Front, Top, Side Holes & Curves Isometric Engineering Drawing Front, Top, Side Holes & Curves Isometric

Why do we need to learn to draw? Technical Drawing: the practice or skill of portraying objects in a precise way using certain techniques. Technical Drawings tell us the following: Shape Size of Objects Types of material that object is constructed of Finish of Objects Assembly Engineers are confronted with the task of communicating the design, development and structures of machines to manufacturers and builders. The shape and size of various parts of a machine and its structure must be recorded on plane sheets in a systematic way for communication. The pictorial view of the object does not carry all the details, especially the inner details and correct shape of complicated parts. Different methods, therefore, are implied for describing the exact shape based on the ‘projectors’ drawn by engineers.   

Types of Drawings We’ll Cover Orthographic/Multiview Pictorial Orthographic Shows objects “true” shape Does not look like a “picture” Two Dimensional Pictorial Looks like a picture 3-D Realistic

Orthographic Generating Multi-view Drawings 6 Views of an Object

Eliminate the Unnecessary When we draw objects, we should only include the views that are needed to fully describe the object Shape of the object Shape of features When we draw, convention is to use the right side view over the left side view if they both show the object equally well Likewise, the top view is preferred to the bottom view if they both show the object equally well Showing only the necessary views saves time, makes the drawing less cluttered, and makes the drawing easier to interpret

Multi-view Setup Primary Views: top, front, right side Secondary Views: Left side, rear, bottom There is always one dimension in common between adjacent views 4 angles of projection. Third angle projection is the multi-view setup used by the U.S.A. First angle projection is used in Europe.

Let Us Practice Creating a Three-view sketch: Step 1: Block in the front, top, and right side views. Sketch the front view first using construction lines to project dimensions Step 2: Lightly block the major features in views Step 3: Use construction lines to project the location and size of features between views Step 4: Finish adding the final lines Let Us Practice Step-by-step

LINES!

Hidden Lines Lines with short, evenly spaced, dashes Indicate edges that you cannot see in a view

Center Lines Thin lines of alternating, long and short, dashes Show centers of holes and axes of symmetry

Dimension Lines

Extension Lines

Order of Precedence Visible Lines Hidden Lines Center Lines Practice!

Creating an Isometric Drawing