Innovation and Inventions Unit 2 ETP 2006 – Jeff Pegg This material is based upon work supported the National Science foundation under Grant No Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the view of the National Science Foundation (NFS).

Drafting is frequently called a “UNIVERSIAL LANGUAGE” because it communicates ideas in graphic or picture form. Like other languages, symbols that have special and specific meanings are used to accurately describe the shape, size, type of material, finish and fabrication of an object. The symbols have been standardized over most of the world making it possible to interpret and understand drawings made in other countries. Drafting is the part of industry concerned with the preparation of drawings needed to develop and manufacture modern-day products. We will be doing Mechanical Drawing, which means we will be using tools to complete the drawings.

Drawing from “Exploring drafting basic fundamentals” John R. Walker

Any object in nature has how many sides? 6 What are the views?

Top FrontBack Bottom Left Side Right Side The three (3) that we will use are Front, Top and Right Side.

Measuring If your drawings are to be made accurate, you must be able to make accurate measurements. The ruler that we will be using is measured to 1/16 of an inch. I know that most of you could measure something that is 4 inches long.

But what happens when the measurement is less that one inch? You will see that there are smaller lines between the Inch marks.

We will be going from the largest marks (1 Inch) to the smallest marks ( 1/16 of an inch) on a ruler. As we are going from the largest to smallest each time we are dividing the number by ½. So we will take the 1 inch mark and make it into a fraction. Which is 1/1 and we will divide it by 2. Or take the fraction and multiply by 1/2 1/1X1/2= 1/2

The next shortest line is ½ X ½ = ¼.

The next shortest line is ¼ X ½ = 1/8.

The smallest line that we will use is: 1/8 x ½ = 1/16

Basic drawing that you will be doing. 1.Orthographic projection (Three View) 2.Pictorial A.Isometric B.Oblique (Cavalier) C.Perspective (One Point)

Orthographic Projection. Permits a three-dimensional object to be drawn on a flat sheet of paper having only two dimensions.

Pictorial Drawings A pictorial drawing shows the likeness of the object as viewed by the eye.

Isometric Drawings An isometric drawing shows an object as is. All lines which show the width and depth are drawn full length. Also Isometric drawing are drawn to the 3 base lines which are 30 degrees to the left, 30 degrees to the right and vertical or 90 degrees.

Oblique Pictorial Drawings An Oblique drawing is a pictorial drawing similar to an isometric drawing, except one surface, the longest dimension or front is parallel to the picture plane (and is drawn in true shape and size). There are three types of Oblique drawings 1.Cavalier Oblique - depth axis lines are drawn at full scale. 2.Cabinet Oblique – depth axis lines are drawn at one- half scale. 3.General Oblique – depth axis lines vary from one-half to full scale. The angle is usually 45 degrees.

Perspective Drawings Perspective drawing is a drawing used by an Architect, Artist, or Draftsman to show an object as it would appear to the eye from a certain location. There are two types of perspective drawings: 1.One point perspective. 2.Two point perspective. There is one major point or points used. These are called vanishing points. All lines are drawn to vanish points. A perspective drawing is like standing on a road and looking at the horizon and the road looks like it comes together, but it doesn’t.

To draw the depth, select one line measure the depth and then draw a vertical and horizontal line to the other depth lines.

To draw the depth, measure on depth axis and the draw a line vertical and the other point to the vanishing point.

Standards: Standard 8: Students will develop an understanding of the attributes of design. Benchmark E Design is a creative process that leads to useful products and systems. Standard 9: Students will develop an understanding of engineering design. Benchmark F Design involves a set of steps, which can be preformed in different sequences and repeated if needed. Standard 11: Students will develop abilities to apply the design process. Benchmark H Apply a design process to solve problems in and beyond the laboratory- classroom. Benchmark J Make two-dimensional and three-dimensional representations of the designed solution.