-Bevel Gear
Bevel gears are used to connect shafts whose axes intersect. The angle between the shafts is not necessarily a right angle, but this is the most common angle used. Fig. 119 shows a pair of bevel gears...
-Machine Drawing. Part III A. Mechanical Working Shop Drawings
In Mechanical Drawing, Parts I to III, inclusive, the funda-mental principles were explained and illustrated. In Machine Drawing, Parts I and II, the production of working drawings has also been discu...
-Plan And Scope Of Advanced Work. Utility The Guide
It is now intended to throw an entirely different light on the matter, and view the subject of Machine Drawing from a purely practical standpoint, that of utility. It is assumed that the student under...
-Plan And Scope Of Advanced Work. Utility The Guide. Continued
Cost Of Producing Drawings The second general element involved in producing shop drawings is their cost, as measured by the draftsman's time. It is somewhat subordinate to the first element, for th...
-Duplex Pump Plates
Reasons For Choice Of Pump Specifications The typical set of plates chosen for this book in fulfillment of the above purposes, takes up the study of a simple, duplex steam pump. This particular typ...
-Plate A. Steam End Layout Mechanical Drawing
This plate illustrates, as nearly as reproduction can accomplish, the pencil layout of the steam end. It is the first work of the designing draftsman. The drawing as shown is exactly the type of layou...
-Plate A. Steam End Layout Mechanical Drawing. Continued
Port Details The size of steam ports having been calculated, they may be drawn in, the turns being made easy and as direct as possible. The height to valve seat must be kept at the lowest limit con...
-Plate B. Steam Cylinder Mechanical Drawing
After the exact and complete development of the steam-end layout, the student should be pretty thoroughly acquainted with the details of the cylinder. All the work thus far has been entirely for his o...
-Plate B. Steam Cylinder Mechanical Drawing. Part 2
Complete Development Of Different Sections It is not economy of time to finish one view before beginning another. It is better to take some single detail of the drawing and develop it in all views,...
-Plate B. Steam Cylinder Mechanical Drawing. Part 3
Accuracy Of course the dimensions on a drawing must be accurate. It is, however, a very easy matter to make errors. To insure accuracy a figure must never be put down carelessly, and a constant wat...
-Plate B. Steam Cylinder Mechanical Drawing. Part 4
Principal Titles The principle title of a drawing should contain at least seven items: (1) name of principal details shown; (2) name of machine; (3) firm name and location; (4) scale of drawing; (5...
-Inking Dimensions And Letters
Extension lines may be dotted, as explained in Mechanical Drawing, Part HI, or they may be fine, full lines, the latter method being illustrated in the series of pump plates in this paper. Dimension l...
-Most Common Abbreviations In Use On Working Drawings
A list of the most common abbreviations in use on working drawings follows. This list has been adopted for the plates in Machine Drawing Part I: F. A. O............ finished all over. f............
-Plate C. Piston Rod And Valve Stem Mechanical Drawing
Specifications The piston is of the one-piece box type, with sprung-in rings. The width is reduced to 4 7/8 inches at the outside, so that if the piston strikes the cylinder heads it will not tend ...
-Plate D. Steam Chest And Valve Mechanical Drawing
Specifications The steam chest in this instance is located on the cylinder by fitting down over the ledge made by the valve seat. The side flanges also serve the purpose of guiding the valve. It wi...
-Plates E And F. Valve Motion Layout Mechanical Drawing
General Specifications These plates represent the layout of the valve motion, and are necessary in order to find the length of the levers and rocker arms. It will be noticed in Plate F that the val...
-Plate G. Valve Motion Details Mechanical Drawing
Piston-Rod Levers The piston-rod levers on this plate are specified to be steel forgings. Forgings of this kind are expensive, but are light, neat, and reliable for the important service which they...
-Plate H. Yoke, Stuffing Boxes, Bracket, Etc Mechanical Drawing
Having worked up the layouts of Plates E and F, the student has enough information to proceed with Plate H. This, like Plate B, is without dimensions, the student's work being to make the drawing and ...
-Plate I. Water End Layout Mechanical Drawing
Specifications In the preceding work, the completed plates were used to assist the student in developing the layout drawings for other parts of the pump. In this Section, Plates K and L bein...
-Plate J. Water Cylinder Mechanical Drawing
Complications In Design The water cylinder is, perhaps, the most complicated detail that the student will meet in this set of plates. Fundamentally, it is simply a box with curved sides, divided by...
-Plate K. Water Cylinder Cap And Air Chamber Mechanical Drawing
Specifications For a water cylinder cap of this size, the most difficult problem is to find room for the hand-hole bosses. A hand hole 4 inches X 6 inches is about as small as can be used, and this...
-Plate L. Plunger And Valve Details Mechanical Drawing
Specifications Plate L is noticeable for illustrating a method of drawing details not used elsewhere in this set of plates. On the other plates each piece is separately detailed. On Plate L the det...
-Plate M. Foundation Mechanical Drawing
Specifications Pumps are often set directly upon a foundation of brick, but it makes a better job to bed stones, with surfaces dressed plane and true, into the main foundation, and rest the pump fe...
-Plate N. General Drawing
Assembled Parts Plate N is an example of a plain, everyday shop drawing, to show the relation of parts and the extreme space occupied by the pump. A great deal of time can be needlessly wasted in p...
-Machine Drawing. Part III B - Electrical. Introduction
Requirements Having learned the general principles involved in making a correct mechanical drawing of any part of a machine, or the machine as a whole, it might be assumed that the student was in a...
-Design Of A Direct-Current Generator
General Specifications The set of plates* which will be used presents complete drawings for a multipole direct-current generator having six main poles and commutating poles, running at a speed of 6...
-Plate A. General Outline Drawing
Plate A shows such a preliminary outline drawing. It will be seen that this drawing is more or less rough. There is no detail and there are no dimensions except such as are determined by the designer'...
-Details Of Armature And Commutator
In the case in hand, it might seem the logical thing to start with the center of the machine - the shaft - and work outward, completing each part as it is reached. However, if we start with the shaft,...
-Plate B. Armature Punchings
The armature laminations, Fig. 1, can very easily be drawn, since the designer has given all the necessary data as to dimensions, and it is only necessary for the draftsman to put this data on a drawi...
-Plate C. Armature Windings. Layout Of Winding
It will next be necessary to lay out the armature windings themselves in order that we may complete the details of the flanges and spider. Note now how the draftsman has made a diagram, Fig. 7, showin...
-Plate D. Armature Flanges And Spider
We come logically then to the armature flanges and the spider. Difference Between Front And Back Flanges The two flanges are quite similar in everything except as regards their mounting on the s...
-Plate E. Equalizer Rings And Support. General Details
The equalizer rings just referred to may now be designed. First a diagram is drawn showing the general shape and the points at which they are connected into the risers, Fig. 5. The details are next wo...
-Plate F. Commutator Details. Commutator Drawing Requires Special Care
Now we come to the commutator, clamping rings, and spider or shell. Plate F is a splendid example of detail work where the draftsman must work out dimensions to the finest point, considering only not ...
-Plate G. Armature Shaft. Details And Dimensions
The revolving parts have now been completed with the exception of the shaft. From the previous drawings all data is available for making the shaft drawing as shown in Plate G. The center lines of bear...
-Details Of Field Frame And Coils. Plate H. Magnet Frame And Base. General Details
Having completed the revolving member, we now turn our attention to the magnet frame, fields, etc. The details of the magnet frame are covered by Plate H. Certain dimensions here are fixed by the e...
-Plate I. Pole Pieces. General Details
The general outlines and dimensions of the pole pieces for the fields are determined by the electrical design, but they must all be covered completely by drawings so that they can be built in the shop...
-Plate J. Main Field Coils And Spools. General Details
Having completed the pole pieces, the fields themselves and the spools for supporting them can now be completed. Plate J covers coils and spools for the main fields. These main fields consist of two p...
-Plate K. Commutating Field Coils And Spools
The commutating fields are connected in series with the armature and carry the full machine current. They are therefore made of heavy copper somewhat like the series section of the main field. Plate K...
-Details Of Brush Rigging. Plate L. Brush Holder, Stud And Connections
The previous plates have covered all the principal parts of the machine except the parts for collecting the current from the commutator. Plate L now takes up the details of the brushes and the brush h...
-Current-Carrying Parts. Stud And Insulation Washers
The dimensions of the studs, Fig. 18, can be determined from the other drawings and from the knowledge that the yoke must be supported from a groove cut into the bearing casting. This stud must be ins...
-Plate M. Brush Holder Yoke And Brush Shifting Device. Brush Holder Yoke
The brush holder yoke, which is in two pieces, Figs. 11 and 12, so that it can be slipped into the slot on the bearing when the machine is being assembled, is made in the form of a thin wheel with pro...
-Bearings And Pedestals. Split Bearings For Armature Shaft
The machine proper, as far as electrical features are concerned, is now complete, although considerable work is still necessary 01 the connections between the fields and to the terminal blocks at the ...
-Plate O. Pedestals And Caps For Bearings. Pedestal Details
It will be noted, first, that the pedestals or standards, Figs. 2 and 13, are built with machined bearing surfaces at the bottom where they are bolted to the bed plate, or base, which has already been...
-Details Of Electrical Connections. Plate P. Assembly Of Connections
The next work which will be necessary in the drawing room is a layout of the connections between fields and between the bus rings and terminal blocks at the side of the machine. Before the actual layo...
-Final Assembly Drawing. Plate R. Outline. General Details
The final plate of this series is Plate R. This is a drawing which is entirely unnecessary from the standpoint of manufacturing the various parts of the machine, but is indispensable to the man who as...
-Gasoline Automobile Construction. Features Of Motor-Car Construction. General Outline
Groups And Parts Practically all modern gasoline motor cars may be divided, in a mechanical sense, into six groups of parts or units. These are: (1) The engine or power producing group; (2) the clu...
-Final Drive Group. Driving Shaft
The connection from the transmission to the rear axle in pleasure cars is usually by shaft, called the driving shaft. On the majority of motor trucks, however, it is by means of double side chains, wh...
-Engine Elements
The principles of engine design and the methods and details of engine construction are certainly, in interest and importance, second to none of the other factors that combine to produce the complete m...
-Engine Elements. Part 2
Cylinders Gasoline-engine cylinders are variously made of cast iron, cast and forged steel, aluminum alloys, and other materials. For durability, and the ability to withstand high temperatures w...
-Engine Elements. Part 3
Connecting Rods Established practice in connecting-rod design is almost all in favor of the common H-section rod, usually with two bolts to attach the cap. In some cases four bolts are used, since ...
-Engine Elements. Part 4
Sleeve Valves This type of valve, while not at all new, has only within the past few years come into considerable prominence, chiefly as a result of the truly remarkable performances of the Knight ...
-Gasoline Automobile Construction. Cams
Friction Granting the necessity for proper means to regulate the inflow and outgo of the charge and consequent products of combustion, as exemplified by the valves, the next most important part is ...
-Gasoline Automobile Construction. Cams. Continued
What Good Modern Practice Shows A more modern way, which is fast becoming universal, is to use straight sides for the cams and take advantage of rapid closing in another way, the benefits of which ...
-Repairing Valves And Valve Parts
The interest of the repair man in all these valve-motion parts is quite different from that of the designer, for he cares not so much how they are made as how they are taken out, repaired, and put bac...
-Sliding Sleeve Valves
A method of avoiding cams, and with it all cam troubles, is the use of a sliding sleeve in place of a valve, slots in the sleeve corresponding to the usual valve openings, both as to area and timing. ...
-Rotating Valves
Successful Operation Requires Two Valves In addition to rotating and reciprocating sleeves and reciprocating valves, the rotating valve has been tried, in common with any number of other devices in...
-Miscellaneous Motor Repair Work
Cylinder Heads A great many motors have detachable heads and their quick removal is a great convenience, when there is carbon to be scraped off, pistons to be looked over, or other internal work to...
-Curing Excessive Lubrication. Holes In Cylinders
When it comes to drilling holes, to provide an outlet for the excess oil in the cylinders and so to reduce smoking, small holes. -inch for example, are sufficient and may be drilled in on any spiral ...
-Piston Troubles. Frozen Or Clogged Pistons
Sometimes, the pistons will apparently be frozen in the cylinders, particularly in very cold weather and when fairly thick oil is used. This is but a temporary trouble and can be cured by pouring in a...
-Clutch
Classification Principal among the indispensable parts intervening between engine and road wheels, and one which may be a source of great joy or correspondingly great wrath, according to whether it...
-Cone Clutch. Single Cone Type
This consists of two members, one fixed on the flywheel or other rotating part of the engine, the other fixed to the transmission shaft. The latter usually slides upon the shaft so as to allow engagem...
-Requirements Applying To All Clutches
In a serviceable clutch there are two general requirements which are applicable to all forms. These are gradual engagement and large contact surfaces, although the latter requirement may be made to lo...
-Contracting-Band Clutch
A short consideration of the band style of clutch shows that this does not differ radically from the ordinary band brake, either in construction, application, or actual working. The difference in the ...
-Expanding-Band, Or Ring, Clutch
The expanding-band clutch finds favor among few. Like the contracting band, which is very similar to the band form of brake, the expanding band is much like the expanding type of brake, with the excep...
-Multiple-Disk Clutches
The modern tendency in disk clutches, however, is away from those of few plates requiring a very high spring pressure - since the friction area is necessarily limited - toward the multiple-disk variet...
-Metal-To-Metal, Dry-Disk Type
This method has the additional advantage that the central part within which the clutch is housed is very small in diameter, so that the portion of the flywheel between the rim and the clutch housing m...
-Hydraulic Clutches
All the methods of engaging and disengaging the engine at will, as discussed before, have been of a mechanical nature. The hydraulic clutch, on the other hand, partakes more of the fluid nature, altho...
-Magnetic Clutch
All the foregoing clutches present in one form or another very complicated devices for freeing the transmission shaft from the engine shaft, but the magnetic clutch is a device which has simplicity fo...
-New Electric Generating Clutch
So great has been the interest in the various electrical mechanisms in the automobile, and so quickly has the public taken up with all these that this has stimulated an entirely new invention, called,...
-Clutch Operation
Practically all modern clutches are operated by means of a special pedal, moved by the left foot. This is connected by means of rods and levers to the internal member, which compresses the clutch spri...
-Clutch Troubles And Remedies
The very fact that the clutch is a more or less flexible - or rather, variable - connection between engine and road wheels makes it necessary that it be kept in the best of shape. It is rather surpris...
-Transmission
Primarily, the clutch is used to allow the use of change-speed gearing; or, stated in the reverse way, the form of the transmission determines whether a clutch must be used or not, there being cases i...
-Sliding Gear
General Method Of Operation Of the different types of sliding gears, the first two subdivisions are not very closely marked, but blend somewhat into one another. The only real difference between th...
-Four-Speed Type Gear With Direct Drive On High
One of the tendencies of recent years has been the gradual change toward more speeds, as shown by the increasing use of four-speed gear boxes. Other indications of this have been the two-speed axle, w...
-Electrically Operated Gears
In substance, the electrically operated transmission has all the hand levers, rods, and other levers replaced by a series of push buttons. When it is desired to change speeds even before the actual ch...
-Transmission Troubles And Repairs
Noise In Gear Operation One of the most common of transmission troubles is noise in the operation of the gears, generally a grinding sound. This is heard more in bevels than in spurs, but in old tr...
-Gasoline Automobile Construction. Gears
Since the whole subject of transmission concerns itself with gears, it will not be out of place to discuss the gears themselves and describe the many different kinds in use. Speaking broadly, the gear...
-Frame Troubles And Repairs
The more usual troubles which the repair man will encounter are sagging in the middle; fracture in the middle at some heavily loaded point or at some unusually large hole or series of holes; twisting ...
-Spring Troubles And Remedies. Usual Spring Troubles. Lubrication
The average repair man is apt to have more call to lubricate the leaves of a spring than any other one thing in connection with springs. True, they lose their temper, sag, and show signs of losing the...
-Front Axle Troubles And Repairs
Alignment Of Front Wheels Troublesome The lack of alignment of front wheels gives as much trouble as anything else in the front unit. This lack not only makes steering difficult, inaccurate, and un...
-Rear-Axle Troubles And Repairs
Jacking Up Troubles Much rear-axle work - practically all, in fact - calls for the use of the jack. True, the full-floating type of axle can have its shaft removed without jacking, but aside from d...









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