74 Print Reading for Industry Copyright Goodheart-Willcox Co., Inc. The purpose of a drawing is to show the size and shape of the object. A drawing can also pro- vide certain information about how an object is to be made. Various methods of presentation are available to the designer or drafter. However, the best way to show every feature of an object is to use a multiview drawing, a systematic arrangement of more than one view of an object’s features. Multi- view drawings are created using the principles of orthographic projection. Many drafting and print reading texts use the terms orthographic projection and multiview drawing interchangeably. The stan- dard practices for multiview drawings are covered in ASME Y14.3, Orthographic and Pictorial Views. This unit forms the foundation for many other units. This unit explains how views are projected and addresses the abstract ability to visualize geo- metric shapes and figures. The Role of Spatial Skills A skilled technician reading a print must be able to visualize the part as a whole. The print reader must be able to look at the views in a drawing and interpret those into a mental picture, Figure 5-1. By definition, spatial visualization can be defined as the mental visualization of 2D and 3D shapes and objects, including such tasks as imagining objects in the mind as they are rotated, moved, or reflected in a mirror. While it is beyond the scope of this text to cover spatial skills in depth, there is a strong correlation between print reading and spatial visualization. Training in this area can increase the print reader’s ability to read and interpret multiview drawings. An understanding of the visualization process will also help you under- stand how views are projected and arranged. Spatial Visualization Tools The print reader can take steps other than just looking at prints to develop an ability to visualize. This section presents a few of the many spatial visu- alization instruments available. The exercises in this unit, and in Units 6 and 7, can help beginning print readers develop the spatial skills necessary to successfully read multiview prints and drawings. Spatial visualization training has also been shown to increase the success rate of students in engi- neering and technology programs. The Purdue Spatial Visualization Test—Visu- alization of Rotations involves observing two pictorial views of a three-dimensional object. The second pictorial view shows the block rotated about a single axis or more than one axis. A different block is then to be mentally rotated in the same fashion. The correct pictorial answer is chosen from five possible answers, Figure 5-2. Many examples of this instrument can be found online. Goodheart-Willcox Publisher Figure 5-1. The views of a multiview drawing are systematically arranged so anyone can visualize the object.