TABLE OF CONTENTS To introduce methods of constructing drawings of two types orthographic projection and isometric drawings.
Orthographic projection involves viewing an article being described in a technical drawing from different directions from the front, from a side, from above, from below or from any other viewing position. Orthographic projection often involves:
The drawing of details which are hidden, using hidden detail lines;
Sectional views in which the article being drawn is imagined as being cut through and the cut surface drawn;
Centre lines through arcs, circles, spheres and cylindrical shapes.
Taking the solid shown in Fig. 7.1, construct a three-view orthographic projection of the solid:
Draw what is seen when the solid is viewed from its left-hand side and regard this as the front of the solid. What is drawn will be a front view (Fig. 7.2).
Fig. 7.2: The front view of the solid
Draw what is seen when the solid is viewed from the left-hand end of the front view. This produces an end view. Fig. 7.3 shows the end view alongside the front view.
Fig. 7.3: Front and end views of the solid
Draw what is seen when the solid is viewed from above the front view. This produces a plan. Fig. 7.4 shows the plan below the front view.
Fig. 7.4: Front and
