Technical drawing exercises are activities that beginning drafters perform to learn how to produce clear drawings, which are essential to the timely and accurate manufacturing of a product. The specific benefit that comes from doing technical drawing exercises is the ability to consistently create drawings that convey the impression of actual objects that exist in space.
Drawing Multiple Views
Technical drawing students practice observing an existing object and then drawing its top, bottom, right and left views. This is done so that a student can learn how to fully define and visually explain an object to the crew who'll make the object. In drawing the various views, the student follows several conventions that make her drawing clear for that crew. One convention is aligning the left and right extremes of an object's top view with the same extremes in the front view. By doing this, whoever reads the drawing will see how the top and front views relate to each other, to form a representation of the physical object.
Drawing Ellipses without Templates
Technical drawing students also practice drawing accurate ellipses without the aid of ellipse templates. This exercise is important because ellipses occur in so many drawings. One reason for this prevalence is that circles are found in many designs, and technical drawings typically need to display views that foreshorten the circles. A foreshortened circle is an ellipse. (Foreshortening is what makes a pencil, for example, appear shorter than its full length when you hold it an any angle that's not perpendicular to your line of sight.)
Students practicing ellipse drawing can use several methods for producing smooth renderings of this common shape. One is to construct a rectangle that will surround the ellipse. Students divide the rectangle into four smaller rectangles of equal size, then make evenly spaced hash marks along the top left rectangle's left and bottom sides. Drawing rays through these marks and the top and bottom midpoints of the original rectangle produces points that lie on an ellipse.
Drawing Axonometric Views
Drawing axonometric views is an exercise that shows technical drawing students how to present a basic three dimensional (3-D) view, called an axonometric view, of an object from 2-D views of the object. The student will construct the view by drawing the appearance of a 3-D box, whose faces have the same dimensions (distorted somewhat by foreshortening) as the top, left or right and front 2-D faces. The student transfers points on the axonometric box's sides from those 2-D views, then draws rays through those points until they intersect in the box's interior. The intersection point represents the 3-D view of a single point of the final object.
- "Drafting for Industry," Walter Brown and Clois Kicklighter; 1995
- house plan image by Jon Le-Bon from Fotolia.com