r M EACDICAI/ % FOR. VEH DRAFTSMEN^MECHANICS Class _ Book. Gopyri!^htN"_ COPyKIGlIT DEPOStr r R. B. BIRGE and HUGH M. SARGENT, Authors PRACTICAL PROBLE/^ FOR VEHICLE DRAFTSMEN AND MECHANIC; WARE BROS. COMPANY, Publishers 1 010 Arch Street, Philadelphia, Pa. o-^^ Copyright by BiRGE & Sargent 1912 f A 0" CCI.A3i,91G4 CONTENTS PAGE Introduction 4 Geometrical Terms and Definitions 5 To Divide a Line in Any Xnmber of Eiinal Parts 10 To Lay Out True Sweeps or Curves 11 To Find the Radius of an Arc 13 To Lay Out Ovals 14 The Application of the Proportional Triangle for Laying Out Twisted or AVinding Sxirfaces 16 Construction of Joints IS Laying Out a Proportional Corner, Losing Proportional Triangles. . 22 Laying Out a Proportional Corner, L'sing Parallel Lines and Intersections 24 Laying Out Seat Panels, the Dihedral Angle and iliters of a Wagon Seat 20 The Framinii' of Bodies With Contracted and Flared Sides 28 The Proportional Corner, Horizontal Sect Laying Out Twisted or Winding Surfaces Laying Out a Belt Line and Moulding. . . Pricking Off Corner Pillar on Twisted Si Laying Out a Coupe Pillar Framing Up a Door The Construction of Glass Frames Laying Out a Wheel House and Rear Mi Laying Oiit a Pattern of Panel for a Meti Laying Out a Pattern for a Shroud Pane' Laying Out Patterns for a Front Mud G\ Perspective Drawing of Vehicles Colorino- Carriage and Automobile Drawii Working Drafts INTRODUCTION k is the outgrowth of practical experience in ss room. The authors, while intimately con- with the vehicle industry, in 1909 conducted ning school in carriage drafting, the pupils o{ about twenty-five in number, were all employes nent. The results of the first year were so ouch benefit was experienced by the students ntinued through another year with an equally instruction proceeded, many problems came up ition in relation to the highly technical work of ly maker. These problems were exactly such 1 any day in actual practice in any vehicle ich the student finds himself employed. Noteg iC practical problems, and their solutions, and e basis or foundation for the present volume, ions that had been answered and elucidated m thors have incorporated in this book a number problems, and the whole is now offered to all amcs in the vehicle trade who are seeking to 1 education in order to advance themselves in altogether with the object of aiding aspiring )ok was compiled and placed on the market of elementary plane geometry is indispensably inderstand the principles upon which the art of rests. For the benefit of those who have not this preliminary training the subject has been introduced in the first section of the book. A careful perusal of this section will give the student an insight into the principles of plane geometry, and enable him to more clearly understand the technical terms necessarily employed later on. These principles are in fact very simple and easy to understand, but because they are so important and so constantly referred to in practical drafting, it is necessary for the student to have a clear working knowledge of them. It is the purpose of this book to leach not only the practical applications of each problem, but also to convey a familiarity with the principles underlying each problem. Therefore, in preparing each illustration, those parts have been selected which are as simple as the case may permit, although they are not always in the best proportion. In a number of instances it was necessary to exaggerate the relations of the lines in order to explain the problem to the best advantage. Great care has been taken to have the drawings and text accurate as the authors could make them, but as most of the work was done by busy men in their evening hours, it is possible that a few errors may have escaped their notice. Should any one discover discrepancies or mistakes of any description in the book the authors and publishers will consider it a favor if the information is brought to their attention. There has been an insistent demand for a book of this character from the actual workers in the vehicle trades, and if this book meets that demand, or serves in any manner toward elevating the standard of technical education among the vehicle mechanics for whose benefit it was compiled, the authors will feel more than gratified with such a reward for their labor. R. B. BIRGE. HUGH M. SARGENT. PkACTIC^U. PfiOBLEilS FOR VEHICLE DRAFTSMEN AND MECHANICS. Geometrical Terms and Definitions A LINE is that which lias length merely, and may be sti-aight or curved. A STRAIGHT LINE, or, as it is sometimes called, a right line, is the shortest line that can be drawn between two given points. Straight lines are generally designated by letters or figures at their extremities, as A B, Fig. 1. A CURVED LINE is one w-hich changes its direction at every point, or one of which no jjortion, however small, is straight. It is therefore longer than a straight line connecting the same points. Curved lines are designated by letters or figures at their extremities and at intermediate points, as A B C or D E F, Fig. 2. PARALLEL LINES are those which have no inclina- tion to each other, being everywhere equidistant. A B and A' B' in Fig. 3 are parallel straight lines, and can never meet, though produced to infinity. C D and C D' are parallel cm-ved lines, being arcs of circles which have a common center. HORIZONTAL LINES are hues parallel to the hori- zon, or level. A Horizontal I^ine in a drawing is indicated by a line drawn from left to right across the j^aper, as A B in Fig. i. VERTICAL LINES are lines parallel to a plumb line susjiended freely in a still atmosphere. A Vertical Line in a drawing is represented by a line drawn up and dowai the j^aper, or at right angles to a horizontal hue, as E C in Fig. 4. INCLINED OR OBLIQUE LINES occupy an inter- mediate between horizontal and vertical lines, as C D, Fig. 4. Two lines which converge toward produced, would meet or intersect, { other. PERPENDICULAR LINE ular to each other when the angles c of meeting are equal. Vertical and 1 perpendicular to each other, but pe always vertical and horizontal, but i to the horizon, provided that the an point of intersection are equal. In I are said to be perpendicular to A B. E F are jjerpendicular to A B. I^ same line are parallel to each other, which are perpendicvdar to A B. An ANGLE is the opening b which meet one another. An angle by three letters, the letter designatii straight lines containing the angle other two letters, as the angle E C I A RIGHT ANGLE.— Whe another straight line so as to make th each other, each angle is a right angk said to be perpendicular to each othei Fig. 7.) An ACUTE ANGLE is an an as A B D or A B C, Fig. 7. An OBTUSE ANGLE is an ; angle, as A B E, Fig. 7. Practical Pkoblems fob Vehicle Dkaftsmen and INIechanics. GEOMETRICAL TERMS AND DEFINITIONS— Continued GHT-SIDED FIGURES. ', is tliat which has length and breadth L surface such that if any two of its points ight hue, such line will be wholly in the [•face which is not a plane surface, or lurfaces, is a curved surface. CURVED SURFACE is one in wliicli lay be joined by straight lines which shall "ace. The rounded surface of a cylinder curved surface. CURVED SURFACE is one in which te joined by a straight line lying wholly i surface of spheres, for example, is a ;e. iNUSE is the longest side in a right- the side opposite the right angle. A C, a triangle is its upper extremity, as B, ■ailed vertex. a triangle is the line at the bottom. B C 10. a triangle are the including lines. A C, 8 and 9. is the point in any figure opposite to and ise. The vertex of an angle is the point the angle meet. B, Fig. 9. The ALTITUDE of a triangle is the length of a perpendicular let fall from its vertex to its base, as B D, Fig. 9. A QL^ADRILATERAL figure is a surface bounded by foiu' straight lines. There are three kinds of Quadrilat- erals: The Trapezium, the Trapezoid, and the Parallelogram. CIRCLES AND THEIR PROPERTIES A CIRCLE is a plane figure bounded by a curved line, everywhere equidistant from its center. (Fig. 10.) (See also Circumference. ) The CIRCLT3IFEREXCE of a circle is the boundary line of the figure. (Fig. 10.) The CENTER of a circle is a point within the circum- ference equally distant from every point in its circumference, as A, Fig. 10. The RADILTS of a circle is a line drawn from the center to any jjoint in the circumference, as A B, Fig. 10, that is, half the diameter. The plural of radius is radii. The DIAINIETER of a circle is any straight line drawn through the center to opposite points of the circumference, as C D, Fig. 10. A SEMICIRCLE is the half of a circle, and is bounded by half the circumference and a diameter. (Fig. 11.) A SEGMENT of a circle is any part of its surface cut off by a straight line, as A E B and C F D, Fig. 12. Practical Problems for Vehicle Draftsmen and Mechanics. Fig. J A B Fig. 2 Fig. 6 Fig. 10 Fig. 3 A_ A'_ B B Fig. 4 p^ •^ypo-u.^ B Fig. 5 "H~ Fig. 7 Fig. 8 Fig 9 T Fig. 11 Fig. 12 Fig. 1 3 ILLUSTRATIONS OF GEOMETRICAL TERMS AND DEFINITIONS. Practical, Problems for Vehicle Draftsmen and ^Mechanics. I I '.2 B C F Fig. 6 Fio /o Fio 14 3 B B J P IT Fig. 7 '3 D. 4 Fig. 8 CLh^ Fig. 9 B Fig // Fig 12 Fg./3 Fig. 15 Fig. 16 Fig 17 ILLUSTRATIONS OF GEOMETRICAL TERMS AND DEFINITIONS. Practicai. Problems for Vehicle Draftsmen and INIechanics. GEOMETRICAL TERMS AND DEFINITIONS— Continued An ARC of a circle is any part of the circumference, as A B E and C F D, Fig. 13. A CHORD is a straiglit line joining the extremities of an are, as A E and C D, Fig. 13. A TANGENT to a circle or other curve is a straight line which touches it at only one point, as E D and A C, Fig. 14. Every tangent to a circle is perpendicular to the radius drawn to the point of tangency. Thus E D is per- pendicular to F D, and AC to F B. CONCENTRIC circles are those which are described about the same center. (Fig. 15.) ECCENTRIC circles are those which are described about different centers. (Fig. 16.) A DEGREE. — The circumference of a circle is con- sidered as divided into 360 equal parts, called degrees (marked °). Eacli degree is divided into 60 minutes (marked ') ; and each minute into 60 seconds (marked "). Thus if the circle be large or small the number of divisions is always the same, a degree being equal to 1 360 part of the whole circimiference; the semicircle is equal to 180°, and the quadrant to 90". The radii drawn from the center of a circle to the extremities of a quadrant are always at right angles with each other; a right angle is therefore called an angle of 90" (A E B, Fig. 18). If a right angle be bisected by a straight line, it divides the arc of the quadrant also into two equal parts, each being e(|ual to one-eighth of the whole circumference, or 45° (AEF and FEB, Fig. 18); if the right angles w^ere divided into three equal parts by straight lines, it would divide the arc containing 30" (AEG, GEI the degrees of the circle are used by an angle of anj' number of dt a circle with any length of rad of the compasses in its vertex, intercept a portion of the circle e( given. Thus the angle A E H, CONCAVE means hollowe the interior of an arched surface to convex. (Fig. 17.) A CONVEX surface is one is regularly protuberant or bulginj The opposite of convex is conca Peacticai- Problems foe Vehicle Draftsmen and Mechanics. ; Off Equally a Number of Parts on a Line, the Length of Which is Given N \ \ \ ^. \ ^ '-> yv- \ \ \ \ ^^ \ r 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 a 3 4 5 6 1 d d iO u V. L s to divide a line 614 inches long into s. The easiest and quickest method is Fig. 1. Draw a perijendicular Hne scale L from a until 8 inches strike the perpendicular line drawn from line O at h. JNIark each incli from the scale on to the drawing, and project on to line O, establishing points I, II, III, IV, V. VI and A^II, wliich are equally spaced on line O. Practical Problems i'or Vehicle Draftsmen and Mechanics. The Laying Out of True Sweeps or Curves when th Amount of Sweep or Curve is Giver F''OR laying out true sweeps or curves where it is impractical to strike the radius with the compasses or trammel points, we illustrate the following example, and although the principle has long been in use, it is unknown to a great many mechanics. For the examijle let us say of 4 inches in a length of 40 ini line two points 40 inches apart, nail as illustrated in Fig. 1. Hal lay out on a perpendicular line a Practical Pboblems foe Vehicle Dkaftsmen and Mechanics. ^ OF TRUE SWEEPS OR CURVES WHEN THE LENGTH AND AMOUNT OF SWEEP OR CURVE IS GIVEN— Continued nt anotlier nail. Next take two sticks. in the length of the sweep, and secure on the nails and forming a triangle, in Fig. 1 represent the sticks, and N I'e placed tight up against the nails and that they cannot change their angle, nd notch out the sticks at this point so nay be placed therein, 'eep, work the sticks back and forth in Fig. 1, being sure to have the sticks In this way a sweep of any length lis system will be found very convenient in cases where the radius is too great to be reached by the comjiasses or trammel points. It is usually customary to form the sticks as shown in Fig. 1, and place the pencil on the inside of the sticks as shown, but in some cases it is desirable to construct the sweep as shown in F^ig. 2, with the outside of the sticks bearing against the edge of the nails, and the pencil being placed in the notch on the outside of the sticks. Although this is sometimes desirable, we believe it will be found more con- venient to lay a s\veep out as illustrated in Fig. 1, inasmuch as one need not be particular in fastening the sticks together, except that they nuist be fastened securely so that they will not change their position in relation to the nails. Practical Puoblems for Vehicle Draftsmen and Mechanics. To Find the Radius of an Arc AN ARC FOR WHICH WE WISH TO FIND THE CENTER OR THE RADIUS. ANOTHER METHOD OP FINI REFER to a-c in Fig. 2. an are for wliich we wish to find the center or the radius that descrihed same. Take point h, which is midway hetween a and c. and describe arc 1 tlierefroni. tlie radius of which is greater than lialf the distance from a to b, or from b to c. With the same radius centered at a and c, describe arcs 2 and 3, passing througli arc 1 described from b. Draw tlie hues -i and IV through inter- section of arcs, and Avhere these Hues intersect at O we will have established the center from Avhich the large arc a-c was described. Fig. 3 illustrates another ni of an arc by the use of a squf arc x-n which is at 1. Draw s X, 1 and n. Find the center of li the square placed on line 1-n. from c. Then with the square pli line perpendicularly from the cei intersects that drawn from c a the arc x-n. Pbactical Problems for Vehicle Draftsmen and Mechanics. Laying Out Ovals ONE SYSTEM FOR FINDING AN OVAL. al systems for laying out a true oval, cle we will explain and illustrate three ular. is illustrated in Figure 1. A square ihape of a cross, and is grooved out as 2 two adjustable pins or studs secured y-x. Decide upon the length and width 18 inches long and 9 inches wide. I^ay oint on the stick one-half the width of inches, from z to x. Locate one of the With one-half the length of the oval. which Avould be 9 inches, lay same off on the stick from z to y. Set the adjusted pins into the grooves in the cross frame and work the same up and down, and back and forward on the frame, having the pencil point bearing on the paper and describing a true oval aroiuid the cross frame. FigiH'e 2 illustrates anotlier method for laying out an oval, and when there are no instruments at hand, same will be found very convenient. Lay out the horizontal and vertical center lines of the oval, and on same lay out the length and width desired. Take one-half the length of the oval from x to a and lav this distance out from c until same strikes the horizontal Practical, Problems for Vehicle Draftsmen and Mechanics. LAYING OUT OVALS— Continued center line of the oval at e and h, at which points locate two pins or tacks, as illustrated. At point c locate another pin or tack, and around these three pins or tacks tie a piece of string taut, forming a triangle e-h-c. Remove the pin or tack at c, and put the point of a pencil in its place. Keeping the ANOTHER SYSTEM FOR FINDING AN OVAL. string taut, with the pencil back of same, work the pencil P around the pins, which operation will produce a true oval. Fig. 3 shows another handy system for laying out a true oval. Draw the horizontal and vertical center lines of the oval, and determine the length and width. From O, the center of the oval, draw a circle B, the diameter equal to the width of the oval. Draw another circle diameter of which will be equal Space off a number of points 1, A, and connect with the center o lines drawn from 1, 2 and 3 inters LAYING OUT A TRUE horizontal lines, outward, and fro outer circle A, drop vertical proj horizontal lines drawn from the i The same operations apply for ob required, and after same are foui them with graceful sweeps which Practical Problems for Vehicle DrxVftsmen and Mechanics. application of the Proportional Triangle for Laying Out Twisted or Winding Surfaces 1 triangle will be used to a great extent e following problems for laying out pro- -luiders of twisted or winding surfaces, tliese advance problems will be found ing the student for some of the more taken uj) in some of the following ain Fig. 1. The turn-under sweep B-Z id from this line, providing we know the turn-under, we may work proportional r any part of the body. B-Z being the 5WTe]i, we desire to find out the correct ler sweep for another part of the body ill amount of turn-under is ecpial to the I on line O-O, Fig. 1. ine Z-X be drawn through the horizontal a triangle BCX below line O-O. Point med turn-under sweep. Point C is fixed I-X as drawn from the top of the body base line 0-0, and, in completing the :nt we have to determine is X, and this arily on the vertical line Z-X and to suit have point A also fixed by the over-all r sweep which we wish to proportion, so ; another triangle ACX, X being the th triangles. Xow we have laid out a triangle for each turn-under, and it is by means of these triangles and the assumed turn- under sweep that we will develop the greater turn-iuider sweep A-Z. Passing through the assumed turn-under sweep B-Z and the vertical line Z-X, lay out a number of lines I, II and III at will above the horizontal line O-O. Where each one of these lines passes through the assumed turn-under sweep B-Z. take I for instance, drop a vertical line until we strike the hypothenuse for the proportional triangle of the assumed turn-under sweep. From this point draw a horizontal line passing through the triangles and number it 1. Whei'c this line strikes the hyjjothenuse of the larger projjortional triangle, erect a perpendicular line until line I is reached, thus estab- lishing a point through which the correct projiortional turn- under line A-Z must pass. Continue this operation with the remainder of the points, and connect with a graceful sweep, and we will have obtained a correct proportional turn-under, line A-Z, to the assumed turn-under, B-Z. In Fig. 2 we illustrate another example which is equally important as that of Fig. 1. AVlien a l)ody is constructed with untwisted sides as far as the seat bottom, and in this illustra- tion. Fig. 2, we will consider that the seat frame or the commencement of the twist is from line IV. B-Z is the assumed turn-under sweep. A-Y is the amount of turn-under at another part of the body for which we wish to proportion the turn-under sweep, having the same twist from the under Practical Problems for Vehicle Draftsmen and Mechanics. THE APPLICATION OF THE PROPORTIONAL TRIANGLE FOR LAYING OUT WINDING SURFACES— Continued side of the seat or line IV. Draw the straight hue Z-X as a continuation of the body Hne before it commences to turn under at IV. It is on Hne Z-X that we locate the common apex X of our proportional triangles, which, as in Fig. 1, is determined at will. Lay out the proportional triangles BCX and ACX for the assumed turn-under sweep and the desired turn-under sweep, respectively. Space off a niunber of lines I, II, III and IV j^assing through the assumed turn-under sweep. Wherever these lines cut the assumed turn-under sweep, line B-Z, draw lines down on to the proportional tri- angle parallel with the outside line Z-X. Where these parallel lines strike line B-X of the triangle BXC, draw horizontal lines 1, 2 and 3 passing through the line A-X of the larger proportional triangle ACX. Project these points up and £ parallel to the outside line Z-X until lines I, II and III are intersected, thus establishing points through which the desired turn-under sweep will pass. The only difference between this problem and that in F^'ig. 1 is that, instead of the usual vertical projections from the assumed tin-n-under sweep to the proportional triangles, O- the projections are parallel with the outside flared line Z-X. Fig. 2. Pkactical Problems for Vehicle Draftsmen and jNIechanics. Construction of Joints :liis subject as we would like would require n this hook than can he spared; therefore lin hriefly the ordinary construction of the in body-making, and we believe that the found of great value to the beginner, and re for fiu'ther study in this very important ED OR LAPPED JOINTS lit varies in shape and arrangement with he pieces united. A full lap is used when the other to its full thickness; a half lap ted is cut away, whatever the shape of the mimon expression, "half-laj^ped," does not '.e united must be cut half away. le framing up of a toe bracket, each piece ito the other. In the sill and angle piece rabbet for the floor board, as shown by In Fig. 2 is shown a batten or strainer I with a feather-edge laji joint. As this [las little work to do other than that of 1 shape and supporting it. this kind of a one more complicated. Fig. 3 illustrates Dof bow into the head rail of an enclosed ipped joint. Fig. 4 illustrates a section of the post half-lapped into the sill and top rail. As an illustration of a full-la}) joint we show the floor board let into a rabbet in the sill. MORTISE AND TENON JOINT Fig. 5 shows the two pieces to be united which form this joint. Note that they are l)oth of the same thickness, and A is cut away equal on both sides for the tenon. The projecting part c on A, Fig. 5, is the tenon, and d in B is the mortise, e is the shoulder of the tenon, which is equal on both sides, f is usually one-third of the thickness of A and B. BARE-FACED TENON AND MORTISE In Fig. 6 we illustrate a bare-faced tenon and mortise joint. This means that the face of the tenon, or both faces, are exposed. The bare-faced tenon and mortise is used when two pieces are joined endways in the same direction, or endways in different directions, as shown in Fig. 6. STUMP TENON. Fig. 7 shows a mortise, tenon and stump joint, and is frequently used in framing up parts where certain joints should not be exposed as they are in Fig. 6. The stump reinforces and prevents twisting. OPEN MORTISE, TENON AND MITER JOINT This joint is illustrated in Fig. 8, and is used in framing up parts where it is undesirable to have the joints exposed. Practical Problems for Vehicle Draftsmen and Mechanics. ILLUSTRATING THE CONSTRUCTION OF JOINTS. Practical Problems for Vehicle Draftsmen and Mechanics. CONSTRUCTION OF JOINTS— Continued E TENON AND MORTISE )n and mortise joint is illustrated in Fig. 9, ling the fence bar a into the door pillar b. ikes a stronger joint than with a single cases a single mortise and tenon joint is 't is also illustrated in Fig. 0. the lock to the pillar b. FALSE TENON a false tenon for joining a frame, as case a false tenon is used on account of not as satisfactory as a bare-faced tenon In framing up parts with a false tenon, • to have the grain of the tenon cross that parts united. MITER JOINT. a simple 4<5-degree miter joint. This is TENON AND LAP .JOINT. ites a stump tenon and laj) joint, which is 1 the half-lap, and is frequently used in Is and pillars. BASTARD TENON This joint is shown in Fig. 13 in the framing of a post into a sill and where exposed joints are undesirable. It will be seen that the half -lap joint would show^ two long joints, while a mortise and tenon joint would be impractical inasmuch as the tenon would be too close to the outer surface. Fig. 1-i illustrates dovetail johits. Figs. 15 and 16 show ordinary splice joints. Fig. 17 illustrates a method for securing metal panels to body framing, and by this method we do away with exposed screw heads and nails, the metal panel being turned around a 14" x 1" flat iron which is let into a rabbet flush with the standing pillar. This is secured by means of machine screws from the inside of the post which are covered up by the trimming. Fig. 18 illustrates a method for securing the upper panels, above the belt, of a limousine bodj'. Note that this upper panel is ofi^set from the lower j^anel, and that the belt rail is rabbeted out to receive an iron plate and aroimd which is formed the upper metal panel. The lower jjanel also comes up back of this iron, forming a tight joint, the iron being secured by means of machine screws from the inside of the belt rail, as illustrated. This upper off'set panel is generally made of wood, but this construction eliminates the troubles incident to wood panel construction, over which the metal panel has the advantage. Practical Problems for Vehicle Draftsmen akd Mechanics. ILLUSTRATING THE CONSTRUCTION OF JOINTS. Practical Pkoblems for Vehicle Draftsmen and Mechanics. t a Proportional Corner by the Use of Proportional Triangles ofile or side view of an automobile seat, lalf the bottom view, and Fig. 3 is the side •f the seat. Lay out the horizontal line EC om the extreme height of the seat. This nary 6 7B C but is necessary in laying out the he corner in Fig. 2 it is necessary to assume •ound the seat, or the bottom line. In this p line EC, Fig. 2. )ut the proportional triangle FOB. BF is bevel squared down to the bottom of the ipex O should be located on the horizontal inning of the proportioning. the proportional triangle EQA, Fig. 2. of side bevel or flare taken from Fig. 3, X of the triangle, and should be located on The line AQ of the proportional triangle, I OB of the triangle on Fig. 1. angles located, lay off arbitrarily on line 1, 2, 3, 4, 5, 6, 7 and 8 around the corner, •e point up to the outside line of triangle m square point ahead until it strikes inner f. 1, at k. From this jjoint drop a perpen- ig. 2. m line EC, Fig. 2, lay out horizontal pro- side line of proportional triangle. Fig. 2, endicular line on to inner line of triangle SIDE VIEW, ONE-HALF BOTTOM VIEW AND SIDE BEVEL AND FLARE OF AN AUTOMOBILE SEAT. Practical Problems for Vehicle Draftsmen and Mechanics. LAYING OUT A PROPORTIONAL CORNER BY THE USE OF PROPORTIONAL TRI at ni. From ni draw a horizontal line back until it intersects vertical line drawn from k, Fig. 1, thus establishing the point I which is projjortional to point 1 on line EC, Fig. 2. Continue this operation with 2, 3, 4, 5 and 6, etc., and we will have obtained points on the seat frame through which the bottom line AB in Fig. 2 nnist j^ass. In order to lay out arm rail, 6 to D on Fig. 2, proceed as follows : Connect points 1, 2, 3, 4, 5 and 6 on line EC, Fig. 2, and corresponding points on line AB with straight lines. Pro- ject these same lines and points on to Fig. 1. Wherever the arm rail line cuts these lines, take s for an example. Fig. 1, square this point down until it inter on Fig. 2 at T. Repeating this op intersections will produce the poin the arm rail line should pass. D shows the amount of side arm rail on line ed. Fig. 3. This can be ajjplied for obtaining any ii lines AB and EC, provided the f all around. Do not attempt to us if the turn-under is either conca- proportional scale as explained a this book. Practical Problems for Vehicle Draftsmen and IVIechanics. ng Out of Proportional Corners by the Use of Parallel Lines and Intersections we illustrate and explain another system irojDortional corners of seats, etc. 'J'his connection with the problem taken up laying out proportional corners, but is lod which is used a great deal, and we nt to select whichever is most convenient we have adopted this system throughout ■ it the handier of the two. sary to draw out the seat in the profile e partly imaginary line a-O drawn hori- xtreme height of the seat or body. In ', assume either the bottom seat line d-D, iry line a-A taken from the horizontal line t of the seat in Fig. 1. In this problem lut the top line around the seat a-A to this line in Fig. 3, after we have obtained 1 Fig. 2 and the flare of the back in Fig. 1, I to Fig. 3, we will obtain the proportional )m and intermediate sections. around the seat, a-A in Fig. 3, lay out lamely, 1, 2, 3, 4. and 5, same being located 'e of the corner. With the use of these :d to obtani points corresponding to these ■ the seat, Fig. 3, through which the same . From point G on the center line of the seat in Fig. 3 draw a straight line connecting with point 5 on the top line of the seat, and jjarallel to this line from point VI draw another line extending indefinitely through the seat. From point A on the i)artly imaginary line a-A in Fig. 8 draw a straight line, and connect same with point 5 on line a-A, and parallel to this line draw another line from D on the front of the seat at the bottom until same line intersects the line drawn from VI at V. From each of the remaining points, 1, 2, 3 and 4, on the top line of the seat a-A, Fig. 3. draw lines to points 6 and A on line a-A, and parallel to these draw lines from VI, and from D until lines drawn from D intersect those drawn from VI at I, II, III and IV. This establishes propor- tionally points through which the bottom line of the seat d-D should pass. Now that we have the top and bottom lines of the seat, it is essential to prick off^ the arm rail line in Fig. 3, which is accomplished as follows: Project from Fig. 3 to Fig. 1 on to their relative positions lines l-I, 2-II, 3-III, 4-IV and o-V. Wherever the arm rail line passes through these oblique lines in Fig. 1 drop vertical projections until same strikes corresponding oblique lines in Fig. 3, thus establishing points through which the arm rail line shall jjass. Take the amount of flare at the front of the seat and the height of the side in Fig. 2 and transfer from D to B Practical Problems for Vehicle Draftsmen and Mechanics. in Fig. 3. Draw graceful line passing through the points already obtained, and same will jjroduce the arm rail line in Fig. 3. Now, we are supposing that the construction of this seat calls for a belt moulding or rail around the seat at the height of c-C in Fig. 1. We wish to produce this line around the seat in Fig. 3, and to accomiilish same we will take points where line c-C in Fig. 1 passes through the oblique lines 1, 2, Fig. 2 3, i and .5 and project these points down on the corresponding oblique lines 1, 2, 3, 4 and 5 in Fig. 3. Take the amount of flare at the height of C from Fig. 2, and lay same out in its correct position from D to C on the front line of the seat in Fig. 3. Also take the amount of flare at the height of c from the back of the seat in Fig. 1, and transfer from d to c on the center line of the seat in Fig. 3. Connect these points with the points already obtained on lines 1, 2, 3, 4 and 5 in Fig. 3, and we will have produced line c-C in Fig. 3, cor- responding to line c-C in Fig. 1. which is propor- tional with top and bottom sweeps of the seat in Fig. 3. Likewise any point on the liottom view of the seat in Fig. 1 can be obtained in the same manner, the system being that of projection. Fig. 3 1I.I.USTR.\TING THE LAVING OUT OF PROPORTIONAL COR: Peacticvl Problems for Vehicle Draftsmen and ]Mechanics, Out Seat Panels, the Dihedral Angle of a Corner Block, and Miters of a Wagon Seat (1 2 represent the side elevation and one- , respectively, of a wagon seat. Line be •esents the back flare; line be in Fig. 2 lare. In order to lay out the exact size d as follows: l^asses at b in Fig. 2, describe an arc ;s the vertical line at H. Project point 'ig. 1 until it strikes the vertical line F at id C, Fig. 1, gives us the exact flare of de panel. Lay out a line DC jiarallel to ide panel dc, Fig. 1, vnitil it strikes the rom d at D. Connect points D and a, ive us the front line of the seat panel, sh lines connecting a. D, C and b. Fig. 1, ze of the stock for the side panel. of the stock for the back panel, set the y. 1 and describe an arc from c, striking iL. Square this point on to vertical line ;ct with b, Fig. 2, as shown by dot and the top line of the panel parallel to line he size and shajje of the stock for the e the size of the seat panels, it is desirable dral angle or corner block bevel. From jioint III, which is taken arbitrarily, on the line of the stock, Fig. 1, draw a line jjerpendicular to the line of the stock bC, Fig. 1, until it strikes the base line at V. From the line of the stock for the back panel, bC in Fig. 2, square a line from II down to the base line at I. Point II, Fig. 2, is a horizontal jjrojection from III, Fig. 1. The next oj^eration is to draw a line perpendicular with the base from jjoint b in Fig. 2. Take the distance from V, Fig. 2, to b. Fig. 1, and lay same oif from b to V on the vertical line in Fig. 2. Take the distance from point X, Fig. 2, to III, Fig. 1, and as a radius describe arc VI from point V on the vertical line b. Next describe an arc from point I, Fig. 1, with a radius equal to the line from I, Fig. 1, to 11, Fig. 2, this arc VII intersecting arc Vl at Z. Now the dihedral angle or corner block bevel will be taken from the angle IZV. In order to find the bevel of the mitres for the seat jjanels, simply take the corner lilock bevel and bisect same as illustrated in Fig. -i. For further explanation, the dot and dash lines in Figs. 1 and 2 indicate the shape and size of the seat panels or stock when laid flat, marked by S, Figs. 1 and 2. In Fig. 3 the corner block B is illustrated, and should be planed up with the bevel as taken from IZV. Practical Problems for Vehicle Draftsmen and Mechanics. LAVING OUT SEAT PANELS AND FINDLNG THE DIHEDRAL ANGLE. Practicai, Problems for Vehicle Draftsmen and Mechanics. iming Up of Bodies Having Contracted and Flared Sides e illustrate two pi-oblems, Figs, 1 and 2, portions of seat framing showing an ned into a seat frame and top rail. The is is to show how to obtain the bevels of igle or sail that should be given the post itand in its correct position when set up and flare. is constructed with a post standing square side view, A, Fig. 1, the post cannot be th the contracted lines of the seat frame ust be set at a certain angle, so that when flared it will stand square or plumb in the amount of contraction and flare deter- bevel that should be given to the joints to stand square in the vertical plane A. equired bevel of the joints or angle of follows : t tlie side view A, having the post square I the base line. Determine the amount of 1 lay out on the end view B, and on the he amount of contraction desired. From ^e of the post where it intersects the top . 1, draw a line perpendicular with the top strikes the bottom line of the seat at III. om II, where the back edge of the post edge of the seat frame, to III on the bottom view C, and transfer from II forward to III on the bottom line of the seat in the side view A. Draw a straight line passing through I and III which will establish the angle or sail on which the post must be framed up in order to have it stand square or plumb in the vertical plane A after it is thrown around on the contraction and flare. Fig. 2 illustrates a similar example, the only difii'erence being that the post is set up on an angle or sail in the vertical plane A. In framing the post into the top rail and seat frame the bevels for the joints must not be taken directly from the side view A, but should be determined by means of the following system: From the contraction line b-d on the bottom view C, square a line from the intersection of the back edge of the l^ost with the top of the top rail at I until it strikes the bottom of the seat frame a-e at IV. From point I on the bottom view draw a line square across the body, intersecting the bottom of the seat frame line at III. Take the distance from III to IV on line a-e in the bottom view C, and lay same out on the bottom line of the seat in the side view A from the back of the post II forward to III. Connect III and I with a straight line, thus establishing the angle or sail on which the post must be framed up in order to have it conform, after it is swung around on the contraction, to the angle or sail shown in the vertical plane A. This line also establishes the bevel on which the shoulders for the joints should be cut. Practical Problems for Vehicle Draftsmen and Mechanics. REPRESENTING PORTIONS OF SEAT FRAMING. Practical Problems for Vehicle Draftsmen and Mechanics. Proportional Corner and Laying Out of Horizontal Sections and Corner Strainers on a Torpedo Body s are illustrated on the rear of a torpedo et us explain the position of the propor- Ref erring to page 24, we will find the taining the bottom line around the corner p line is assumed. will be noted that the proportioning le front of the seat on the side, and the t the rear. The points from which the ) regulate the size of the corner sonie- This, of course, is a matter of taste. If corner at the bottom, he may work the o, but the method we introduce in this ry satisfactory, and we recommend it on As Avill be noted, it gives a smaller corner SY the side view or profile of the body is , the width from the center line to Z in -under. Fig. 3 should be laid out on the 3n is to assume the line Z-Y, Fig. 2, taken Fig. 1, and Y-Z, Fig. 4, but care should a smooth and graceful line around the Dp corner sweep forms tangents to the 5, as at f and e, Fig. 2, draw horizontal lectively, until they intersect at H, Fig. 2. Fig. 2, up until it strikes the horizontal line Z-Y, Fig. 1, and from this point draw a straight line parallel to t until it strikes base line X-T at g. Square this jjoint down to the side sweep. Fig. 2 at g, and this gives us the conmiencing of the proportional corner on the side. To find out where to commence the proportional corner at the rear, lay out points A and g. Fig. 4, which correspond to A-g, Fig. 2. Connect these jjoints on Fig. 4 with a straight line. From e on the horizontal line Y-Z, Fig, 4, which is taken from center line to e, Fig. 2, draw a line at any convenient angle, say 45 degrees, until it strikes straight line connecting A and g at j. Fig. 4, from which draw a horizontal line until it strikes center line of rear view at i. Connect i and e, and we will have completed a triangle e-i-j. Draw another triangle mkl. Fig. 4, with the sides parallel to those of the triangle e-i-j, Fig. 4. At any convenient point, 1 for example, which is located on straight line passing through A-g in Fig. 4, draw a line parallel to e-j. From point k on center line of rear view, which is a horizontal projection from 1, draw a line parallel to i-e, and these two lines intersecting at m form the second triangle, mkl. Fig. 4. Connect the apexes e and m of the triangles with a straight line, and the point where same cuts the horizontal base line T-X at h, Fig. 4, gives us the point h on Fig. 2, from which draw a horizontal line until it cuts the back top sweej) at M. Now we have on Fig. 2 points A, g and M, h, from which Practical Problems for Vehicle Draftsmen and Mechanics. ILLUSTRATING THE PROPORTIONAL CORNER, HORIZONTAL SECTIONS AND CORNER STRAI Practical PROBLEiis for Vehicle Draftsmen axd ^Mechanics. PROPORTIONAL CORNER AND LAYING OUT OF HORIZONTAL SECTIONS AND CORNER STRAINERS ON A TORPEDO BODY— Continued from the top line the points necessary to ne of the corner, as in problem on page 25. )lished, continue the bottom side sweep X-g y. 2. Also lay out the bottom rear sweep MY. essary to have sections of the corner at ween the top and bottom lines of the seat 1 make the necessary forms to enable us t shape of the seat or body at a given point al and vertical lines from g and h. respec- tersect at JJ, Fig. 2. Draw a straight line , and a horizontal line through 31 and h at O, Fig. 2. enient number of points around the corner m line Z-Y, Fig. 2, as B, C, D. E. F, G, tween H and ]M only, Fig. 2, draw straight :ly until they converge at O, as from I to O, through A and g a line intersecting line Connect points B, C, D, E, F, G, between It Q. tions of sections of the body in Figs. 1, ce desired, as, for example, sections 1, 2, Take the amount of turn-under at eacli of these sections from the side turn-under at Fig. 3 and the back turn-imder at Fig. 1, and transfer same on to the lines AQ and 3I(). respectively. Fig. 2. For example, take the turn-under at III. Fig. 8. from the square line R, to convex turn-under line P, and lay it out from point A to III on line AQ, Fig. 2, and so on. On Fig. 5 is laid out the proportional scale used in finding the sections around the corner between Ag and ]Mh, Fig. 2. I.,et X-T, Fig. 5, represent the base line or X-T on Fig. 2. F^rom line X-T, F^ig. 5. first lay out the side turn-under of the body, g to A. taking same from g to A, Fig. 2. At any convenient distance from gA, F^ig. .5. lay out the amount of rear turn-under, h to ]M, from line X-T. Draw a straight line through A-]M; likewise lay out sections 1. 2. 3, -1. 5 and 6 on side and back turn-unders. Fig. 5, as taken from Figs. 1 and 3. and connect with straight lines. Transfer the turn-unders between lines Z-Y and X-T, Fig. 2. at B. C. D. E, F. G. H, I, J, K and L, laying same out on proportional scale from line X-T until they strike line Z-Y, Fig. .5. As the greatest amount of turn-under on this corner is between A and ]M. F^ig. 2. we have to extend lines X-T and Z-Y beyond 31 on the jiroportional scale. Fig. 5. Having the proportional scale complete, it only remains to lay off the different turn-unders, 1, 2, 3. 4', 5 and 6, at B, C, D, E, F, G. H, I. J, K and L from the scale on to the corresponding points of Fig. 2. Practical Problems for Vehicle Draftsmen and Mechanics. POSITION OF PROPORTIONAL CORNER AND LAYING OUT OF HORIZONTAL SEC- STRAINERS ON A TORPEDO BODY- Continued Tliis much accomplished we will connect the points between Z-Y and XT on lines B, C, D, E, F, G, H, I, J, K and L. Fig. 2, and we will have the desired sections of the corner at the heights of 1, 2, 3, i, 5 and 6, Figs. 1 and 4. On most bodies of the type illustrated here, the con- struction calls for a strainer set up and framed into the sill at the corner, as shown in Fig. 2. This strainer should be set up square from the bottom, that is, square from a straight line passing through the intersections of the outer edges of the strainer and corner at the bottom, in order to obviate as much as possible the necessity of l)eveling the strainer. In this problem we illustrate a very simple method for laying out the full size of the strainer at the front and back sides. First let us lay out the strainer on the corner of the body. Fig. 2, wherever it may be desired. Take the width of the strainer and lay it out on line X-T at ab. Fig. 2. From a straight line passing through these points, square front and back lines of the strainer through sections 1, 2, 3, 4>, 5 and 6 until they cut line Z-Y at cd, this being the top of the strainer in Fig. 2. Having determined the front strainer on Fig. 2, proceed to lay s Figs. 6 and 7. Let us lay out a stra to the front face a-e of the strainei line should be equal in height to line At right angles to this line, dra taken at the heights of these lines c sections 1, 2, 3, 4, 5, 6 in Fig. 2 ii strainer, square points on to lines 1. Connect these jjoints and it will give line V of the strainer. For the ins the thickness of strainer from line S, Fig. 6, shows the line of the stocl would be cut. The same ojjeration is applied back side of the strainer. Fig. 7, exc be squared from the back side of st I-l, IV-4 and c-d are sections of corresponding lines on Figs. 1, 2 an Practical Problems for Vehicle Draftsmen and Mechanics. ig Out of Twisted or Winding Surfaces, Illustrated on a Torpedo Body DUCE in this problem the appHcation of a [ accurate method for laying out twisted g surfaces on the side of a torpedo body irtional horizontal and turn-under sections e obtained so that after the body is con- ossess harmonious and synmietrical lines, at in the illustration of this body there is a 1 the rear corner to the dash, Fig. 2. In ; turn-under sweeps at each of the standing , Fig. 1, it is necessarjr to obtain horizontal le body at 3. 4. and 5, Fig. 1. (First the . out complete as possible, independently of ons 3, 4 and .5. The top line 2 at the waist ) should be laid out in Fig. 2.) 3, which shows the side turn-under line of the application of the proportional triangle of the turn-under line E. Having assumed take the amount of turn-under at E, Fig. 2, line VI from Q on line R, Fig. 3. Lay out V and V, in Fig. 3, at the same heights as ion lines in Fig. 1. Lay out the triangles ) from the base line VI, Fig. 3, the apex of ig located at a convenient distance below VI ;ver the sections cut the turn-under sweep action V for example, square the intersection large triangle at y. From y draw a per- itil it strikes small triangle at z. Square point from z on to the section line V again, and this gives us point through which the turn-under sweep E passes. Continue this operation with all the sections until the desired points are obtained by which the completed sweep E is determined. Now having the turn-under sweeps at A and E, let us next proceed to lay out the horizontal sections at 3, 4 and 5 through the body in Fig. 2. In order to establish these sections we will bring into use the proportional scale. Fig. 4. Let e. Fig. 4, represent the turn-under of the body at E, Fig, 2, and a the corresponding turn-under at A in Fig. 2. Lay out on e. Fig. 4, turn-unders at sections 3, 4 and 5, as taken from III-IV-V, Fig. 3. Likewise lay out the turn-unders on a. Fig. 4. Lay out straight lines between a and e at 3, 4 and 5, Fig. 4, and take the total turn-unders at D, C and B, Fig. 2, and lay them out on proportional scale in Fig. 4, at d, c and b. From this we can readily i)riek off our turn-unders at 3, 4 and 5, from d, c and b, and transfer the same on to D, C and B, Fig. 2. These jjoints established, it remains only to connect them with proper side sweej^s and we have completed the hori- zontal sections, 3, 4 and 5, from which, with lines 2 and 6, we can lay out the exact turn-under sweeps of the standing pillars at D, C and B, Fig. 1. Fig. 5 is the proportional scale used in laying out the sec- tions around the corner. Fig. 2. Fig. 6 is the proportional scale for laying out the sections through the shroud. Figs. 7 and 8, the one-half rear and one-half front views, respectively, are usually worked out after the turn-unders are determined. Practiovl Problems for Vehicle Draftsmen and Mechanics. ILLUSTRATING THE LAYING OUT OF TWISTED OR WINDING SURFACES. Practical Problems for Vehicle Draftsmen and JNIechanics. ng Out a Belt Line and Moulding for a Limousine Body ;1 graceful belt line around the corner and limousine body is sometimes difficult to I produce a working line on the. draft which in will give satisfactory results is what we vplain and illustrate in this problem. It is belt line on the back of the body should ch or sweep (usually the same as the roof), ite this, the belt line at the center of the 3m 6 to 8 inches higher than the belt line t on the side of the body, this, of course, at on the width and design of the body, etc. ■ jiosition of the belt line on the side of the nter of the back on Fig. 1. Between these he horizontal section lines II. III. IV. V Vext lay out these intermediate sections on . 2. To produce these sections in Fig. 2 service a system which has been explained in that of the proportional scale. Fig. 3. le sweej) or cin-ve, draw the line on the semi- Prom 1 to 3, number 3 being the point from n Fig. 2 conmiences to round. This back t the horizontal section lines 2 and 3, Fig. 4. from the center line of the body to each ransfer same until they strike the sections Next project points 2 and 3 from Fig. 2 responding section lines. Connecting points 1. 2 and 3 in Fig. 1 will give us the line of the belt corre- sjjonding to the line intersecting points 1, 2 and 3, Fig. 4. There now remains to be laid out the continuation of the belt line from point 3 to a in Fig. 1. This is worked out by the eye, and care should be taken to produce a graceful and true line. After the belt line on the profile in Fig. 1 is com- jjleted, project the same on to Fig. 2. and thence to Fig. 4. The line which we have established on Fig. 1 does not look as jjleasing to the eye as would be desired, but. on the other hand, after the body is constructed and the line is viewed in per- spective, it A\ill be surprising to note what a graceful and well proportioned belt line this method ^y\\\ ])roduce. It must be remembered that the corner of the limousine body is never viewed as it appears on the working drawing, but is always seen ^ith a certain amount of perspective, and apjjears very much dilFerent than it does on the draft. On metal paneled bodies the panels are joined at the belt line, and are usually covered here by a metal moulding, which is securely fastened to the body framing. This moulding is sometimes of soft metal, and sometimes of steel. If it is of soft metal it is not very difficult to form the moulding around the belt line on the job, but if it is a steel moulding that is used, it is desirable to bend or form the moulding flatwise first, and in order to do this a line should be laid out full length on a board or some indestructible article for the blacksmith, to be used in forming this moulding. To obtain the correctly developed line from the working draft, proceed as follows: Practical Problems for Vehicle Draftsmen and Mechanics. 2^Am^J__ ^ ^ Fig. 5 -ir^ LAYING OUT A BELT LINE AND MOULDING FOR A LIMOUSINE BODY Practical Problems for Vehicle Draftsmen axd INIechanics. NG OUT A BELT LINE AND MOULDING FOR A LIMOUSINE BODY— Continued horizontal line, as shown in Fig. 5. and center Hne. Square from the horizontal , e, f, g, h. i, j, the distance between each center line is taken from corresponding It line in Fig. 2. From the horizontal line ttom of the belt moulding, prick off the loulding at points b, c, d, e. f, g, etc., and ponding lines in Fig. 5. Connecting these points in Fig. 5 will give us the true shape of the belt moulding on the under side, when laid out flatwise. Gauge the top line of the moulding from this line. In Fig. 5 it will be seen that the ends of the moulding are broken off short on account of lack of space, the moulding being marked two feet longer at each end. From this point on, the moulding is straight, and it is not necessary to lay this out as long as we take the correct length from Fig. 2. Pkactical Problems for Vehicle Draftsmex and Mechanics. Pricking Off Corner Pillar on Twisted or Winding Landaulet Body with Example for Laying Out Jo LAY OUT the protile of the both' as in Fig. 1. Also draw tlie outside hue of the body Y on the bottom view. Tlien lay out parallel to line Y the bottom line of the body N-O, Avhich for a distance is an imaginary line, but is useful in laying out the cheat line. Determine the amount of cheat wanted and lav out on the bottom view of the drawing as line Q. This is also an imaginary line, considering that the body side continues down to the base line H on the eleva- tion. The adopted cheat line Q creates a twist in the side quarter of the body from vertical section line 8. This is invariably necessary on jobs of this kind for the pvn-pose of producing graceful lines on the back view of the corner in Fig. 4. To determine the amount of cheat wanted, it is some- times necessarj' to experiment until we work out what we think is the most pleasing line for the back view of the corner in Fig. 4. After the correct amount of cheat is found, we may adopt same as a standard for all jobs of this style so long as the body side sweeps and widths are uniform; therefore the line is something which cannot be developed, but must be assumed, and depends entirely upon the taste of the designer, and to execute properly requires considerable experience and skill. To prick off the rear corner of this body, take into con- sideration the twist or Avind in the side surface, and proceed as foUoAvs: In Fig. 2 lay out the normal turn-under sweep of the body at section 8 as shoAvn by the inside turn-under line O. Take the amount of turn-under from the extreme outside of the corner in Fig. 1 to the cheat line Q at the rear, and transfer on to From each turn-under as located on line line h-II, Fig. 2. h-II, Fig. 2, lay out the proport apex for same being located on liii To produce the correct pro] extreme rear corner of the body, The normal turn-under sweep space off on same a number of lii will. These lines also should pa line in Fig. 1. At the point where turn-under sweep in Fig. 2, drop ^ proportional triangle for the iK intersected, and from these jjoii striking the projiortional triangh sweej), and where same is intersect on to corresponding lines a-A, and g-G. For examjjle, take point on through which line d-D passes in line on to the line of the propor below line h-H. Square this p( of the proportional triangle, and f i l^rojection until line d-D above h jjroduces a point through Avhich 1 sweep of the body at the rear C( proceed with all the other jjoints, sweep Q in Fig. 2. Where lines Fig. 1, cut the line of the corner points 2, 3, 4, .5, 6, 7 and 8, passii of the bod}\ To produce the line of the ( and back vicAvs, proceed as folloA Practical Problems for Vehicle Draftsmen and ^Mechanics. CORNER PILLAR ON TWISTED OR WINDING SURFACES OF A LANDAULET BODY WITH EXAMPLE FOR LAYING OUT JOINT IRONS- Continued nt of normal turn-under O in Fig. 2, and e horizontal line li-H to a on line 8, in tional scale. At any convenient distance it from the horizontal base line h-H on f turn-under with the cheat as taken from . This will establish point A in Fig. 3, inected by straight line with a on line 8. if over-all turn-under on lines 2, 3, i, 5, torn view of body, and wherever these dis- nes a-A and h-H of the proportional scale ical lines passing through the scale. Con- mount of turn-unders at lines b-B. c-C, g-G, Fig. 2, from vertical line X to the iweep O, and transfer these turn-unders on g. 3. it points B, C, D, E, F and G on line 1, im vertical line X to cheat turn-under line ect corresponding points on lines 1 and 8 ght lines. ; 2, Fig. 3, take the amount of turn-under lie b-B, and transfer from the outside of :orresi3onding line 2 in Fig. 1. Continue 3, 4, 5, 6 and 7, Fig. 3, being sure to take of turn-under each time from the lines ) those in Fig. 1. ed points on lines 2, 3, 4, 5, 6 and 7 in h the bottom line of the corner j)illar must ansfer these points on to tlie rear view s so as to determine the shape and width pillar in the back view. In order to do J center line of the bottom view, Fig. 1. les 2, 3, 4, 5, 6 and 7, and Avherever the corner pillar intersects same lines, transfer distances from the center line in the back view. Fig. 4, to corresponding lines B, C, D, E, F and G. The desired points obtained, connect with graceful and pleasing sweep or curve, and we will have worked out accurately the back view of the corner pillar, from which the stock for same may be laid out with assurance that it will work out correctly. In laying out the joint irons for the tojj, the principal object in view is to illustrate an accurate system for deter- mining the center or the break of the joints. After having designed the joint irons when in upright position, and having located the jjrojjs on the profile of the body. Fig. 1, lay out a horizontal line from the center of the lower prop as shown by dot and dash line on the illustration. Take the distance from point II the center of the lower prop iron to the center of the upper prop I as a radius, and describe an arc striking the horizontal line at III. Determine the position of the center line of the upper projj I after the top is lowered, and A\ith the compasses fixed at point I, or the center of the upper prop, describe an arc V, the radius of which is greater than half the distance from I to III. With the same radius, describe arc IV from III intersecting the arc jireviously described. Lay out the center line VI, which passes through the horizontal line on which is located points II and III. This intersection determines the center or break of the top joints. From the center of the lowered prop I, to the center of the joint or break on line II-III, describe an arc striking the joint iron when in an upright position, and lay out the center a little liit above a straight line passing through points I and II. The center of the joint or break should always be ofi^set in this way in order to tighten or lock when in an upright position. Peactical Problems for Vehicle Draftsmen and Mechanics. X PRICKING OFF CORNER PILLAR ON TWISTED OR WINDING SURFACES OF A LANDAULET BODY W FOR LAYING OUT JOINT IRONS. Pbactic^u. Problems for Vehicle Draftsmen and Mechanics. 5 Out of a Coupe Pillar and Construction of Forward Part of an Enclosed Body our object is to teach the student how Lipe pillar in detail, which makes a very nstructive problem. In addition we have 1 ujj briefly the ordinary construction for an enclosed body. This will be especially ginner, as it will give him a better insight onstruction. ecided upon the side view, turn-under and body, we will proceed to lay out the shut pillar. The bevel of the pillar where the d be made to conform as much as possible face of the lock. From this point to the bevel is the same. I lines II. III. IV. Y and VI, Fig. 1, and m lines 2, 3, 4, 5 and 6, in Fig. 3. Deter- lius the door will swing to open at sections it 5 the bevel is the same as that on the ill open without any trouble, but we cannot on the pillar below section 5, as the turn- )or opening farther away from the center jessitating a greater bevel in order to have ' trying the shut bevel at each section in iiiel points it will be found that the greatest e bottom of the door. Set the trammel lie rear outside edge of the coupe pillar in ion, and describe an arc cutting the inside and outside edges of the door, and connect intersections with a straight line, thus establishing the bevel on which the door will open at each section. In order to obtain a perfect fitting door, the lock pillar and coupe pillar must be worked off to these different bevels, causing the inside face of the coupe pillar to be on a twist below the lock. Notice that the bevels of the coupe pillar are worked each time from the rear outside edge of the coupe pillar. This gives us a straight line for the front of the door and rear of coupe pillar in Fig. 1. Referring to Fig. 3, A, B, C and D are points on the outside of the coupe pillar at sections 2, 3, -i and G. Points a, b, c, d are points on the inside of the coupe pillar at corresponding sections. From the door line to the inside of the coupe pillar same should be rabbeted out ^4 "i^li to allow for the trimming. This is shown on Fig. 1 at sections II, III and IV, also on Fig. 4 at section YI. In connection with Figs. 2 and 4 we have shown the header, which should be securely framed into the coupe pillar by means of a mortise and tenon joint, as illustrated in section 10. p in Figs. 1 and 4 represents the head rail or roof rail, into which the coupe pillar should be framed b\' means of a mortise and tenon joint, as illustrated more clearly in Fig. 2 and section 10. Between the two coupe pillars there are two drop windows which require a center post. Figs. 5 and 6. This center post Practical Problems for Vehicle Draftsmen and Mechanics. ^ w ig Kl THE LAVING OUT OF A COUPfi PILLAR AND CONSTRUCTION OF FORWARD PART OF AN ENCL Peactic^vl Problems for Vehicle DRAExsiiEx and ]Mechanics. [NG OUT OF A COUPE PILLAR AND CONSTRUCTION OF FORWARD PART OF AN ENCLOSED BODY— Continued eader by means of a mortise and stump lapi^ed into the cross-bar i, Fig. 5. represents the neck-bar, Mhich is mortised r as shown in Fig. 2. Sometimes it is ) this into the coupe pillar. 5, represents the garnish board on the nd on to which is secured the trimming moulding. This should be in two pieces I give clearance enough for. and facilitat- the window frames. The garnish board 1 into the coujje pillar, and screwed, but and the garnish board k. Fig. 5. are ve the lining boards 1 and m, w^hich are I to the cross-bars i and g. Fig. 5. esents a post framed into the sill f and 1 post forms a bearing for the inside of h is secured to the same by means of glue In Fig. 5 we illustrate a light construction for the division window posts, that is, of fastening l^o-inch x l/^-inch angle brass to the bottom edge of the glass frame, and permitting one web of this angle to straddle the fence iron instead of having the complete frame to jump the fence, as is customary in most cases. By the use of this construction we lighten the division post in Fig. 5 at least % inch, or the thickness of the frame. p. Fig. -i, shows the roof rail rabbeted out to receive the roof board, which is usually of three-ply veneered stock, and should be glued securely and nailed frequently. Over this is glued the roof cloth, which should extend far enough outside of the roof to cover the joint between the roof board and the roof rail. Section V shows section of the coupe pillar neck-bar and garnish rails at the fence line. It will be noted that the garnish board k in section V is in two sections, and is swept so as to give clearance for window pull when the window is lowered or raised. .^Z^ ..^'y* ^^ T ^ •' >4 ■ '. ' .' ■ --^ Practical Problems for Vehicle Draftsmen and JNIechanics. The Framing Up of a Door and Pricking Off of a ( THIS ARTICLE supplements the laying out of a coupe j)illar and construction of forward part of an enclosed body. There are a great many different methods for framing up doors. Every bodymaker has his own ideas in regard to this subject. Let this article be intended more for the apprentice than for the experienced bodymaker. a and b, Fig. 1, represent the door pillars, a being the hinge pillar, and b the lock pillar. The thickness of the hinge pillar is 2i/8 inches, while that of the lock pillar is about 214 inches on the outside. These thicknesses are sometimes made more or less, according to the style and construction of the body, e and f are the top rails; g is the lock board; c and h are the fence and belt rails, respectively ; j is the lining board ; and i is the bottom board. In grooving out the door pillars for the glass frame runs, it is necessary that these be grooved out square, d is the bottom rail of the door, and is half-lapped into the lock and hinge pillars, the joint for the hinge pillar being shown at a and d. Fig. 7 shows two methods for framing the outside top rail e into the door pillars. Either method will be found practical. The joint used for framing the top rail e into the hinge pillar a is that of a bastard tenon. In framing the top rail e into the lock pillar b we use a stump tenon. The inside rail f is rabbeted into both pillars. Great care should be taken in framing the outside top rail e into the pillars, being sure to get a tight-fitting joint and as much stock outside of the tenon as practical. Fig. 3 shows a section of the door at the fence line, and the method used for framing ; into the door pillars. The feni pillars a and b. The lock boar( a and b. The belt rail h is als pillars. The bottom board i is ha a and b. In this construction it bottom side d into the door pilla all the strength required. Fig. 6, the section taken at shows the glass frame run and c laying out glass frame runs, ci plenty of clearance for the glas out sticking and at the same glass frames are % inch thick, wide at the fence and top and for clearance, and also paint. li width of the door jjillars at the the outside of the pillar to the wi 11/16 inch for the window seat plate, Yg inch clearance, another ] run, 1/^ inch more clearance, and «^ the width of the door pillars a in Fig. 6. Determine the length of tl project above the lower edge of about % or 7/16 inch, and lay frame run below the fence line glass frame or window to drop Practical Problems for Vehicle Draftsmen and Mechanics. THE FRAMING UP OF A DOOR AND PRICKING OFF OF A COUPfi PILLAR. Practical Problems for Vehicle Draftsmen and Mechanics. THE FRAMING UP OF A DOOR AND PRICKING OFF OF A COUPE PILLAI make this calculation so that about 1/4 or % inch of the top frame of the window will show above the fence plate, although in some cases it is impossible on account of the conditions of the chassis, sometimes necessitating cutting the corner of the door, which prevents the Avindow from dropping clear down. At the lower end of the glass frame run in Fig. 6 note that the run is 11/16 inch wide, and parallel for a short distance. This causes the window to fit closely at the bottom, and pre- vents chattering at this point. The glass frames should never come in contact with the window runs, there usually being screwed channel rubbers on the ends of the frame which work up and down in the runways. There should be plenty of clearance between the door bars, lock board, lining boards and the glass frames. As there is usually attached a strap to the bottom of the glass frame for raising the window, it is always advisable to sweep the lock board g in Fig. 3, which gives clearance for this strap and fixture. Set the lock board and lining boards so that they may be easily removed in case of any interference on the inside of the door. The lock board should not be glued to the pillars, but just screwed, and the joints should be well jjainted. Always give the runways a coat of linseed oil or primer as soon as possible. Referring to the framing up of the top and fence rails, we advise that the rails be recessed or set under 1/16 inch, as shown in Fig. 6, thus breaking the joint. These are a few general instructions and hints which may apply to the framing up and construction of any high door, but should not be regarded as fixed rules. With reference to the i>rickin is shown in Fig. 5 at A. Fig. pillar, and B is the top rail. C represents a section of the coupe bevel throughout. In getting out a coupe i)illar a to bottom, that is, beveling the pill from the outside of the pillar bef( causes the coupe pillar to be hea\ a simple method for getting the s and has been employed in carriage of the body was not very great where the bodies are a great dea turn-under, it is not found as s explained in the problem for lay construction of forward part of i as it produces a curved line pass d, e and f. Fig. 5, which causes the bottom than it is at the top. In jjricking this pillar off, la; I, II, III, IV, V and VI throng amount of turn-under at each sec out on Fig. 4., passing through t pillar. Wherever these sections a, b, c, d and e. Fig. 4, project corresponding sections at a, b, c, necting these points gives us the lii pillar and door. Practical Problems for Vehicle Draftsmen and Mechanics. The Construction of Glass Frames ■al may be said in regard to the construc- s frames, but in this article we will treat iry construction, which, like any part of a 1 ui)on the judgment of the mechanic, its an assembled glass frame, a being the back, c the top, and d the front. The ed without injury to the frame, omplish this it is necessary to leave two of In this case we leave the lower joint in tlie i the upper joint in the right hand corner me will be in two pieces. If all the joints , and anything hapiiened to the glass that s'ould be almost imijossible to reset a new le. As it is constructed here, this can be without injuring the frame in any way. :' the frame is rounded off as shown in me should be mitered at the inner corners , illustrated in Fig. 1. . 1, show the lower part of the front piece show the shape of the tenon which is let le bottom piece al. The same kind of a corners except the round corner, and this bare-face mortise and tenon, bl and b2, ower end of piece b. It also shows the . al and a2 show a part of the bottom nortised to take the tenon on the back the shoulders run horizontally on the lower ent raising and lowering of the window causes considerable strain on these lower joints, and in con- structing them this A\ay they are much stronger and there is less liability of the joints opening up. If the shoulders were vertical on the lower frame, all the strain would be on the tenons, and the joints would be more liable to open. Notice that the tenon on dl in Fig. 1 is cut on an angle, which is also true of the tenons on the top piece c. Another way for constructing the joint at the round corner or joining the two pieces a and b is shown in Fig. 2. In this method we mitre the two pieces together and unite them with a false tenon. This joint is frequently used, l)ut is not as reliable as that shown in Fig. 1 because it shows a longer joint and there is more liability of the joint opening. Fig. 4 represents a section of a glass frame which is rabbeted out to receive the glass. The rabbet is made deep enough to allow for a moulding which is fastened on the inside of the frame to hold the glass in place. Using this construc- tion it is possible to glue all joints in the frame, as the window glass is fastened and held in place by means oi' tlie moulding b. Referring to Fig. 3, b shows a section of the glass frame grooved out to receive the glass f. In using this construction there should be placed between the glass and the frame a thin strip of rubber, as shown by e. This holds the glass tight in place and jirevents rattling, which is sometimes the case when the glass is not of uniform thickness and the glass frames are grooved out uniformly. This rubber is shellaced to the glass. Sometimes nothing but jjutty is used for setting the glass, but, if rubber cannot be procured, we believe felt will be found to give satisfaction. Practical Problems for Vehicle Draftsmen and Mechanics. I Fis- 2 THE CONSTRUCTION OF GLASS FRAMES. Practical Problems for Vehicle Draftsmen and Mechanics. THE CONSTRUCTION OF GLASS FRAMES— Continued fly of the method for setting the glass frame . 3, represents the door j^illar grooved out )n the end of the glass frame is screwed The plate d is usually set inside the channel [■rews are put in from the inside and through channel rubber c should fit closely into the in the jiillar a. Fig. 3, and the glass frame itself should not come in contact with the glass frame run. Glass frames are usually made of mahogany, and the finish is important; therefore pains should always be taken to obtain perfect fitting joints, and the best of judgment should be used in the construction of the joints, for which there is no law laid down, but the foregoing are simply some practical hints on construction which has proven very satisfactory'. Practical Problems foe Vehicle Draftsmen and Mechanics. The Laying Out of a Wheel-house and Rear Mud IN A BODY which is especially wide across the rear seat it is often necessary to make a wheel-house, or depression in the side of the body, so as to give sufficient clearance for the rear wheel. In this event the rear mud guard usually fits into or close to this wheel-house, and conforms somewhat to its shape. We will first take up the method for laying- out the wheel-house in a body, such as illustrated. Lay out the j^rofile of the wheel-house and mud guard on the side view of the body. Fig. 1. On the rear view, Fig. 4, determine the amount of clearance necessary between the body and the wheel, and lay out inside line of wheel-house t-q-x. From Figs. 1 and 4 we will lay out the wheel-house on the bottom view in Fig. 2. On Fig. 1 lay out on the profile of the wheel-house, points 2, 3, 4, 5, 6 and 7, arbitrarily, and by means of the proportional scale in Fig. 5, lay out sections in Fig. 2 taken at heights of points 2, 3, 4, 5, 6 and 7 in Fig. 1. Squaring these points from Fig. 1 on to sections in Fig. 2 will establish points through which the outside of the wheel-house line r must jjass. The inside line of the wheel-house t should be taken from the section of the wheel-ouse at t on Fig. 4, and transferred on to Fig. 2, where it will show as a horizontal line. Wherever the outer line of the wheel-house intersects the inner line at the front and rear, numbers 1 and 8, Fig. 2, square down points intersecting the profile of the guard, estab- lishing points 1 and 8 in Fig. 1. Lay out horizontal section lines 10, 11 and 12 on Fig. 1. By means of the proportional scale. Fig. 5A. lay out these sections through the inside line of the wheel-house t on Fig. 2, and inside line of the wheel-house t dro they strike the corresponding sectio these points 10, 11 and 12, with 1 the bottom line of the wheel-house where the surface of the wheel-hou of the body. It will be seen on Fig. 2 that % inch wide around the top of the be set into the wheel-house level acr a bearing for the nmd guard. The wheel-house and is seem-ed at this le( In Fig. 6 we have the turn-unc the turn-under sweep at correspondi Fig. 2. Fig. 3 is the turn-under j round corner on the side at A, Fig- After this much is understood i a simple matter it is to lay out th necessary to lay out the profile of Fig. 2 the inside line s of the ledg rejjresent the inside line of the guar- 1 and 8. Determine the width of t lay out inside line of same in Fig. g of the body at 9. Connecting 8 an( of the guard, Fig. 8, as far as 1. closely the side of the body until it re frame. From this point until it joi usually cut away for the spring or b Practic.vl Problems for Vehicle Draftsmen and ]\Iechanics. 'f f 9 4 9(9'^*" / c d e ^ a A- A ^ K .f. y\~^ ^^ ( Practicai. Problems for Vehicle Draftsmen and jSIechanics, ng Out Pattern of Panel for a Metal Seat by the System of Triangulation ^TIOX is a system for measuring uy) and surfaces for the purpose of obtaining pat- leet metal work, and has long been used for leet metal workers and cornice makers. It ;he automobile and carriage trade in making ; with straight flares, but cannot be used on ivex or concave both ways, or, in other words, e to be hammered. For a convex or "King this system would be of no use, but for a as illustrated herein, or for nuul guards, ly ])anels, etc.. it is invaluable, inasmuch as md expense of setting up temporary forms desired patterns. the illustration. Fig. 1 is the elevation of a seat, and Fig. 2 is one-half the bottom view. ;wo views that we obtain the pattern of the g out the pattern of the seat it is necessary le of the arm rail in Fig. 2 as it drops down i seat. Space off on the top line around the 3, 5, 7, 9, 11 and 13. Fig. 2, commencing starts to round at the back, and continuing IS shown. Space off as many parts equally Fig. 2, connecting these points on top and leat with straight lines, project same points and lines on to corresjjonding positions in Fig. 1. Wherever the arm rail line on the profile intersects the oblique lines con- necting top and bottom points of seat, Fig. 1, project these points on to the corresponding lines in Fig. 2. For example, take point VII on line 7-8, Fig. 1, and project horizontally until same strikes line 7-8 at VII in Fig. 2. thus establishing a point through which the arm rail in the bottom view must pass. Lay out the triangles from these points on the arm rail and points on the seat bottom on Figs. 1 and 2 as shown. In starting the pattern, Fig. 5, lay out the center line OQ, which is equal to the full height on the flare of the seat at the back. Fig. 1. With the dividers take the distance from Q to 1 on the top line of the seat. Fig. 2, and transfer on to the pattern, using this distance as a radivis, and swing it out both sides of the center line from Q. In order to find the intersection of point 1 on these arcs, proceed as follows: Use the distance from () to 1 in Fig. 2 as the base of a triangle, and lay same off on any convenient space on the drawing, as Fig. 4, O to C. Taking the height of the seat perpendicularly from the bottom to point 1 at the top as the altitude or jjerpendicular, lay out on tlie triangle chart in Fig. 4, C to 1. Connecting C) with 1 in Fig. 4 will give us the hypothenuse of the triangle or the true length of line Practical Problems for Vehicle Draftsmen and Mechanics. LAVING OUT PATTERN OF PANEL FOR A METAL SEAT BY THE SYSTEM OF TRIANGUL Practical Problems for Vehicle Draftsmen and Mechanics. »ATTERN OF PANEL FOR A METAL SEAT BY THE SYSTEM OF TRIANGULATION— Continued listance should be laid out from O on Fig. 5 lie are drawn from Q at 1. nt 2 on jjattern, take distance from O to 2, off as a radius from O, F^ig. 5, both sides ke the distance 1 to 2, Fig. 2, as a base of a t off on Fig. 4 from C. Connect 1 and 2 36 or the true length of the line sought, and rom point 1, Fig. 5, until it intersects the at 2, and so on until the arm rail commences ter 3 on F'ig. 2 we cannot take the spaces line direct, as same is dropping until it runs line at XIII. pace the toji line of the arm rail correctly t on Fig. 5 it is necessary to lay off another obtain the true length of lines between 3 and ?h is done as follows : line 3 to V, Fig. .5, take the space from 3 ay it off from C on Fig. 6 as the base of a e amount that the arm rail drops, from 3 to ay it off from C on vertical line as the alti- tude, Fig. 6. Connecting 3 and V will give us the hypothenuse of the triangle c3V, Fig. 6, which is the true length of line 3 to V, Fig. 2, and should be laid off from 3 on Fig. 5. The same operation is necessarj' for every space on the arm rail between V and XIII, laj'ing out each triangle to obtain the true length of each line. As the points on the arm rail after 3 are getting lower it is necessary to change the altitude of each triangle on Fig. 4. Take the distance from 8 to IX, Fig. 2, for example. LTsing line 8 to IX as a base, lay this distance out on Fig. 4 from C to 8. Take the ijcrpendicular height of IX on Fig. 1 from the seat bottom and lay it out as the altitude. Fig. 4. Connecting 8 and IX, Fig. 4. will give vis the hypothenuse of the triangle or the true length of line 8 to IX, Fig. 2, which should be laid out from 8 on F"ig. 5 until it intersects the arc drawn from VII at IX. Continuina- these ojierations with all the points as shown will give us the outline of the pattern. Fig. 5. Around this pattern whatever flanges are necessary for turning under the seat frame and railing, etc., niav be added. Practical Problems for Vehicle Draftsmen and Mechanics. Laying Out of Pattern for a Shroud Pane THE SAINIE system of triangulatiou is applied in this problem for obtaining the pattern of a shroud as was used for working out pattern of the metal seat panel. The elevation and front view of the shroud. Figs. 1 and 2, are iirst laid out. Then on Fig. 2, the front view of the shroud, space off points on inner and outer lines as indicated by luuiibers. The location of these points is not fixed by any rule, but good judgment should be used in placing them Avhere necessary only, the corners being the parts where the spaces should be laid out most frequently in order to insure the most accurate results. The flat or nearly flat surfaces do not require as many triangles. Connecting the points on the inside and outside lines of the shroud in Fig. 2 will establish the triangles with which we will lay off the full pattern of the shroud in Fig. .5. Lay out the full length of line 0-Q on the center of the pattern, Fig. 5, as taken froiu Fig. 1. In spacing off the points on the l)ack line of the pattern in Fig. 5, do not take the distances direct from the outer line on Fig. 2, as these spaces do not represent the exact length of the lines, as well be seen by looking at Fig. 1. The rear line of the shroud slants back toward the bottom. Therefore lay off triangles for each s^sace separate, as in Fig. 6. For example: In spacing off point 1 in iiattern. Fig. 5, take the distance from 1 to Q in Fig 2, and lay it off as the base of a triangle on line a-a. Fig. 6, from Q. Take the dis- tance that the shroud slants back, Q to 1 in Fig. 4, and lay it out in Fig. 6 from line a-a to ] triangle. From Q to 1 in Fig. ( the true length of the line Q to swung off both sides of Q in Fied colors are white, brown, blue, green, yellow, iid dee]) gray, but, of course, by buying a whole re in the box that may be needed. India ink in i a necessity. Some prefer Higgins' American make, while othei's prefer the French make, but both are of excellent quality. Pen drawings, uncolored or colored, should not be drawn directly on bristol board or any other kind of drawing paper, but should be made either on thin white pai)er or the regular tracing paper. Mistakes in outlining carriages and automobiles are unavoidal)le, and, therefore, must he erased, and the surface of the very best drawing paper that is made will be damaged with the eraser, and defects show through the colors. After the sketch is done, it is blackened on the rear side, that is, the reverse side from the drawing. For this, dry lamp black is used. Others save the dust from the pencil sharpener. To obtain the dust, they use a small box with a fiat file on to]). The file is used as a pencil sharpener, and the dust drops in the box, and is kept in the box until needed. ^lost artists use I'ed chalk known as "rouge." Some of the black dust will adhere to the paper where not wanted, and it is difficult to remove it, while the rouge is more easily erased. When the sketch is finished and reddened on the rear side of tracing paper, it is put on the bristol board, fastened with thumb tacks, and all the lines are then gone over with a 6-H Faber or Hardtmuth pencil with a sharp point. Others use a needle or tracer, which will be found among the drawing instruments. By this process, a clean, correct reproduction of the design is obtained, and at the same time the draftsman has a copy for future use. The foreground of the object nmst be drawn first, which, on a carriage or automobile, means the wheeN on the near side. Each object or part of the vehicle is thus drawn, one after the other, and the last part to be drawn will be the off wheels. At the same time, the required colors must always be kept in mind. If the gears are yellow, and strijied black, the face of the spokes near the hubs have genei'ally two fine black lines, also one or two fine black lines on the rim faces, and tires black. In such a case, the hubs, spokes and rims are colored first, and black lines drawn on top of yellow, and all colors are worked same as India ink. I^r making small lines on gear or body, also Practical Problems for Vehicle Draftsmen and Mechanics, COLORING CARRIAGE AND AUTOMOBILE DRAWINGS— Continu scrolling, use a lady's pen. In fact, a lady's pen is very handy for all kinds of lines, even the straight lines. Ijines of various thicknesses can lie made by more or less pressure, thus avoiding the unscrewing of drawing pens. Working with a lady's pen requires considerable jiractice, but, when once mastered, it is a great advantage, and consider- able time is saved thereby. A colored i)late can not be made except all the outlines are drawn with the required color of the ink. If the gear is yellow, the outlines must be of the same color, and if the body is blue, the outlines are blue, if the colors are of a darker shade. Otherwise, if a light shade, the outlines reiinire a fine black India ink line. To start the color on bodies, if there is black, such as rockers and boot panels, use Winsor and Newton's lamp black, to which, after being rubbed up to a lather thick li(|uid. add a very little dissolved gum arabic. To know whether the color has the proper consistency when rubbed n\), tip the cup. If right for use, the color must flow slowly. To make all outlines sharp, run them over twice with lamp black with the drawing pen, and fill the rest of the panel between the lines. For the small and narrow black spaces, thin down the color somewhat, otherwise it will have a too heavy appearance. For the rest of the panels, that is, the large spaces, the brush is used, but care must be taken to distribute the color ]iroperly. The i^ainting of the body in coach l)ody colors is exceedingly difficult, and requires considerable practice, as very few of the water colors have sufficient Iiody to cover well. Lanq) black. Prussian blue, vermilion and Indian are the only ones having good coloring jn-operties. Most artists require transparent colors, while for carriage, coach and automobile work they must cover the surface at the first stroke, as only a few colors will allow a second coat. Carmine and ultramarine are the only ones, and it requires great care and considerable ]n-aetiee to ])roduce a uniform surface after several coats. Perfect work cannot be produced with imperfect colors, bu made just for this work, which cov application, can be bought in first-cl Colors of this kind must be rul ency as exi)lained for lamp black, freely, l>ut with extreme uniformit not be retouched, as it will show de The striping, which gives finish ing, is used either to cover the edges, and is done with the drawing pens, lady's pen, and one that has been u used, as a new pen is too sharply i)oi colors. The colors for striping are milion, white, yellow, orange, cliron a combination of the above colors. After the striping lines have b( body, prepare lamp black, which flow very fine line under, or right and lef senting the shade for the striping they are tufted ; lower part darker a part can lie imitated from clear, well tone illustrations. Make handles, . or gold, but as these are generally ))ared to be suitable for this work, it into a saucer, and allow it to stan water which rises to the surface, a arabic gum water, stir well, and aj dry, burnish with a thin bone with ro burnt sienna. A great deal more could be sai( above exjilauation is about the whole order to be successful, do not mind greatest care and the very best ma essential points. Practical Pkoblems for Vehicle Draftsmen and ISIechanics. Working Drafts )WING working drafts represent nearly every utomobile l)odies, and shonld be of great service -rence for designs, etc. Tliey are accurately king scale. The different views are kept clear which makes them easy to follow, ^ly, on account of having to make shop working it is necessary sometimes to lay out one view on \ge draftsmen and men who can lay out and from the draft are in good demand, and are jiaid men in the trade. to make a comj^lete working draft of a carriage ody requires considerable skill and experience. )eginners is to practice free-hand drawing and ;o obtain good, true lines, not dei)ending on lods. Scale drawing is very good practice, nee obtained by practical work in the body shop ^his will give the student a better understanding ion recjuired on a draft. ns taken up in this book should be thoroiighly as to be alile to apjily them correctly. Aim to as plain and simjjle as possible, putting on only orking lines, as any unnecessary lines confuse well as waste the draftsman's time, ions and connecting lines shown in the problems his book should not be on the working drawing, ■ded to obtain the desired points, they should ■emoved. They are shown in the prolilems for I it is sometimes better to work out the problem per separate from the working draft, and make opiate of the line obtained and transfer same to ift, thereby obviating the erasing of lines and ■face of the draft. working draft the base line of the body is gen- the center line of the half bottom view, therefore es of the half liottom view must be drawn on levation. This is ai)t to confuse a beginner, and is one of the reasons for our caution against putting on unnecessary lines. Before one can make a working draft of a liody, he must have a general idea in his mind of what he is to draw. It is best to first make a small scale drawing, or put the design on a blackboard, where it can be looked over and changed if desir- able. The proportions of a vehicle can be studied better from a blackboard. Special attention should 1)e given to the full-size draft lioard and tools for making a draft. Well-seasoned soft jiine is the best material for the board, which should be made large enough for the full size of the body. The board should not be less than ZW thick and jointed and glued u}) well. Hardwood cleats should be ])laced under the board, not fastened directly to it, but so as to allow the boards to ex])and and contract without wari)ing. Have all edges planed off scpiare. This is very im])ortant to insure accurate work. If the draft board is made so that it can tilt at any angle, it is more convenient. The best of drawing instruments, squares, triangles and curves are necessary. It is also desirable to have a bench and vise at hand, so that the different patterns or sweeps may be made as desired. In making these patterns or sweeps, great care must be taken to get them smooth and true, vising the eye to ascertain, by sighting along the edge of the sweej). It is customary to lay out the near side of the body or the left side elevation first. Outline the body in all views as nmcli as possible, and then fill in the detail and construction. Always aim to keep the body as light in weight as possilile, consistent with strength, as unnecessary weight in the construction of any vehicle is undesirable. Provisions should lie made to accommodate locks, hinges and other hardware. The ironing and trimming should also be considered. And so we could go on indefinitely giving advice, ])ut most of these things must be learned l)y experience. So we advise the beginner to "stick to it" and put forth his best effort in all things. Perseverance and careful work will lead to success. Practical Problems for Vehicle Draftsmen and Mechanics. J4ai/ Bck<:Ji dCevaCum 7-S JncA &<,