redrawn more quickly than mistakes can beerased.For making dimensioned sketches in the field,you will need some sort of measuring tape—eithera pocket rule or a surveyor’s tape, depending onthe extent of the measurements taken. If you arerequired to collect extensive field data, it wouldbe to your benefit to maintain a sketch notebook.A surveyor’s field notebook works well for thispurpose.TECHNIQUES OF SKETCHINGThe sketch should conform to one of the stan-dard types of projection discussed in this chapter.You must apply correct proportion wheneverpossible. When you use cross-section paper, itsgrid will provide a ready scale that will aid you insketching proportionally. You do this by countingthe squares within the object to be drawn. The sizeof your sketch depends upon the complexity ofthe object and the size of paper you are using.Sketching Straight LinesIn sketching lines, place a dot where you wanta line to begin and one where you want it to end.In sketching long lines, place one or more dotsbetween the end dots. Then swing your hand inthe direction your line should go, and back againa couple of times before you touch your pencilto the paper. In this way you get the feel of theline. Then use these dots to guide your eye andyour hand as you draw the line. Draw each linewith a series of short strokes instead of with onestroke. Using short strokes, you can bettercontrol the direction of your line and the pressureFigure 5-58.-Use of paper, pad, or table as a guide whendrawing straight lines.of your pencil on the paper. Hold the pencil aboutthree quarters of an inch to an inch from the pointso that you can see what you are doing. Strive fora free and easy movement rather than a crampedfinger and wrist movement.Another useful technique in drawing straightlines is to use the side of the paper, pad, or tableas a guide for your hand. Hold the pencil at thedesired starting point of the line and place the heelof your hand and one finger on the guide, asshown in figure 5-58. Move the pencil, in this case,with one uniform stroke to complete the line. Trydrawing several light horizontal lines and, aftereach one is drawn, examine it for straightness,weight, and neatness. If it is too light, use eithera softer pencil or a little more pressure.Vertical lines are usually sketched downwardon the paper. The same suggestions for usinglocator dots, free movement of the entire arm,and guides apply to vertical lines as they do tohorizontal lines.Slanting lines may be drawn from either endtoward the other. For better control, you mightfind it helpful to rotate the paper, thus placingthe desired slanting line in either the horizontalor vertical position.To keep your sketch neat, first sketch yourlines lightly. Lines not essential to the drawing canbe sketched so lightly that you need not erasethem. Darken essential lines by running yourpencil over them with more pressure. Figure 5-59shows line conventions drawn with various typesof pencil points.Figure 5-59.-Line conventions drawn with various types ofpencil points.5-30
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business