When you have completed this lesson, you will be able to:
|
1.0.0 Work Preparation
2.0.0 Basic Drafting Techniques 3.0.0 Drawing Formats 4.0.0 Line Conventions 5.0.0 Order of Penciling 6.0.0 Order of Inking |
7.0.0 Lettering
8.0.0 Inclined Lettering 9.0.0 Composition of Lettering 10.0.0 Mechanical Lettering Summary Review Questions |
Before you begin to work, devote some time and thought to organize your working area. Arrange your drafting furniture so you can work comfortably without fatigue or eyestrain. Be sure to check the lighting before you set up your drafting table. Devise a system of stowing your equipment and supplies so they are handy and in order.
Your immediate work area should be large enough to allow sufficient freedom of movement but not so large that you waste time reaching for equipment, supplies, and reference publications. An ideal working area allows each draftsman approximately 90 sq ft of space, although you may actually have more or less depending on the total area of the drafting room and the number of draftsmen who will work there. If you are easily distracted, do not butt your drafting table up against and facing another draftsman’s table. Ensure that you have adequate lighting. The best light for drafting is natural light coming over the left shoulder and from the front left to avoid shadows cast by your hands, T square or parallel ruling straightedge, and triangles. Avoid glaring light as it will cause eyestrain. Use a drafting lamp if necessary. Your drafting table height should be from 36 to 40 inches above floor level.
Your drafting chair or stool should be high enough that you can see the whole drawing board, but not so high that you have to lean over uncomfortably to draw. You may adjust your board at an incline or leave it flat according to your preference. A slope of 1 to 8 works well for the inclined position. By shifting your body or head slightly, you should be able to look directly at any point on an average-sized drawing sheet; that is, your line of sight should be approximately perpendicular to the drawing surface.
Before you begin to draw, arrange your equipment in an orderly manner. Place each article so that you can reach it easily, and keep it in place when you are not using it. A systematic arrangement is timesaving and efficient. Keeping your tools in order decreases the likelihood of accidentally dropping them or pushing them off the table. You will find it very convenient to have a small worktable adjacent to your drafting board. Placing your drafting tools and reference publications on the worktable leaves you with an uncluttered drawing board surface. When you use the drafting board in the inclined position, a separate worktable becomes a necessity. You will select the drafting equipment and materials according to the needs of each of your drafting assignments. Let your good judgment and common sense guide you in their selection. After some experience, you will automatically select proper equipment and materials as they are required. Until you become proficient, don’t hesitate to seek the advice of your drafting supervisor or an experienced draftsman. You will be exposed to modern drafting equipment, materials, and software as you are assigned to staff and support billets within the Naval Construction Force (NCF).
As a Seabee draftsman, you will probably not be able to select your drafting board. Unless the board is new, it will probably be marred and full of small pinholes. To obtain a smooth drawing surface, cover the board with a vinyl material or heavy manila paper. Laminated vinyl covering minimizes pencil scoring, reduces glare, and is easily kept clean by wiping with a damp cloth. Heavy manila paper will serve the same purpose, but must be replaced when it becomes soiled or marked with use.
You will prepare most of your drawings on tracing paper. You will use tracing paper to copy or trace drawings either in pencil or in ink. You will also prepare most of your original pencil drawings on tracing paper. This type of paper is especially suited for reproduction of blueprints; however, it tears easily and becomes soiled after repeated handling.
When making a drawing directly on tracing paper, place a smooth sheet of white paper below it (detail paper works well). The whiteness of this sheet (called a platen sheet) gives better line visibility, and its hard surface enables you to draw good pencil lines without grooving the tracing paper. Do not use gritty erasers on tracing paper, especially if you are going to apply ink later. If you must make erasures, use a green or red ruby eraser, which is only slightly abrasive. Abrasive erasers wear away the surface. Erase carefully so you don’t tear the drawing. A light back-and-forth motion works best. If the surface of the drawing becomes scratched by erasing, it can be partially smoothed by burnishing the damaged area with a hard, smooth object or your thumbnail. Avoid using the electric eraser on tracing paper, as it will quickly “burn” a hole through the paper. To clean up smudges and dust, use a soft art gum eraser or sprinkle pounce on the drawing and rub lightly with your hand or a triangle. Water, perspiration, or graphite from your pencil will ruin drawing paper. In order to keep moist hands or arms from marring the drawing, use a clean sheet of paper as a mask to protect the drawing surface next to the work area. Between drawing sessions, protect unfinished drawings by covering them.
Do not fold tracing paper. The crease marks will damage the lines on the drawing and cause blurred prints when the drawing is reproduced. For that matter, you should never fold any drawing. Drawings and tracings should be either stored flat or rolled and placed in cylindrical containers. The exception to this rule is that prints or drawings larger than 8 ½ inches by 11 inches may be folded so that they can be filed in standard filing cabinets.
Besides tracing paper, you will select other types of paper for special uses. You will mainly be concerned with the gridded papers. You will use gridded paper of a quality similar to that of tracing paper and should handle it in the same way. As you gain experience, you will learn which type of paper to use for each drafting assignment. Of course, you will be limited by the types of paper available and the guidelines given to you by your drafting supervisor.
For the average drafting assignment, you will use three or four pencils. You should use a hard pencil, 4H or 5H, to lay out the drawing in light construction and projection lines. You will then use a medium pencil, H or F, to darken the required lines and to make arrowheads and lettering. Base your pencil choice on the grade of drawing paper you use. A soft, rough-textured paper usually requires a softer pencil for layout work, since a hard pencil would leave indentations in the paper and thus spoil the appearance of the drawing.
One way to find out if you are using the proper pencils on a drawing is to make a blueprint (reproduction) of the drawing. If the reproduced lines do not appear, or appear too light, use a softer pencil. If, on the other hand, lines appear too dark in relation to other lines, use a harder pencil. You may be able to vary the weight of lines by the amount of pressure exerted on the pencil, but do not attempt this without experience. Bearing down on a hard pencil to produce darker lines may cause grooves in the paper.
Another way to find out if you are using the proper pencil is to hold your drawing up to a light and view it from the back side. Pencil adjustment is the same as in the previous method. Of course, both methods apply only when transparent drawing paper is used.
To sharpen a pencil, cut the wood away from the unlettered end (Figure 4-1A) with a draftsman’s pencil sharpener or a penknife. The lettered end should be left intact so that the grade of pencil can always be identified. The cut should be started about 1 1/2 inch from the end, leaving half an inch of lead exposed. To produce a conical or needlepoint (Figure 4-1B), which is best for general use, rotate the pencil between the fingers at the same time as the exposed lead is rubbed back and forth across the full length of the sandpaper pad (Figure 4-1C).
Figure 4-1 – Sharpening pencil points.
Many draftsmen prefer to use a mechanical lead pointer instead of the sandpaper pad. The mechanical pointer quickly produces a uniform conical or needlepoint. However, other types of points still require the sandpaper pad. The resulting needlepoint should be dulled slightly by drawing it lightly across a piece of scrap paper several times. Avoid sharpening pencils near your drawing. Graphite particles will cause smudges that are difficult to erase. Use a cloth or tissue to wipe away graphite particles that cling to the pencil after it is sharpened. A wedge point (Figure 4-1D) will aid an experienced draftsman in the extensive drawing of straight lines. This point is produced by sharpening a pencil to the conical point just described, then flattening both sides on the sandpaper pad. For an elliptical point, hold the pencil firmly with thumb and fingers and cut the lead on the sandpaper pad by a back-and-forth motion, keeping the pencil at an angle of about 25 degrees to the pad. Continue until a flat ellipse is formed, as shown in Figure 4-1E. A good draftsman never uses a dull pencil.
Some draftsmen prefer to use mechanical drafting pencils instead of wooden pencils. The lead of a mechanical pencil is sharpened in the same manner as the lead of a wooden pencil. However, the length of the mechanical pencil is not depleted as the lead is sharpened. This is an advantage over wooden pencils that become difficult to use when they are less than 3 inches long. When changing leads for the mechanical pencil, ensure that the changeable lead grade designator on the mechanical pencil corresponds to that of the lead used.
Always practice handling and using drafting instruments before attempting complex drawing problems. You will continue to make improvements in the quality of your drawings by developing correct drawing habits. The main purpose of making your first drawings is to learn to use instruments. Each drawing will offer an opportunity for practice. Later on, good form in the use of instruments will become a natural habit.
Accurate pencil drawings are of the first importance since all inked drawings and tracings are made from finished pencil drawings. You cannot correct a poor pencil drawing when you make the ink tracing. Any drawing important enough to be inked or traced in ink must be accurate, legible, and neat. Because you will prepare most military and commercial blueprints from pencil drawings, you should work to hone your pencil drawing technique. Good technique and skillful pencil drawing are basic to proficiency in drafting.
The following sections guide you in attaching your drawing paper to the board and in drawing basic lines with the T square, triangles, and pencil.
Once you are relatively familiar with your equipment and materials, get started by attaching your drafting paper to the board. Place the sheet close to the left edge of the drafting board. Working in this area makes the T square easier to handle and reduces the likelihood of error because of T square “swing.” The drafting sheet should be far enough from the bottom of the board (about 3 inches) to ensure firm support for the head of the T square when you are drawing on the lower part of the sheet. Figure 4-2 shows a drawing sheet properly attached to the board on which a T square is used.
Figure 4-2 – Attaching drafting paper to the board.
After aligning the drawing sheet, smooth out any wrinkles and fasten the four corners with short strips of drafting tape. If you are attaching large sheets, place additional strips of tape at the top and bottom edges of the sheet. Drafting tape has a lighter coating of adhesive than does masking tape and will hold the drawing firmly, yet it can be removed without tearing or marring the drawing. If you use masking tape or transparent tape, leave a large margin in the event you tear the paper when removing the tape. When placed diagonally across the corners of the sheet, as shown in Figure 4- 2, drafting tape offers little obstruction to movement of the T square and triangles. Avoid the use of thumbtacks; they will eventually ruin the drafting board. If you are using a parallel straightedge or drafting machine instead of a T square, the procedure just described is the same with one exception. Instead of placing the paper close to the left edge of the board, place it approximately at the midpoint of the length of the parallel straightedge or in the center of the drawing board surface when you are using a drafting machine.
As a draftsman, you will construct a horizontal line by drawing from left to right along the working edge of a T square, as shown in Figure 4-3.
Figure 4-3 – Construction of a horizontal line.
This working edge, when true, is perpendicular to the working edge of the drafting board. When you draw horizontal lines, keep the working edge of the T square head in firm contact with the working edge of the drafting board. Incline your pencil to the right at an angle of about 60 degrees with the point close to the junction of the working edge and the paper. Hold the pencil lightly and, if it was sharpened with a conical point, rotate it slowly while drawing the line to achieve a uniform line width and preserve the shape of the point. Normally, when you are drawing a series of horizontal lines, start from the top and work your way down
You will create vertical lines parallel to the working edge of the drafting board by using triangles in combination with a T square. Place one leg of a triangle against the working edge of the blade so that the other leg faces the working edge of the board to prevent casting a shadow over your work. Draw lines from the bottom up, as shown in Figure 4-4.
Figure 4-4 – Construction of a vertical line.
Incline your pencil toward the top of the working sheet at an angle of approximately 60 degrees, with the point as close as possible to the junction of the triangle and the drafting paper. When drawing a series of vertical lines, start from the left and work your way to the right. Never use the lower edge of the T square blade as a base for triangles.
Measure the direction or angle of inclination of an inclined line on a drafting sheet in reference to the base line from which it is drawn. Inclined lines at standard angles are constructed with the T square as a base for triangles used either singly, as shown in Figure 4-5A and B, or in combination, as shown in Figure 4-5C.
Figure 4-5 – Construction of an inclined line.
In combination with the T square as a base, use the triangles as guides for producing lines at intervals of 15 degrees, as shown in Figure 4-6. You can use the 45-degree triangle to divide a circle into 8 equal parts; you can use the 30°/60° triangle to divide a circle into 12 equal parts. For drawing lines at angles other than those described above, use a protractor.
Figure 4-6 – Using a T square (or parallel straightedge) and triangles to draw
lines at different angles to the horizontal.
Arrows indicate the direction in which the lines should be drawn.
To measure an angle, place the center mark of the protractor at the vertex of the angle, with the 0-degree line along one side, then note the degree mark that falls on the side. To lay off an angle, position the protractor as above and use a needlepoint or a sharp-pointed pencil to mark the desired values, then project lines from the vertex to these marks.
Using only the three points on the protractor, as described above, may result in considerable inaccuracy, particularly if you need to extend the lines of an angle for some distance beyond the protractor. Figure 4-7 illustrates a refinement of the procedure.
Figure 4-7 – Protracting an angle.
Suppose you need to measure angle BOA. Extend line AO on to C; extend line BO on to D. When you set the center of the protractor at O, make sure that both points c and a are on line AC. Take your reading at point d as well as at point b when you measure the angle.
If you are laying off the angle BOA, protract and mark point d as well as point b; this gives you three points (d, O, and b) for establishing line DB. If you are using a semicircular protractor, you can’t, of course, locate point d; but your accuracy will be improved by lining up c, O, and a before you measure or lay off the single angle BOA.
To draw a line parallel to a given line (Figure 4-8), adjust the hypotenuse of a triangle in combination with a straightedge (T square or triangle) to the given line; then, holding the straightedge firmly in position, slip the triangle to the desired position and draw the parallel line along the hypotenuse.
Figure 4-8 – Drawing parallel lines.
To construct a line perpendicular to an existing line, use the triangle and straightedge in combination, with the hypotenuse of the triangle resting against the upper edge of the straightedge (Figure 4-9). Adjust one leg of the triangle to a given line. Slide the triangle along the supporting straightedge to the desired position and draw the line along the leg, perpendicular to the leg that was adjusted to the given line. In the same manner, angles with multiples of 15 degrees may be drawn, using the triangle combinations shown in Figure 4-6.
Figure 4-9 – Drawing perpendicular lines.
You will prepare many drawings that require the construction of various curved lines. Basically you will draw types of curved lines: circles and segments of circles, called arcs, which are drawn with a compass; and noncircular curves, which are usually drawn with french curves. We will discuss only techniques for using the compass and the french curve. We will discuss the application of compass techniques in geometric construction later.
When you draw circles and arcs, it is important that the lines you produce with the compass are the same weight as corresponding pencil lines. Since you cannot exert as much pressure on the compass as you can with pencils, use a compass lead about one grade softer than the pencil used for corresponding line work. For dim construction lines, use 4H to 6H leads. Avoid using leads that are too short.
Sharpen the compass lead with a single elliptical face, as shown in Figure 4-10A. A sandpaper pad works best for sharpening compass leads. You will normally place the elliptical face of the lead in the compass so that it faces outward from the other compass leg. Adjust the shoulder-end needlepoint so that the point extends slightly farther than the lead, as shown in Figure 4-10B. Pressing the needlepoint lightly in the paper, center the compass vertically when the legs are brought together.
Figure 4-10 – Sharpening the compass lead and adjusting the point.
Use bow compasses and pivot joint compasses in the same manner. To draw a circle with a compass, lightly press the needlepoint into the drawing paper and rotate the marking leg around it. Always rotate the compass clockwise. As you rotate, lean the compass slightly forward. With a little practice, you will find that you can easily draw smooth circles using only the thumb and forefinger of one hand. It is important to use an even pressure as you rotate the compass.
You may find it necessary to rotate the compass several times to produce a circle with a uniform dense black line.
When you wish to set the compass to draw a circle of a given diameter, use a piece of scratch paper and follow the steps listed below, referring to Figure 4-11.
Figure 4-11– Drawing a circle of a given radius.
Once you have set the compass to the exact radius of the circle, handle it very carefully so that you don’t disturb the setting. Set the needlepoint at the center of the circle and carefully rotate the compass to draw a line describing the circumference of the circle. Do not apply too much pressure on the needlepoint or it will bore a hole in the paper and you will lose the accurate center mark. To minimize the diameter of the hole, set the needlepoint of the compass on a small strip of paper or thin cardboard over the drafting sheet at the center of the circle.
When you are using the pencil leg to draw circles smaller than 1 inch in radius, keep the adjustable pencil and needle legs straight. For larger circles, both legs should be adjusted so that they are perpendicular to the paper. On the other hand, when you are using the compass with the pen leg, you MUST adjust it at the hinge joint to keep it perpendicular to the paper for all size circles. (See Figure 4-12A.) If the pen is not perpendicular to the paper, ink will not flow properly. To draw large circles, insert the extension bar in the pen or pencil leg, as shown in Figure 4-12B. When the extension bar is used to draw large circles, the process of using the compass with only one hand becomes awkward. You should use both hands, as shown in Figure 4-12B.
Figure 4-12 – Drawing a circle in ink.
Use the french curve to draw a smooth line through predetermined points. After plotting the points, sketch a light pencil line to connect the points in a smooth flowing line. To draw the finished line over the freehand line, match the various parts of the french curve to various segments of the freehand curve. Avoid abrupt changes in curvature by placing the short radius of the french curve toward the short radius portion of the line being drawn. Change your position around the drawing board when necessary so that you can work on the side of the french curve that is away from you. Avoid working on the “under” side of the French curve. Place the french curve so that it intersects at least two points of the line.
When drawing the line along the edge of the french curve, stop short of the last point intersected. Then move the french curve along to intersect two or three more points and make sure that the edge of the curve connects smoothly with the line already drawn. When using the irregular curve, you can draw a perfectly smooth curved line by plotting enough points (the sharper the curve, the more points you need) and by drawing in shorts steps.
Figure 4-13 shows how a smooth line is drawn through a series of plotted points. The french curve in Figure 4-13A matches points 1, 2, 3, and 4. Draw a line from 1 to 3 only (not to 4).
Figure 4-13 – Use of the french curve.
At Figure 4-13B, the curve matches points 3 to beyond 4. Draw a line from 3 to 4 only (not to 5).
At Figure 4-13C, the curve matches points 4, 5, and 6. Draw a line from 4 to just short of 6.
At Figure 4-13D, the curve matches a point short of 6 to beyond 7. Draw a line from 6 to 7.
At Figure 4-13E, the curve matches a point short of 7 to beyond 9. Draw a line from 7 to 9.
At Figure 4-13F, the curve matches a point short of 9 to beyond 11. Draw a line from 9 to 11.
You will probably notice how the curve is turned over and reversed to find portions that fit the points on the line with increasing or decreasing changes in curvature.
When you are drawing a curved line that extends into a straight line, draw the curve first, and join the straight line to it.
Use drafting templates only when accuracy can be sacrificed for speed. For example, you can draw circles or arcs more quickly with a template than with a compass. Templates must be used properly to be effective. To draw a circle with the circle template (Figure 4-14), lay out center lines on the drawing where the circle is to be drawn. Then place the correct circle opening over the center line so that the quadrant lines on the template coincide with the center lines on the paper. Draw the circle, using a sharp, conical point on the pencil. Allowance must always be made for the width of the pencil line in placing the template opening in the right position on the drawing.
Figure 4-14 – Use of the circle template.
To draw an arc, lay out tangent lines on the drawing. Place the correct size circle of the template on the paper so that the template quadrant lines coincide with the tangent lines, and draw the arc. When using a template, you must hold it down firmly to keep it from slipping out of position. Be sure to draw figures or circles from the template with the correct line weight on the first setting, as it is difficult to reset the template in the exact position.
Use dividers to transfer measurements, to step off a series of equal distances, and to divide lines into a number of equal parts. Manipulate dividers with one hand. In setting dividers (Figure 4-15), hold one leg between the thumb and the first and second fingers, and hold the other leg between the third and fourth fingers. Place the second and third fingers on the inside of the legs; the dividers are opened by spreading these fingers apart. Close the dividers by squeezing the thumb and first finger toward the fourth finger while gradually slipping out the other two fingers.
Figure 4-15 – Holding a divider.
To transfer measurements on a drawing, set the dividers to the correct distance, then transfer the measurements to the drawing by pricking the drawing surface very lightly with the points of the dividers.
To measure off a series of equal distances on the line, set the dividers to the given distance. Step off this distance as many times as desired by swinging the dividers from one leg to the other along the line, first swinging clockwise 180 degrees, then counterclockwise 180 degrees, and so on.
In dividing either a straight line (Figure 4-16A) or a curved line (Figure 4-16B) into a given number of equal parts (for example, four) by trial, open the dividers to a rough approximation of the first division (in this case, one quarter of the line length) and step off the distance lightly, holding the dividers by the handle and pivoting the instrument on alternate sides of the line at each step. If the dividers fall short of the end of the line after the fourth step, hold the back leg in place and advance the forward leg, by guess, one quarter of the remaining distance.
Figure 4-16 – Dividing a straight line and a curved line.
Repeat the procedure until the last step falls at the end of the line. Be careful during this process not to punch holes in the paper, but just barely mark the surface for future reference. To identify prick marks made with small dividers for future reference, circle the marks lightly with a pencil.
Your drawing accuracy depends to a great extent upon correct use of the scale in marking off distances. Place the edge of the scale parallel to the line being measured (Figure 4-17). To eliminate shadows cast by your body or hands, point the desired scale face away from you for horizontal measurements and toward your left for vertical measurements.
Figure 4-17 – Use of the drafting scale.
With a sharp pencil, mark off short dashes at right angles to the scale at the correct distances, aligning the mark carefully with the scale graduation. Have your eye approximately over the point being measured and make light marks to denote the point of measurement.
When setting the compass to a given radius or when setting divider points, never place the sharp points of these instruments on the scale. Lay out the desired radius or distance on a straight pencil line by using the scale in the manner described above. Adjust the compass or dividers to the indicated length by using the measured line. A scale surface marred by pinpricks is difficult to read and unsuitable for accurate work.
In making successive measurements along the same line, make as many measurements as possible without moving the scale. If a number of distances are to be laid out end to end, hold the scale in one position and add each successive measurement to the preceding one. Moving the scale to a new position each time, may cause slight errors to accumulate. For example, four successive measurements of 1 5/8 inch each should give an overall length of 6 1/2 inches, not 6 9/16 inches. Therefore, make as many measurements as you can without changing the reference point. This will avoid cumulative errors in the use of the scale. Note that your pencil touches the scale only for the purpose of marking a point on the paper. Never use a scale as a straightedge for drawing lines. A typical office ruler has a metal edge; it is a scale and straightedge combined. But a draftsman’s measuring scale is for measuring only; it is not a ruler. A scale properly used will last for decades, but a scale used as a straightedge will soon have the graduations worn away.
Drawing format refers to the systematic space arrangement of required information within the drafting sheet. This information is used to identify, process, and file drawings methodically.
Most of the documents applicable to these standards have recently been revised and updated in order to gain like information and to share uniformity of form and language within the building professions. The current widespread use of both conventional and computer-generated, reduced-size copies of drawings and the exchange of microfilm and other media are other influencing factors for standards updates.
Standard drawing sheet sizes facilitate readability, reproduction, handling, and uniform filing. Blueprints produced from standard size drawing sheets are easily assembled in sets for project stick files and can readily be folded for mailing and neatly filed in project letter size or legal size folders. (Filing drawings and folding blueprints will be covered later in this training manual.)
Figure 4-18 shows finished format sizes for drawings that are, according to ANSI Y14.1(1980), approved and adopted for widespread use.
| Flat Sizes | ||||
|
Size Designation Letter |
X (width |
Y (Length) |
Margin | |
|
H (Horz) |
V (vert) |
|||
|
A (HORIZ)
A (VERT) BC D E F |
8.5
11.0 11.0 17.0 22.0 34.0 28.0 |
11.0
8.5 1 7.0 22.0 34.0 44.0 40.0 |
0.38
0.25 0.38 0.75 0.50 1.00 0.50 |
0.25
0.38 0.62 0.50 1.00 0.50 0.50 |
| NOTES: 1. ALL DIMENSIONS ARE IN INCHES | ||||
Figure 4-18 – Guide for preparing horizontal and vertical margins, sizes, and finished drawing format for flat drawings.
Drawings that are relatively small and should be stored or filed flat are referred to as flat size. Drawings that are long in length are filed in rolls and referred to as roll size. Finished format sizes for a drawing refer to the dimensions between trim lines (X and Y in Figure 4-18). The trim line is the outside line of either the vertical or horizontal margin. The inside lines of the margins are called borderlines. Width (X) is always parallel to the working edge of the drawing board; length (Y) is always perpendicular to the working edge of the drawing board.
Notice, in Figure 4-19, that you should add 2 inches to the left margin and to the right margin for protection of roll-size drawings. The edge of a drawing prepared on tracing paper will tear easily after it is rolled and unrolled several times.
| Roll Sizes | |||||
|
Size Designation Letter |
X (width |
Y (Length) |
Margin | ||
| Min | Max |
H (Horz) |
V (vert) |
||
|
G
H J K |
11.0
28.0 34.0 40.0 |
22.5
44.0 55.0 55.0 |
90.0
145.0 176.0 143.0 |
0.38
0.50 0.50 0.50 |
0.50
0.50 0.50 0.50 |
NOTES:
|
|||||
Figure 4-19 – Guide for preparing horizontal and vertical margins, sizes, and finished drawing format for roll drawings.
Sheets of drafting or tracing paper are cut slightly larger than their required finished sizes and are fastened to the drafting board as previously described. Using a hard (4H to 6H) pencil and a T square (or parallel straightedge), draw a horizontal trim line near the lower edge of the paper. Draw a vertical trim line near the left edge of the paper with a T square (or parallel straightedge), pencil, and triangle, as previously described. On the horizontal trim lines, mark off dimensions establishing the finished length of the sheet (distance between vertical trim lines) and the location of the vertical. Use a fullsize scale when you are laying off a series of measurements along a line. On the vertical trim lines, mark off the dimensions establishing the finished width of the sheet (distance between horizontal trim lines) and the location of the horizontal borderlines. Scale the dimensions along the borderlines.
After the drawing is completed, give the borderlines the required weight. After removing the completed drawing from the board, cut it to its finished size along the trim line. If blueprints are to be made on paper that is not precut to the standard drawing size, you may find it necessary to leave an extra margin outside the trim lines. By leaving an extra margin, you can darken the trim lines. The darkened trim lines, when reproduced, will provide a visible line for trimming the blueprints to size. The extra margin will also help protect the drawing when it is repeatedly handled or attached to the drawing board later for revisions.
The following discussion deals with the basic drafting format. By basic format, we mean the title block, revision block, list of materials, and other information that must be placed on applicable size drafting sheets.
The primary purpose of a drawing title block is to identify a drawing. Title blocks must be uniform in size and easy to read. You may mechanically letter or freehand letter a title block or use commercially available standard size drafting sheets with preprinted title blocks.
Generally, place the title block in the lower right-hand corner of the drawing sheet, regardless of the size of the drawing (except for vertical title block). You will use three sizes of title blocks: a block for A-, B-, C-, and G-size drawings (Figure 4-20), a slightly larger block for D-, E-, F-, H-, J-, and K-size drawings (Figure 4-21), and a vertical title block (Figure 4-22). The vertical title block format must be used for all 22-inch by 34- inch (D-size) drawings and is optional for 28-inch by 40-inch (F-size) drawings.
Figure 4-20 – Preparing title block for A-, B-, C-, and G-size drawings.
Figure 4-21 – Preparing title block for D-, E-, F-, H-, J-, and K-size drawings.
Figure 4-22 – Example of vertical title block.
In a multiple-sheet drawing, use either the basic title block or a “continuation sheet title block” format (Figure 4-23) for second and subsequent sheets provided all sheets are the same size. Certain information common to all drawings in the basic title block is optional in the continuation sheet title block.
Figure 4-20 shows the letter designations used to locate the following title block information.
(A) Record of preparation
(B) : This information will vary with each command or activity, but will normally include the dates and the surnames of the persons concerned with the preparation of the drawing. You may also place the applicable work request number or locally assigned drawing number in the upper portion of this space. This block is optional for continuation sheets. Drawing title: In the space provided for the drawing title, you will include the general project and the specific features shown on the drawing. Figure 4-23 – Use of continuation sheet title block and multiple sheet numbering. 4-21 Example 1: RESTROOM FACILITIES SEABEE PARK ARCHITECTURAL PLANS, ELEVATIONS, SECTIONS, DETAILS Example 2: DEFINITIVE DRAWING BERTHING PIER Once you enter the general project (such as RESTROOM FACILITIES, SEABEE PARK, in example 1) in the title block of sheet 1, do not repeat it on each sheet of a set of multiple-project drawings. Example 2 is the title taken from the title block of a drawing contained in NAVFAC P-272, Definitive Designs for Naval Shore Facilities. In this example the general project or common title, DEFINITIVE DRAWING, appears as the top line title on all drawings in NAVFAC P-272. This block is optional for continuation sheets. (C) Preparing activity The information you place in spaces (D) and (E) (Figure 4-21) varies with each command and with the purpose of the drawing (Figure 4-24). You will usually reserve one space for the signature of (APPROVED BY) your commanding officer or officer in charge and the other space for the signature of the commander of the activity or command requiring the drawing (SATISFACTORY TO). As Figure 4-24 shows in the examples, these two spaces may be used interchangeably. This is acceptable as long as you maintain consistency. It is also acceptable to use only space (E) when a SATISFACTORY TO space is not required for the drawing as shown on the NAVFAC title blocks in Figures 4-25 and 4-26. In this case, you will either extend the (F) space upward or the (A) space downward if you require additional space. If you do not require these blocks, you can combine them into block (A) for continuation sheets or use them for other purposes. : Reserve this space for the name and location of the activity preparing the drawing. In addition, place the words DEPARTMENT OF THE NAVY in this space. This block is optional for continuation sheets. 4-22 Figure 4-24 – Examples of title blocks used on drawings prepared by Naval Construction Battalion and Naval Construction Regiment. Figure 4-25 Example of a title block prepared by an activity not requiring NAVFACENGCOM 4-23 (F) Code identification number (G) : The federal supply code for manufacturers (FSCM) is a five-digit number used to identify the government design activity; that is, the activity having responsibility for the design of an item. For most of your drawings, NAVFAC has the ultimate design responsibility, therefore, you will use the identification number “80091” in the title block of all NAVFACENGCOM drawings. You may choose to use either “FSCM” or “Code 10” (the terms are interchangeable) in the title block. Drawing size (H) : Reserve this space for the letter designating the drawing format size. Drawing number (J) : If the drawing is prepared for or by NAVFACENGCOM, you will use a NAVFAC drawing number. MIL-HDBK 1006/1, Policy and Procedures for Project Drawing and Specification Preparation covers the assignment of NAVFAC drawing numbers. If the drawing does not require a NAVFAC drawing number, leave this space blank and use a local command drawing number in space (A). Occasionally, local title blocks require the drawing number to be in space (H). (Figure 4-24.) Scale (K) : Record the scale used to prepare the drawing in this space. When you use more than one scale in the drawing, use the words AS SHOWN or AS NOTED after the word SCALE in space (J). If the drawing is not to scale, enter the word NONE in this space. Specification number (L) : If you prepared the drawing for NAVFACENGCOM, use this space for the project specification or contract number. If the drawing does not pertain to a particular project specification or contract, you will normally leave this space blank. Sheet number 3.3.2 Satisfactory To Block : On a single construction drawing, you will enter SHEET 1 of 1 in this space. For numbering of second and subsequent sheets in a multiple-sheet drawing (Figure 4-23, View C), similar drawing numbers appear in both basic and continuation sheet title blocks; however, you will enter the total sheet number on sheet 1 and the specific sheet number on each subsequent sheet. In addition to spaces (D) and (E) on the title block, which are provided for approval signatures, you may require a second SATISFACTORY TO block when an outside activity requests a drawing. The extra SATISFACTORY TO block is identical to the SATISFACTORY TO space in the title block but is located adjacent to title block space (F). Figure 4-26 – Example of a title block used on drawing prepared by NAVFACENGCOM. 4-24 3.3.3 Revision Block A REVISION block contains a list of all revisions made to the drawing. On construction drawings, you will place the revision block in the upper right-hand corner. Basically, all revision blocks provide the same information; only the sizes of the blocks differ (Figure 4-27, Slide 1). Enter revision information chronologically starting at the top of the revision block. Use revision letters to identify a change or revision to a drawing. Use uppercase letters in alphabetical sequence, omitting the letters I, O, Q, S, X, and Z. Assign the letter A to the first revision to a drawing. Identify all changes that are incorporated in a drawing at one time by the same revision letter. You may number the changes sequentially to permit ready identification of a specific change. In this case, the appropriate serial number will appear as a suffix to the revision letter (for example, A1, A2, A3, etc.). Whenever possible, place the revision letter near the actual change on the drawing, positioning it so it will not be confused with other symbols on the drawing. Usually, you will place the revision letter inside of a circle or triangle. If you use a circle or triangle on the drawing, you should also use it in the revision block. Make a brief description of each change in the description column, adjacent to its revision letter, in the revision block. Also add the approval signature and date of revision in the appropriate columns. If you are preparing the drawing for Architect/Engineer (A/E) firms, your revision block should include a separate PREPARED BY column (Figure 4- 27, Slide 2). You will normally omit the zone column on the standard revision block on construction drawings but you may use it in reviewing maps. Indicate zones by alphabetical or numerical entries and space them evenly in the margin for locating an object on the drawing or map. DoD-STD-100C describes the use of zoning. Like title blocks, revision blocks may vary with each command, and you will be required to follow command guidelines. DoD-STD-100C covers the procedure for making revisions to drawings. 3.3.4 Bill of Materials When you use a BILL OF MATERIALS block on a construction drawing, place it directly above the title block against the right-hand margin. A bill of materials is a tabulated list of material requirements for a given project. The size of the BILL OF MATERIALS block will depend on the size of the drawing and the number of material items listed. On most Figure 4-27 – Format used in preparing revision blocks. 4-25 construction projects, it is impossible to list all items in a single BILL OF MATERIALS block; therefore, omit it from the drawings; an estimator will prepare a separate list of materials.
When you are preparing drawings, you will use different types of lines to convey information. Line characteristics, such as widths, breaks in the line, and zigzags, have definite meanings. Figure 4-28, taken from DoD-STD-100C, shows the different types of lines you should use on your drawings. The widths of the various lines on a drawing are very important in interpreting the drawing. DoD-STD-100C specifies that three widths of line should be used: thin, medium, and thick. As a general rule, on ink drawings, these three line widths are proportioned 1:2:4, respectively. However, the actual width of each type of line should be governed by the size and type of drawing. The width of lines in format features (that is, title blocks and revision blocks) should be a minimum of 0.015 inches (thin lines) and 0.030 inches (thick lines). To provide contrasting divisions between elements of the format, use thick lines for borderlines, outline of principal blocks, and main divisions of blocks. Use thin lines for minor divisions of title and revision blocks and bill of materials. Use medium line widths for letters and numbers. You cannot control the width of lines drawn with a pencil as well as the width of lines drawn with pen and ink. However, pencil lines should be opaque and of uniform width throughout their length. Cutting plane and viewing plane lines should be the thickest lines on the drawing. Lines used for outlines and other visible lines should be differentiated from hidden, extension, dimension, or center lines. Figure 4-28 – Use of line characteristics and conventions. 4-26
Usually the first lines that you will draw are construction lines. Use these same lines to lay out your drafting sheet; you will also use them to lay out the rest of your drawing. Line weight for construction lines is not important since they will not appear on your finished drawing. Construction lines should be heavy enough to see, but light enough to erase easily; use a 4H to 6H pencil with a sharp, conical point. With the exception of light lettering guidelines, you must erase or darken all construction lines before a drawing is reproduced.
Use center lines to indicate the center of a circle, arc, or any symmetrical object. (See Figure 4-29.) Compose center lines with long and short dashes, alternately and evenly spaced, with a long dash at each end. Extend center lines at least ¼ inch outside the object. At intersecting points, draw center lines as short dashes. You may draw a very short center line as a single dash if there is no possibility of confusing it with other lines. You can also use center lines to indicate the travel of a moving center, as shown in Figure 4-29.
Draw the visible edge lines of the view as solid, thick lines. The visible edge lines include not only the outlines of the view, but lines defining edges that are visible within the view. (See Figure 4-30.) Figure 4-29 – Use of center lines. Figure 4-30 – Use of visible edge lines. 4-27
Draw hidden edge lines with short dashes and use them to show hidden features of an object. Begin a hidden line with a dash in contact with the line from which it starts, except when it is the continuation of an unbroken line. (See Figure 4-31.) To prevent confusion in the interpretation of hidden edge lines, you must apply certain standard techniques in drawing these lines. A hidden edge line that is supposed to join a visible or another hidden line must actually contact the line, as shown in the upper views of Figure 4-32; the lower views show the incorrect procedure. Figure 4-31 – Use of hidden edge lines. Figure 4-32 – Correct and incorrect procedures for drawing adjoining hidden lines. 4-28 Figure 4-33 shows an intersection between a hidden edge line and a visible edge line. Obviously, on the object itself the hidden edge line must be below the visible edge line. Indicate this face by drawing the hidden edge line as shown in the upper view of Figure 4-33. If you drew it as indicated in the lower view, the hidden edge line would appear to be above, rather than beneath, the visible edge line. Figure 4-34 shows an intersection between two hidden edge lines, one of which is beneath the other on the object itself. Indicate this fact by drawing the lines as indicated in the upper view of Figure 4-34. If you drew them as indicated in the lower view, the wrong line would appear to be uppermost.
Use extension lines to extend dimensions beyond the outline of a view so that they can be read easily. Start these thin, unbroken lines about one sixteenth of an inch from the outline of the object and extend them about one-eight of an inch beyond the outermost dimension line. Draw extension lines parallel to each other and perpendicular to the distance you are showing. (Figure 4-35) In unusual cases, you may draw the extension lines at other angles as long as their meaning is clear. Figure 4-33 – Correct and incorrect procedures for drawing a hidden edge line that intersects a visible edge line. Figure 4-34 – Correct and incorrect procedures for drawing intersecting hidden edge lines that are on different levels. 4-29 As far as practical, avoid drawing extension lines directly to the outline of an object. When extension lines must cross each other, break them as shown in Figure 4-36.
Insert a dimension line, terminating at either end in a long, pointed arrowhead, between each pair of extension lines. You will draw a dimension line as a thin line with a break to provide a space for the dimension numerals (except in architectural and structural drafting). Occasionally, when you need to indicate the radius of an arc, you will draw an arrow only the end of the line that touches the arc. The other end, without an arrow, terminates at the point used as the center in drawing the arc. The arrowhead on a dimension or leader line is an important detail of a drawing. If you draw these arrowheads sloppily and varied in size, your drawing will not look finished and Figure 4-35 – Use of extension lines. Figure 4-36 – Breaking extension lines and leaders at points of intersection. 4-30 professional. The size of the arrowhead used on a drawing may vary with the size of the drawing, but all arrowheads on a single drawing should be the same size, except occasionally when space is very restricted. The arrowheads you will use on Navy drawings are usually solid, or filled in, and are between one eighth and one fourth of an inch long, with the length about three times the spread. (See Figure 4-37.) With a little practice, you can learn to make good arrowheads freehand. Referring to Figure 4-37, first define the length of the arrowhead with a short stroke as shown at A. Then draw the sides of the arrowhead as indicated at B and C. Finally, fill in the area enclosed by the lines, as shown at D.
Use leaders to connect numbers, references, or notes to the appropriate surfaces or lines on the drawing. From any suitable portion of the reference, note, or number, draw a short line parallel to the lettering. From this line, draw the remainder of the leader at an angle (dog leg) to an arrowhead or dot. In this way, the leader will not be confused with other lines of the drawing. If the reference is to a line, always terminate the leader at this line with an arrowhead, as shown in Figure 4-38. However, a reference to a surface terminates with a dot within the outline of that surface.
You may reduce the size of an object’s graphic representation (usually for the purpose of economizing on paper space) by using a device called a break. Suppose, for example, you wanted to make a drawing of a rectangle 1 ft wide by 100 ft long to the scale of 1/12, or 1 inch = 1 foot. If you drew the full length of the rectangle, you would need a sheet of paper 100 inches long. By using a break, you can reduce the length of the figure to a feasible length, as shown in Figure 4-39. Figure 4-37 – Method of drawing an arrowhead Figure 4-38 – Use of a leader. 4-31 On the original object, the ratio of width to length is 1:100. You can see that on the drawing, the ratio is much larger (roughly 1:8). However, the break tells you that a considerable amount of the central part of the figure is presumed to be removed. Use thick, wavy lines for a short break, as shown in Figure 4-39, View A. You will usually indicate a short break for rectangular sections with solid, freehand lines. For wooden rectangular sections, you will make the breaks sharper, with a serrated appearance, rather than wavy. For long breaks, you will use full, ruled lines with freehand zigzags, as shown in Figure 4-39, View B. For wider objects, a long break might have more than one pair of zigzag lines. For drawings made to a large scale, use special conventions that apply to drawing breaks in such things as metal rods, tubes, or bars. Figure 4-40 shows the methods of drawing these breaks. Figure 4-40 – Use of special breaks. Figure 4-39 – Use of proper line conventions for (A) short break, and (B) long break. 4-32
You will use phantom lines most frequently to indicate a moving part’s alternate position, as shown in the left-hand view of Figure 4-41. Draw the part in one position in full lines and in the alternate position in phantom lines. You will also use phantom lines to indicate a break when the nature of the object makes the use of the conventional type of break unfeasible. The right hand view of Figure 4-41 shows an example of this use of phantom lines.
Sometimes you can best convey the technical information in a drawing by a view that represents the object as it would look if part of it were cut away. A view of this kind is called a section. The upper view of Figure 4-42 shows a plan view of a pipe sleeve. The lower view is a section, showing the pipe sleeve as it would look, viewed from one side, if you cut it exactly in half vertically. The surface of the imaginary cut is crosshatched with lines called section lines. According to DoD-STD-100C, “section lining shall be composed of uniformly spaced lines at an angle of 45 degrees to the baseline of the section. On adjacent parts, the lines shall be drawn in opposite directions. On a third part, adjacent to two other parts, the section lining shall be drawn at an angle of 30 to 60 degrees.” You can use the cross-hatching shown in Figure 4- 42 on any drawing of parts made of only one material (like machine parts, for example, which are generally made of metal). The cross-hatching Figure 4-41 – Use of phantom lines. Figure 4-42 – Drawing of a plan view and a full section. 4-33 is the symbol for metals and may be used for a section drawing of any type of material. A section like the one shown in Figure 4-42, which goes all the way through and divides the object into halves, is called a full section. If the section showed the sleeve as it would look if cut vertically into unequal parts, or cut only part way through, it would be a partial section. If the cut followed one vertical line part of the way down and then was offset to a different line, it would be an offset section.
Use viewing plane lines to indicate the plane or planes from which a surface or several surfaces are viewed. Use cutting plane lines to indicate a plane or planes in which a sectional view is taken. Use section views to give a clearer view of interior or hidden features of an object that cannot be clearly observed in conventional outside views. Obtain a section view by cutting away part of an object to show the shape and construction at the cutting plane. Notice the CUTTING PLANE LINE AA in Figure 4-43, View A; it shows where the imaginary cut has been made. The single view in Figure 4-43, View B, helps you to visualize the cutting plane. The arrows point in the direction in which you are to look at the sectional view. Figure 4-43, View C is a front view showing how the object looks when cut it in half. The orthographic section view of Figure 4- 43, View D should be used on the drawing instead of the confusing front view in Figure 4-43, View A. Notice how much easier it is to read and understand. Note that hidden lines behind the plane of projection are omitted in the sectional view. These lines are omitted by general custom, because the elimination of hidden lines is the basic reason for making a sectional view. However, lines that would be visible behind the plane projection must be included in the section view. Cutting plane lines, together with arrows and letters, make up the cutting plane indications. Placing arrows at the end of the cutting plane lines indicates the direction to view the sections. The cutting plane may be a single continuous plane, or it may be offset if the detail can be shown to better advantage. On simple views, indicate the Figure 4-43 – Action of a cutting plane. 4-34 cutting plane as shown in Figure 4-43, View A. On large, complex views or when the cutting planes are offset, indicate them as shown as in Figure 4-44 Identify all cutting plane indications with reference letters placed at the arrowhead points. When a change in direction of the cutting plane is not clear, place reference letters at each change of direction. When more than one sectional view appears on a drawing, letter the cutting plane indications alphabetically. Include the letters that are part of the cutting plane indication as part of the title; for example, SECTION A-A, SECTION B-B, if the single alphabet is exhausted, multiples of letters may be used. You may abbreviate the word SECTION, if desired. Place the title directly under the section drawing.
Use a datum line to indicate a line or plane of reference, such as the plane from which an elevation is measured. Datum lines consist of one long dash and two short dashes equally spaced. Datum lines differ from phantom lines only in the way they are used.
Use stitch lines to indicate the stitching or sewing lines on an article. Stitch lines consist of a series of very short dashes (medium thickness), approximately half the length of the dash of hidden lines, evenly spaced. You can indicate long lines of stitching by a series of stitch lines connected by phantom lines.
Use match lines when an object is too large to fit on a single drawing sheet and must be continued on another sheet. Identify the points where the object stops on one sheet and continues on the next sheet with corresponding match lines. Match lines are medium weight lines labeled with the words MATCH LINE and referenced to the sheet that has the corresponding match line. Examples of construction drawings that may require match lines are maps and road plans where the length is much greater than the width and reducing the size of the drawing to fit a single sheet is impractical. Figure 4-44 – Use of an offset section.
With experience, you will find that a drawing can be made far more efficiently and rapidly if all the lines in a particular category are drawn at the same time and if the various categories of lines are drawn in a specific order or succession. Figure 4-45 shows the order in which the lines of the completed drawing (shown in the last view) were drawn. This order followed the recommended step-by-step procedures: 1. Draw all center lines. 2. Draw the principal circles, arcs, fillets, rounds, and other compass-drawn lines. A fillet is a small arc that indicates a rounded concave joint between two surfaces. A round is a small arc that indicates a rounded convex joint between two surfaces. 3. Draw the horizontal and vertical outlines, visible lines, and hidden lines. 4. Draw the non-horizontal and non-vertical outlines, visible lines, and hidden lines. 5. Clean up the drawing, erasing all excess lines and construction lines. A construction line is a light line used only as a drawing guide. 6. Draw extension lines, dimension lines, section lines, and any other lines required. 7. Inscribe the dimensions and lettering. To a limited extent you can vary the thickness of a pencil line by varying the extent to which you bear down on the pencil, but because you can’t bear down very hard without troughing the paper, you can’t get much variety in line weight with a pencil. If you will be inking over a drawing, this doesn’t make any difference. However, if you will not be reproducing a drawing or will be reproducing it directly from the pencil original, you must follow the line conventions as closely as possible. Figure 4-45 – Order of penciling a drawing.
As a novice, you may be intimidated by the prospect of inking a drawing without spoiling it. You can greatly reduce the danger of spoiling a drawing by learning how to use drawing instruments properly and following a definite order of inking. Nowadays, draftsmen prefer the reservoir pen or rapidograph to the ruling pen for inking straight and curved lines and even for lettering. On the other hand, you should NEVER use a ruling pen to ink freehand lines. One good way to avoid smeared ink lines is by using space blocks. These strips of tape or thin pieces of plastic, when fastened to both faces of the triangles, french curves, or templates (Figure 4-46), raise their edges from the surface of the drafting paper and prevent ink from running under the edge. When you use a rapidograph or reservoir pen with a T square or parallel straightedge, make long lines with a whole arm movement and short lines with a finger movement. Draw horizontal lines from left to right, starting at the top of the drawing and working down. (If you are left-handed, you will, of course, draw these lines from right to left, and similarly reverse many of the directions given in this training manual.) Vertical lines are usually drawn in an upward direction, moving from left to right across the drawing. However, when you have to draw a number of vertical lines or lines slanted in the same direction, the way you draw them will be governed by the source of your light and the way you have found that you can draw vertical lines with greatest control. Let the first lines dry before starting to draw any intersecting lines. Watch carefully when you draw one line across another line. You vary the thickness of ink lines by selecting a pen unit that matches your desired application and/or line convention. The order generally recommended for inking is as follows: 1. Start inking from the top of the paper and progress toward the bottom. 2.Start inking all arcs of circles, fillets, rounds, small circles, large circles, and other compass-drawn lines. 3. Ink all irregular curves, using a French curve or a spline as a guide. 4. Ink all thick horizontal lines, then all medium and thin lines. 5.Start at the left edge and ink the thick first, the medium next, and finally the thin vertical lines from left to right. 6. Follow the same procedure described in (4) and (5) for slanting lines. 7. Ink section lines, dimensions, and arrowheads. 8. Ink notes and title, meridian symbol, and graphic scales. 9. Ink borders and check inked drawing for completeness. Figure 4-46 – Use of space blocks. 4-37 10.Use an art gum or a kneaded eraser to erase pencil marks or for final cleanup of the drawing.
You cannot convey all of the information presented in a drawing by graphic shapes and lines alone. To make a drawing informative and complete, you must include lettering in the form of dimensions, notes, legends, and titles. Lettering can either enhance your drawing by making it simple to interpret and pleasant to look at, or it can ruin your drawing by making it difficult to read and unsightly in appearance. Mastering the techniques and skills required for neat, legible lettering is essential.
As you work with experienced draftsmen, you will notice their freehand lettering adds style and individuality to their work. They take great pride in their freehand lettering ability. By learning basic letter forms and practicing constantly, you will soon be able to do a creditable job of lettering and acquire your own style and individuality. Anyone who can write can learn to letter. As you practice, you will steadily improve both your style and the speed with which you can letter neatly. Don’t give up if your first attempts do not produce neat lettering. Don’t be afraid to ask your supervisor for a few pointers. You will gain an understanding of the letter shapes and the ability to visualize them by drawing them until the muscles of your hand are accustomed to the pattern of the strokes that make up the letters. You should be able to draw good letters without consciously thinking of this pattern. Your position and how you hold your pencil will greatly affect your lettering. You should sit up straight and rest your forearm on the drawing board or table. Hold the pencil between the thumb, forefinger, and second finger; the third and fourth fingers and the ball of the palm rest on the drawing sheet. Do not grip the pencil tightly. A tight grip will cramp the muscles in your fingers, causing you to lose control. If you get “writer’s cramp” easily, you are probably holding your pencil too tightly. The pencil should be kept sharpened to produce uniform line weights. A conical-shaped pencil point works best for most lettering. Usually, an F or H pencil is used for lettering. A pencil that is too hard may cut into the paper, or it may produce lettering that will not reproduce easily. A pencil that is too soft will require frequent sharpening, and it will produce lettering that may smear easily on a drawing.
Figure 4-47 shows the use of light pencil lines called guidelines. Guidelines ensure consistency in the size of the letter characters. If your lettering consists of capitals, draw only the cap line and base line. If lowercase letters are included as well, draw the waist line and drop line. 4-38 The waist line indicates the upper limit of the lowercase letters. The ascender is the part of the lowercase letter that extends above the body of the letter; for example, the dot portion of the character i in Figure 4-47. All ascenders are as high as the caps. The drop line indicates the lower limit of the lowercase letters. The descender is the part of the lowercase letter that extends below the body of the letter, an example being the tail of the character g in Figure 4-47. The vertical distance from the drop line to the base line is the same as the vertical distance from the waist line to the cap line. It is about one third of the vertical distance between the base line and the cap line, or about one half of the vertical distance between the base line and the waist line. Figure 4-48 shows an easy way to lay out guidelines for caps and lowercase. Let the height of a capital be 1 1/2 times the distance “a.” Set a compass or dividers to distance “a,” and lay off distance “a” above and below the midline selected for the guidelines. This method locates the cap line and the drop line. Then set the compass or dividers to one half of ’’a,” and lay off this distance above and below the midline. This method locates the waist line and the base line. To help you keep your lettering vertical, construct vertical guidelines, spaced at random along the horizontal guidelines. For inclined lettering, lay off lines inclined at the angle you wish your lettering to be slanted. (See Figure 4-49) Inclined lines are known as direction lines and are normally slanted at a maximum of 68 degrees. Figure 4-47 – Example of laying off guidelines use. Figure 4-48 – Laying off guidelines. 4-39 7.2.1 Ames Lettering Instrument If you have many lines of lettering to do, you will find a lettering instrument, such as the Ames lettering instrument, shown in Figure 4-50, quite useful and timesaving. The top-left section of Figure 4-50, shows how to use this instrument in conjunction with a T square to draw properly spaced horizontal guidelines. Insert the point of your pencil through one of the holes, and the instrument slides along the T square as you move the pencil across the page. The enlarged drawing of the instrument in the lower part of the figure shows the details of how the instrument is used. Notice the three rows of holes in the circular disc of the instrument. The holes in the center row are equally spaced guidelines. Use the two outside rows for drawing both capital and lowercase guidelines. Use the left row to get a proportion of 3 to 5 for lowercase and capital letters, and the right row for a proportion of 2 to 3. Figure 4-49 – Laying off lines for lettering. Figure 4-50 – Using the Ames lettering instrument. 4-40 You can use the Ames lettering instrument to create lettering ranging in height from 1/16 to 5/16 inches. You can attain different letter heights by rotating the circular disc within the outer section of the instrument. Use the numbers along the bottom edge of the disc to set the instrument for a particular letter height. A number aligned with the index line on the outer section of the instrument indicates the height of the lettering in 32nds of an inch. In Figure 4-50, the number 8 is aligned with the index; therefore, the distance between the capital letter guides produced by this setting is 8/32 inch or ¼ inch. By standing the Ames lettering instrument on its greater sloping side, you can use it for drawing guidelines for inclined lettering that slope at an angle of 67 1/2 degrees with the horizontal. (See the upper-right portion of Figure 4-50.) 7.2.2 Spacing between Guidelines The spacing between two lines of capitals may vary from one half of the height to the full height of a capital. Two thirds of the height is customarily used. The spacing commonly used between lines of lowercase letters is shown in Figure 4-51. The space indicated by the letter S equals the vertical distance between the waist line and the cap line. Figure 4-51 – Spacing between lines of lowercase letters. 4-41
The generally accepted style of lettering for SEABEE drawings is the single-stroke Gothic vertical (Figure 4-52) or inclined lettering. The term Gothic refers to the style of letters. Gothic lettering is the simplest style to make and the easiest to read on a drawing. Single-stroke means that each stroke of the letter is made by one stroke of the pencil. Figure 4-53 shows the basic strokes required for single-stroke lettering. Draw vertical strokes from the top down with an even finger movement. (You draw Inclined strokes in the same manner.) Draw horizontal strokes from left to right with a complete hand movement, pivoting at the wrist. Draw curved strokes proceeding from above downward, using a combined finger and wrist motion. Draw lettering strokes; do not sketch them. It is important to use the correct direction and sequence of strokes recommended for each letter. We will discuss and show the required shapes of vertical single-stroke Gothic letters and numerals in the next several figures and paragraphs. To emphasize the proportions of the letters and numerals, each character is shown in a grid, six units high. The grid serves as a reference for comparing the height of the various characters in proportion to their width as well as locating the individual strokes that compose the characters. For learning purposes, the characters are grouped by the type of strokes required to form each character. Figure 4-52 – Vertical single-stroke Gothic capitals and numerals. Figure 4-53 – Basic lettering strokes.
The capital letters shown in Figure 4-54 are formed with only straight-line strokes. Z, X, Y, K. Stroke 2 of the Z is longer than stroke 1. The inclined strokes of the X are closer together at their starting than at their finishing points. The three strokes of the Y intersect slightly below the center of the square. Stroke 2 of the K intersects stroke 1 at a point one third of the distance up from the base line. Stroke 3, if extended, would intersect stroke 1 at the top. See Figure 4-54. I, A, L, T. The letter I is the basic vertical stroke. Inclined strokes 1 and 2 of the A intersect just above the cap line; stroke 3 is located one third of the distance up from the base line. Draw the horizontal stroke of the T first; then draw the vertical stroke or stem from the center. With both L and T, the horizontal stroke may be lengthened or shortened to balance the letters in a word. If, for example, L precedes A, reduce its horizontal stroke slightly; if T precedes A, extend its horizontal stroke slightly. See Figure 4-55. E, H, F. In E, H, and F, the central horizontal bar is placed slightly above the center for stability. In both E and F, the cap line stroke is four units long and the central stroke is three fifths of this length. The base line of E is one-half unit longer than its cap line. See Figure 4-56. Figure 4-55 – Basic lettering strokes for I, A, L, and T. Figure 4-54 – Basic lettering strokes for Z, X, Y, and K. 4-43 M, N, W, V
The two inclined strokes of the V intersect just below the base line. The W is 1 1/3 times the width of a normal letter; note that it is wider than M. Strokes 1, 2, 3, and 4 of the W intersect below the base line. Strokes 3 and 4 of the M and 2 and 3 of the N intersect on the base line. Note that the outside strokes of the M and N are drawn first. See Figure 4-57. Figures 4-58 through 4-61 show capital letters formed by either curved line strokes or by a combination of curved- and straight-line strokes. O, Q, C, G. The O and Q are complete circles; C and G are not the full width of the square because they are not full circles. The tail of Q, if extended, would intersect the center of the circle. Stroke 4 of G begins at the center of the circle. See Figure 4-58. U, J, D. Stroke 3 of U is elliptical and connects two parallel vertical lines a third of the distance above the base line. Stroke 2 of J is similar but not so broad. Stroke 4 of D is circular, joining two horizontal segments. See Figure 4-59. P, R, B. The horizontal midstrokes of P and R lie just below the midpoint, and the horizontal midstroke of B lies just above the midpoint. Horizontal stroke 4 in B is slightly longer than strokes 2 and 3, which are the same length. See Figure 4-60. Figure 4-56 – Basic lettering strokes for E, F, and H. Figure 4-57 – Basic lettering strokes for M, N, W, and V. 4-44 S and &. The upper and lower portions of S are ellipses, the upper slightly smaller than the lower. The ampersand (&) is basically similar despite a greater difference in the sizes of the ellipses. See Figure 4-61. Figure 4-58 – Basic lettering strokes for O, Q, C, and G. Figure- 4-59 – Basic lettering strokes for U, J, and D. Figure 4-60 – Basic lettering strokes for P, R, and B.
It is vitally important for you to take extreme care in drawing numerals, particularly in the preparation of construction drawings. A poorly drawn numeral can cause costly errors and delays. Draw numerals using the same size guidelines as the capital letters on a drawing. Place vertical guidelines at random. Do not make numerals too small or crowded, since this can impair their legibility. Figure 4-62 shows that the vertical stroke of the numeral 4 is placed two units from the right side. The horizontal bar is one quarter the height of the number above the base line. Note that the closed curves of 0, 6, and 9 are elliptical, not circular. The 6 is an inverted 9. The 8 is composed of two ellipses tangent slightly above the center point. The top ellipse also is narrower. The 3 is the same as the 8 with the left portions of the loops cut off. The curved lines of 2 follow the elliptical contours of 8. The top portion of the 5 is slightly narrower than the bottom. The bottom ellipse is two thirds of the height of the figure from the base line. Figure 4-61 – Basic lettering strokes for S and &. Figure 4-62 – Lettering vertical numerals. 4-46 Always draw the division bar between the numerator and denominator of the fractions as parallel to the guidelines, as shown in Figure 4-63. The complete height of a fraction is twice that of a whole number. Center the division bar midway between the base line and cap line. Space the top guideline of the numerator and the bottom guideline of the denominator a full number height from the division bar. The numbers composing a fraction are three quarters of the height of a full number. The clear space on either side of the division bar is one quarter of a full number. Center the numbers in a fraction about a vertical guideline that cuts the fraction bar in half.
Never use lowercase letters on construction drawings, although it is acceptable to use them for notes on maps or similar drawings. NEVER use lowercase letters on drawing title blocks. Figure 4-64 shows lowercase letters along with guidelines and strokes used to form each letter. The crosses of f and t are on the waist line and extend the same distance on either side of stroke 1. The horizontal stroke of e is just above mid height. The bodies of a, b, g, p, and q are circular and vertical strokes of these letters do not increase their width at the points of tangency. The vertical strokes of p and q terminate at the drop line. The vertical strokes of g, j, and y terminate in curves that are tangent to the drop line. Figure 4-63 – Vertical fractions.
Inclined single-stroke Gothic lettering is also acceptable on SEABEE drawings, although it is not recommended for the beginner and should not be attempted until you have mastered vertical lettering techniques. Inclined and vertical lettering should never appear on the same drawing. The lettering style used must always be consistent. Figures 4-65 and 4-66 show the required formation of inclined letters. The angle of inclination is 67 1/2 degrees from the horizontal. Inclined guidelines may be drawn with the lettering triangle as described, or a line at the proper angle may be laid off with the protractor and parallel lines constructed from it. Horizontal guidelines and sequence of strokes are the same as for vertical letters. Rules of stability, proportion, and balance are similar. The circles and circular arcs used in vertical letters become elliptical in inclined letters, their major axes making angles of 45 degrees with the horizontal. Letters such as A, M, V, and Y should be made symmetrically about a guideline. Inclined lowercase letters follow the same principles as inclined capitals. Figure 4-64 – Lettering vertical lowercase letters. 4-48
Once you have learned the proper shapes and strokes required to form each letter and numeral, concentrate on practicing the composition of words and sentences. Proper spacing of letters and words does more for the appearance of a block of lettering than the forms of the letters themselves. This does not mean, however, that you should discontinue further practice of correctly forming each letter.
In straight-line lettering, determine the spacing between letters by eye after making the first letter and before making each succeeding letter. To give a word the appearance of having uniformly spaced letters, make the areas between the letters nearly equal, as shown in Figure 4-67. The areas between adjacent letters in a word vary with respect to whether the letters have straight sides (H, I, M, N) or slanted sides (A, V, W) and whether the letters are round (O, Q, C, G) or open (L, J). You will draw adjacent straight-sided letters farther apart than adjacent round letters. You will draw adjacent slant-sided and open letters nearer together than adjacent round letters. Where letters L and T, L and V, A and V, and other pairs of like shape come together in a word, you may have to draw the top of one above the bottom of the other to avoid having the word Figure 4-66 – Inclined letter formation. Figure 4-65 – Inclined single-stroke Gothic. 4-49 appear as two or more words. In letter spacing, the six problems listed below are the hardest to solve. You will solve the first five problems by moving the letters closer together, the sixth by moving the letters farther apart. 1. Round next to round. (Increase the area at top and bottom where letters curve away from each other, as in Figure 4-68A.) 2. Round next to slant. (Increase the area at top or bottom where letters move away from each other, as in Figure 4-68B.) 3. Vertical next to slant. (Increase the area at top or bottom where one letter slants away from the other, as in Figure 4-68C.) 4. Slant next to slant. (Increase the area at top or bottom where letters slant in opposite directions, as in Figure 4-68D.) 5. Round next to vertical. (Increase the area at top and bottom where round letter curves away, as in Figure 4-68E.) 6. Vertical next to vertical. (Decrease the area at top and bottom where stems move together, as in Figure 4-68F.) Figure 4-67 – Letter spacing. Figure 4-68 – Common spacing problems. 4-50 A good way to evaluate the spacing of letters is to hold the lettering away from you and squint your eyes, observing the gray tone throughout the lettering. If the tone appears spotty or varies too much, the letters are poorly spaced.
Proper spacing between words is an important factor in making them easy to read. Allow enough space between words and sentences to keep them from running together, but not so much as to cause words to be read one at a time. A good practice to follow is making spaces between words equal to the space that the letter O occupies as shown in Figure 4-69. If you prefer, you can use the letter N or a correctly spaced letter I instead. Naturally, the design of the last letter of a word and of the first letter of the following word must be considered in determining the amount of space you leave between words. You should leave a space equal to a capital O between two full-height straight-stemmed letters, such as H and E or D and B. Of course, if one or both of the letters are curved, the space should be appropriately reduced. If the two letters involved are lowercase, use the lowercase o to determine the width of the space. If one letter is full height and the other is lowercase height, such as the words bid now or on him, the space is equal to half a capital O and half a lowercase o.
In addition to the spacing between letters and words, the spacing between lines of lettering adds to the readability of the lettering. Again your eye and your artistic ability must be your guide. Except when you are trying for a special effect, you should have enough space between the lines to make it easy for the reader to see what he is reading. The distance you leave between lines may vary from 1/2 to 1 1/2 times the height of the letter. For the sake of appearance, do not use the same distance as the letter height. As a general rule, two-thirds of the letter height is a good distance between lines. This spacing allows room for descenders of lowercase letters and still maintains a clear space of one third of the letter height between the descenders and capital letters, or ascenders of lowercase letters of the following line. Figure 4-69 shows proper word and line spacing. Figure 4-69 – Spacing between words and lines.
Since the letters of the alphabet vary in width, you may find it difficult to center a line of lettering. Figure 4-70 shows one way of solving this problem. First, take a piece of scratch paper and letter in the required line. Then, place this lettering above the area in which your lettering is to go and center it. Finally, use the sample as a guide to lettering the desired line. Ending a line of lettering at a given point is equally difficult. As in centering, first, letter the line on a piece of scratch paper in order to achieve the proper line length. To make lines of lettering come out to a specified length, you must adjust the word and/or letter spacing. This adjustment in spacing is called justifying. A good example of justifying is found in the columns of this manual. Notice how all full lines start and stop on the right- and left-hand margins. Usually, you will only find justified lettering typeset or typewritten by mechanical means. However, if you do have an occasion to justify your lettering, you should try to keep the spacing between the words as uniform as possible. Uneven spacing detracts from the appearance of the job. When it is impossible to divide the spacing evenly, insert wider spacing at points where one word ends and the next begins with tall letters, like d, b, and l. If you use too much space between the words, the paragraph will tend to fall apart because it is filled with rivers of white space that will disturb the eye. When a line is so short that it calls for an undue amount of space between words to lengthen the line, allow more space between the letters in each word. This is known as letterspacing. When words are letterspaced, always allow extra space between words so that they will not seem to run together when they are read. Letter spacing makes short words in titles or headings appear longer. Though it frequently improves the appearance of words in caps, letter spacing reduces the legibility of words in lowercase. Use this process with caution. Figure 4-70 – Centering with trial spacing paper. 4-52
At times you will be tasked with preparing drawings, charts, maps, or signs that require the use of mechanical lettering. When we refer to mechanical lettering, we mean standard uniform characters that are executed with a special pen held in a scriber and guided by a template. Mechanical lettering does not normally require the use of lettering guidelines. You will use mechanical lettering principally for title blocks and notes on drawings, marginal data for special maps, briefing charts, display charts, graphs, titles on photographs, signs, and any other time that clear, legible, standardized lettering is required. Note that freehand lettering is the required lettering on most of your drawings; reserve mechanical lettering for special uses similar to those described above. The availability of mechanical lettering devices should not deter you from the daily practice required to execute freehand lettering. With continuous practice, you will become proficient in both mechanical and freehand lettering. One of the most popular types of mechanical lettering sets is the LEROY lettering set. A standard Leroy lettering set consists of a set of templates, a scriber, and a set of pens. (See Figure 4-71.)
10.1.0 Templates
Templates are made of laminated plastic with the characters engraved in the face so that the lines serve as guide grooves for the scriber. The height of the characters, in thousandths of an inch, is given by a number on the upper right-hand side of the template. For example, 3240-500CL indicates a No. 500 template. The entire number and letter designation identifies the template in the manufacturer’s catalog. A standard set of templates offers character heights from 80 (0.08 inch or 5/64 inch) to 500 (0.5 inch or 1/2 inch). The scale at the bottom of each template has the zero in the center and is arranged for proper spacing in relation to character heights. The distance between each scale division represents the center-to-center distance of normal-width letters.
10.2.0 Pens
A standard set of pens for producing various line weights consists of 11 sizes ranging from 000, the finest, to 8. Each pen is composed of two parts: the ink reservoir and the cleaning pin. The reservoir is a series of connected tubes of decreasing diameters, the smallest establishing line thickness. The cleaning pin acts as a valve, protruding beyond the edge of the bottom tube when the pen is not touching the drawing surface. In this position, no ink flows. When the pen is resting on a drawing surface, the cleaning pin is pushed up, allowing the ink to flow. The action of the pin in the tube minimizes ink clogging. Figure 4-71 – Leroy lettering set. 4-53 NOTE As stated earlier, some reservoir pens are made so the point section will fit in a Leroy scriber. They are popular with the SEABEEs (and widely used over the standard pens contained in the Leroy, especially for long hours of lettering. A SCRIBER holds the pen in alignment and controls its motion as the tracing pin is guided through the character grooves of the template. Two types of scribes are available: adjustable and fixed. An adjustable scriber produces letters with any slant from vertical to 22 1/2 degrees forward from a single template; a fixed scriber produces only vertical letters. Both scribers consist of a tracing pin, pen socket, socket screw, and tail pin. Figure 4-72 shows a fixed scriber. The tracing pin on most Leroy scribers is reversible. One point is used with fine groove templates (Nos. 060, 080, and 100), and the other point is for wider groove templates (No. 120 to No. 500). 10.3.0 Line Weights The table below shows the recommended combinations of template and pen for the best proportion between line thickness and letter size. Figure 4-72 – Leroy scriber and template. 4-54 Template No. Pen No. 060 000 080 000 or 00 100 00 120 0 140 1 175 2 200 3 240 3 290 4 350 4 425 5 500 6 This list is also found inside the lid of the Leroy lettering set case. 10.4.0 Operating Procedures You will require a certain technique to manipulate the Leroy scriber with the template and, at the same time, hold the template against the working edge of the T square or straightedge without slipping. Hold the T square or straightedge in position with the ball of your left hand resting on the blade while using the fingers of your left hand to hold the template against the working edge and changing the position of the template when necessary. Hold the scriber between your thumb and first three fingers of your right hand. The little finger of the right hand presses the right side of the template against the working edge, preventing the tracing pin from slipping out of the character grooves of the template. Take care to keep the tail pin in the straight-guide groove at the bottom of each template. When you are making long lines of large lettering, you may find it helpful to secure the T square or straightedge at both ends of the drawing board with drafting tape. Using the above techniques to manipulate the scriber and template, follow the steps listed below to form uniform letters, words, and sentences. As you follow the steps, refer to Figure 4-72. 1.Select the template with letters of the desired height. The distance between each graduation at the bottom of the template is equal to the height of the letter that can be made with the template. The numbers in a fraction are made by using a template one size smaller than that used for whole numbers. 2. Lay the template along the top edge of a T square or straightedge. 4-55 3. Using the table of recommended template and pen sizes previously mentioned, select the proper pen to give a well-proportioned letter. NOTE On drawings with a great deal of lettering, the recommended combinations may be altered by one pen size, either under or over the recommended size, for variation and appearance. Never use a pen size more than two over the recommended size. 4. Insert the selected pen into the socket of the scriber arm until the shoulder of the pen rests on the scriber arm. 5. Tighten the screw on the side of the scriber arm. 6. Loosen the locknut on the adjusting screw in the scriber arm. 7. Set the tail pin of the scriber in the straight-guide groove of the template. 8. Set the tracer pin of the scriber in the groove of a character. 9. Lower the pen gently to the drawing surface. 10.Raise or lower the scriber arm by turning the adjusting screw until the tip of the cleaning pin within the pen just touches the drawing surface. Tighten the locknut when the desired height is reached. To prevent blotting, make this rough adjustment before putting ink into the pen. 11. Remove the scriber from the template. 12.Remove the cleaning pin from the pen. NOTE To prevent the ink from flowing straight through the pen, you should not remove the cleaning pin of a Leroy pen No. 4 or larger from the pen. 13.Fill the reservoir of the pen with drawing ink. You should fill the Leroy pen with ink in the same manner as any common drafting inking instrument. Keep the reservoir from one-fourth to three-fourths full; too low an ink level results in irregular lines. 14.If you removed the cleaning pin, reinsert it into the pen. 15.Wipe the lower tip of the pen with a cloth to remove any excess ink that may have been pushed through by the cleaning pin. 16.Draw a test line on a piece of scratch paper to ensure that the ink will flow smoothly. 17.Gently lower the pen to the drawing surface after inserting the tail and tracer pins in their proper grooves. 18.Proceed with the lettering by moving the tracer pin in the grooves of the characters, keeping the tail pin in the straight-guide groove. If the ink does not flow properly, turn the cleaning pin inside the pen and wipe the tip with a cloth; also, make any necessary minor adjustments to the adjusting screw to allow the ink to flow properly. Tighten the locknut. When you will not be lettering for short periods of time, place the tip of the pen, still in the socket of the scriber arm, on a piece of moist cotton. This will prevent the ink from drying around the opening of the pen and will help the ink to flow properly when you begin lettering again. 4-56 10.5.0 Spacing and Centering The rules for freehand letterspacing and word spacing also apply to mechanical lettering. Guidelines are not necessary for mechanical lettering; however, when you are making more than one line of lettering, you may draw horizontal base lines at intervals to help you maintain the proper spacing between the lines. Spacing between lines of mechanical lettering is the same as for freehand lettering. When centering lettering above a certain part of a drawing, or within a certain space, use the scales along the bottom edges of the templates. Each space on the scale represents the center-to-center distance of normal-width letters. For example, to center the words LEROY LETTERING about a certain line, proceed as follows: 1. Count the letters in each word and the spaces between words. Result: 15. 2. Considering the letter I and the space between the words as half value for each, reduce the total by one. Result: 14. 3. Divide the result of No. 2 above by two. Result: 7. NOTE If there had been an odd number of half values, you would use the next lower number and allow more space between words than normally required. 4.Set the zero of the scale at the vertical line about which the lettering is to be centered and mark off seven spaces to the left and right of zero. 5.Start the L of the word LEROY in the title at the left mark and continue to the end. The right edge of the G should fall on the mark to the right. 10.6.0 Maintenance of Mechanical Lettering Equipment Thoroughly clean your pens with water after each use and store them properly in the lettering set case. Never wash your pens under running water in a sink; you may accidently lose the pens and cleaning pins down the drain. If you cannot clean a pen satisfactorily with water, use a diluted solution of ammonia or available commercial pen cleaning solutions and pen cleaning kits. You can remove caked or dried ink by soaking the pens overnight in a cleaning solution. Be aware, however, the pens may corrode if soaked excessively. Handle cleaning pins with care because they are fragile and easily bent, especially the smaller ones. Avoid excessively tightening the screw that holds the pen in the scriber because the fine threads tend to strip very easily. Clean your templates after every use, because dirt and dried-on ink are very easily transferred onto an otherwise clean drawing. Ensure that the template grooves are kept free from all foreign matter and that the tracer pin does not cut into the sides of the grooves. In order to form perfect letters every time, you must make sure that the tracer pin slides along the grooves smoothly. When you use small templates, insert a small sharp tracing pin in the scriber. If you are using a larger template, avoid using a sharp tracing pin because it can damage the grooves of the template.
As an engineering technician, you will use a variety of drafting equipment and accessories in performing your day to day duties. Familiarity with fundamental techniques and standards will help you perform your tasks successfully.
1. The best light for drafting is natural light coming over the left shoulder and from the front left to avoid shadows cast by your hands. A. True B. False 2. To obtain a smooth drawing surface, cover your drafting board with __________. A. Vinyl or heavy manila paper B. Tracing paper or gridded paper C. Cloth D. Nothing 3. To clean up smudges on a tracing paper drawing, use an electric eraser. A. True B. False 4. Use a __________ pencil to lay out the drawing in light construction and projection lines and a __________ pencil to darken the required lines and to make arrowheads and lettering. A. Soft, hard B. Hard, soft C. Medium, soft D. Hard, medium 5. You can correct a poor pencil drawing when you trace it in ink. A. True B. False 6. When using a T square with a drawing board, align your paper to the __________ of the board. A. Top B. Bottom C. Left D. Right 7. You should draw horizontal lines from right to left. A. True B. False 4-59 8. You should draw vertical lines from the bottom up. A. True B. False 9. How is the direction or angle of inclination of an incline line measured? A. In reference to the left side of the drawing board B. In reference to the right side of the drawing board C. In reference to the base line from which it is drawn D. In reference to the triangle used 10. Using three points on the protractor to draw an angle will result in extremely accurate measurements. A. True B. False 11. Parallel and perpendicular lines are drawn with a combination of straightedges and triangles. A. True B. False 12. Noncircular curves are usually drawn __________. A. With protractors B. With curves C. With compasses D. Freehand 13. Always rotate the compass __________. A. Counterclockwise B. Clockwise and then counterclockwise C. Counterclockwise and then clockwise D. Clockwise 14. When you are drawing a curved line that extends into a straight line, draw the straight line first, and join the curve line to it. A. True B. False 15. Use drafting templates __________. A. Whenever you're in a hurry B. When speed can be sacrificed for accuracy C. When accuracy can be sacrificed for speed D. When you can't find a compass 4-60 16. __________ are used to transfer measurements, to step off a series of equal distances, and to divide lines into a number of equal parts. A. Protractors B. Scales C. Dividers D. Straightedges 17. Scales are suitable for drawing lines. A. True B. False 18. __________ refers to the systematic space arrangement of required information within the drafting sheet used to identify, process, and file drawings methodically. A. Drawing format B. Sheet size C. Roll size D. Title block 19. The __________ is the outside line of either the vertical or horizontal margin. A. Borderline B. Trim line C. Hidden line D. Extension line 20. The inside lines of the margins are called _________. A. Borderlines B. Trim lines C. Hidden lines D. Extension lines 21. Sheets of drafting or tracing paper are cut __________ their required finished size and fastened to the drafting board. A. Exactly to B. Slightly smaller than C. Slightly larger than D. Double the size of 22. The title block, revision block, and list of materials are part of the __________. A. Drawing number B. Record of preparation C. Sheet size D. Basic format 4-61 23. The primary purpose of the __________ is to identify a drawing. A. Bill of Materials B. Satisfactory To C. Revision block D. Title block 24. The __________ is an additional approval signature block provided when an outside activity requests a drawing. A. Bill of Materials B. Satisfactory To C. Revision block D. Title block 25. The ___________ contains a list of all changes made to the drawing. A. Bill of Materials B. Satisfactory To C. Revision block D. Title block 26. The __________ is a tabulated list of material requirements for a given project. A. Bill of Materials B. Satisfactory To C. Revision block D. Title block 27. DoD-STD-100C specifies that __________ widths of line should be used in drafting drawings. A. 2 B. 3 C. 4 D. 5 28. The first lines you will draw are __________, and they are used to lay out the rest of your drawing. A. Hidden lines B. Visible lines C. Center lines D. Construction lines 4-62 29. Use __________ to indicate the center line of a circle, arc, or any symmetrical object. A. A solid, thick line B. A thin unbroken line C. Long and short dashes, alternately and evenly spaced, with a long dash at each end D. Short dashes 30. Visible lines are drawn as __________. A. A solid, thick line B. A thin unbroken line C. Long and short dashes, alternately and evenly spaced, with a long dash at each end D. Short dashes 31. Hidden edge lines are drawn with __________. A. A solid, thick line B. A thin unbroken line C. Long and short dashes, alternately and evenly spaced, with a long dash at each end D. Short dashes 32. Extension lines are drawn with ___________. A. A solid, thick line B. A thin unbroken line C. Long and short dashes, alternately and evenly spaced, with a long dash at each end D. Short dashes 33. __________ lines are terminated at each end with arrows and inserted between each pair of extension lines. A. Center B. Visible C. Hidden edge D. Dimension 34. __________ are used to connect numbers, references, or notes to the appropriate surfaces or lines on the drawing. A. Phantom lines B. Dimension lines C. Leaders D. Break lines 4-63 35. This device is used to reduce the size of an object's graphic representation (usually for the purpose of economizing on paper space). A. Phantom lines B. Dimension lines C. Leaders D. Break lines 36. ___________ are used frequently to indicate a moving part's alternate position. A. Phantom lines B. Dimension lines C. Leaders D. Break lines 37. Cutaway views are called __________. A. Leaders B. Sections C. Dimensions D. Crosshatching 38. __________ lines indicate the plane or planes from which a surface or several surfaces are viewed. A. Cutting plane B. Viewing plane C. Dimension D. Crosshatching 39. A __________ line consists of one long dash and two short dashes equally spaced. A. Phantom B. Dimension C. Datum D. Break 40. Stitch lines consist of __________. A. A series of very short dashes of medium thickness, approximately have the length of the dash of hidden lines, evenly spaced B. A solid, thick line C. A thin unbroken line D. Long and short dashes, alternately and evenly spaced, with a long dash at each end 4-64 41. __________ lines are used when an object is too large to fit on a single drawing sheet and must be continued on another sheet. A. Break B. Dimension C. Datum D. Match 42. When penciling a drawing, __________ lines should be drawn first. A. Horizontal and vertical outlines B. Circles and arcs C. Center D. Nonhorizontal and nonvertical outlines 43. __________ are strips of tape or thin pieces of plastic which are fastened to faces of triangles, curves and templates to raise their edges from the surface of the drafting paper and prevent ink from running under the edge. A. Space blocks B. Drafting tape C. Masking tape D. Duct tape 44. When freehand lettering, you should grip the pencil tightly. A. True B. False 45. __________ ensure consistency in the size of the letter characters. A. Trim lines B. Guidelines C. Phantom lines D. Center lines 46. The generally accepted style of lettering for Seabee drawings in the __________. A. Arial Bold B. Single-stroke Gothic vertical or inclined C. Times Roman D. Comic Sans 47. Z, X, Y, K are formed with only __________. A. Horizontal strokes B. Curved and straight-line combinations C. Curved strokes D. Straight-line strokes 4-65 48. O, Q, C, G are formed with only __________. A. Horizontal strokes B. Curved and straight-line combinations C. Curved strokes D. Straight-line strokes 49. Drawing numerals requires a different set of guidelines than capital letters. A. True B. False 50. It is acceptable to use lowercase letters on construction drawings. A. True B. False 51. Inclined lettering uses the same horizontal guidelines and sequence of strokes as vertical lettering. A. True B. False 52. The spacing between adjacent letters in a word is always the same. A. True B. False 53. A good practice is to make the spaces between words equal to the space that the letter __________ occupies. A. l B. j C. O D. i 54. The recommended distance you leave between lines is __________ the height of the letter. A. Triple B. Double C. Equal D. Varies from 1/2 to 1 1/2 times 4-66 55. __________ is adjusting word and/or letter spacing to make lines of lettering come out to a specified length. A. Composition B. Centering C. Justifying D. Formation 56. __________ refers to standard uniform characters that are executed with a special pen held in a scriber and guided by a template. A. Freehand lettering B. Mechanical lettering C. Drafting templates D. Cursive lettering 57. __________ are made of laminated plastic with the characters engraved in the face so that the lines serve as guide grooves for a scriber. A. Templates B. Protractors C. Compasses D. Straightedges 58. A standard set of pens for producing various line weights consists of 11 sizes ranging from 000, the __________, to 8. A. Finest B. Widest C. Thickest D. Darkest 59. When using a Leroy scriber to draw long lines of large lettering, you may find it helpful to secure the T square or straightedge at both ends of the drawing board with drafting tape. A. True B. False 60. Spacing between lines of mechanical lettering is different than freehand lettering. A. True B. False 61. You should wash your pens under running water in a sink. A. True B. False