Projections & Technical Drawing

Projection A representation of a three-dimensional object in two dimensions Described by several concepts: Dimensions Edge Side Vertex

Folding Out Flaps Take the dimensions of a box Make an ISOMETRIC DRAWING of the box. Decide which side is the principal view, this is now the FRONT VIEW. Fold out the box. Which views are the most important? Three sides are shown on a Blue Print.

Folding out?

1. Multiview (Orthographic) Projections 2-D drawings representation of the different views of an object. Show a top, front, and side view of an object You must decide the principal view, which will be used as the FRONT VIEW. Length and width of object parallel to length and width of paper.

Three Views Top Front Side

Examples Regular Projection Hidden Views

Proper Blueprint

Perspective Drawing Represents the three dimensions of an object in the same view.

2. Isometric Projections A perspective drawing represents the three dimensions of an object in the same view. Principal edges of the projected object are arranged on three axes (1200) 3-D drawing that shows length, width, and height in equal proportions. Drawn to scale, measured accurately, edges are parallel to the isometric axes are exact or to scale.

3. Oblique A perspective drawing in which one of the object’s sides is parallel to the sheet of paper, but its depth is represented by parallel straight lines drawn at an oblique angle

Assignment: Read p. 343-348 Do. Workbook p.181-184