DFTG-1305 Technical Drafting Prepared by Prof. Francis Ha Session 4 Multiview Projection (or Orthographic Projection) Reading: Geisecke’s textbook: 13th Ed. Chapter 4 – p.92 14th Ed. Chapter 5 – p.162 Update: 13-0612 Copyright ©2006 by K. Plantenberg Restricted use only Engineering Graphics What is Engineering Graphics? A set of rules and guidelines that helps you to create an Engineering Drawing. What is an Engineering Drawing? A drawing that communicates an idea or design. Copyright ©2006 by K. Plantenberg Restricted use only Engineering Graphics Examples of Engineering Drawings → Mechanical Drawings • Detailed drawing of a part that needs to be machined. → Electromechanical Drawings • Schematic Diagram – Enclosing design • Printed Circuit Board layout & design → Civil Drawings • Road layout and construction • Bridge, freeway plans → Pipe Process Drawings • Plant processing, pipelines • Oil refineries and energy facilities Copyright ©2006 by K. Plantenberg Restricted use only Architecture Drawings Summary What will we learn in this Chapter? → How to create a multiview projection Key points → A multiview projection is a 2-D representation of a 3-D object. Copyright ©2006 by K. Plantenberg Restricted use only Introduction Multiview projection is a 2-D drawing representing a 3-D object. Copyright ©2006 by K. Plantenberg Restricted use only Introduction A Multiview projection represents different sides of an object. Copyright ©2006 by K. Plantenberg Restricted use only The Six Principle Views The 6 principle views are created by looking at the object, straight on, in the directions indicated. Copyright ©2006 by K. Plantenberg Restricted use only Multiview Projection We will discuss the details of 1. Glass Box Method 2. Standard Views 3. Function of views 4. Lines Type and Line Weight 5. Rules for Line Creation and Use. Copyright ©2006 by K. Plantenberg Restricted use only Multiview Projection 1. The Glass Box Method Copyright ©2006 by K. Plantenberg Restricted use only The Glass Box Method How do we create the six principle views? → Glass Box method: • The object is placed in a glass box. • The image of the object is projected on the sides of the box. • The box is unfolded. • The sides of the box are the principle views. Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method The object is placed in a glass box. The sides of the box represent the 6 principle planes. Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method The image of the object is projected on the sides of the box. Top view: Rhombus: equal sides Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method Things to notice: → The projection planes. → The projectors. → How surfaces A and B are projected. Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method The box is unfolded creating the 6 principle views. Top view: Rhombus: equal sides Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method Copyright ©2006 by K. Plantenberg Restricted use only Glass Box Method Copyright ©2006 by K. Plantenberg Restricted use only Exercise 1-1 Label the five principle views with the appropriate view names. Copyright ©2006 by K. Plantenberg Restricted use only Exercise 1-1 Principle Views In-class Practice Copyright ©2006 by K. Plantenberg Restricted use only Name each view Name each view. Top Name each view. Top Name each view. Top Right Side Name each view. Top Right Side Name each view. Top Right Side Rear Name each view. Top Right Side Rear Name each view. Top Left Side Right Side Rear Name each view. Top Right Side Rear Copyright ©2006 by K. Plantenberg Restricted use only Name each view. Top Left Side Right Side Rear Bottom Conclusion Copyright ©2006 by K. Plantenberg Restricted use only Top What are the differences between the Right Side and Left Side views? Left Side Right Side Rear Right & Left Sides Bottom Top What are the differences between the Right Side and Left Side views? Left Side Right Side Rear They are mirror -images with one different line type. Bottom What are the differences between the Top and Top Bottom, and Front and Rear views? Left Side Right Side Rear Top and Bottom Views Bottom What are the differences between the Top and Top Bottom, and Front and Rear views? Left Side Right Side Rear They are mirror-images with different line types. Bottom Which view(s) has the least amount of hidden or dashed lines? Top Left Side Right Side Rear Bottom Which view(s) has the least amount of hidden or dashed lines? Top Left Side Right Side Rear Front and Top Views Bottom You must put the view names at the bottom of each view. Copyright ©2006 by K. Plantenberg Restricted use only Multiview Projection 1. Glass Box Method 2. Standard Views Copyright ©2006 by K. Plantenberg Restricted use only Standard Views When constructing a multiview projection, we need to include enough views to completely describe the true shape of the part. → Complex drawing = more views → Simple drawing = less views Copyright ©2006 by K. Plantenberg Restricted use only Standard Views The standard views used in a multiview projection are: → Front view → Top view → Right side view If any of the remaining views doesn’t add any new information, ignore it. Copyright ©2006 by K. Plantenberg Restricted use only Standard Views How many views do we need to completely describe a block? Copyright ©2006 by K. Plantenberg Restricted use only Standard Views How many views do we need to completely describe a block? Copyright ©2006 by K. Plantenberg Restricted use only Standard Views How many views do we need to completely describe a block? Two views. The 3rd view TOP duplicates information. FRONT (No need) Copyright ©2006 by K. Plantenberg Restricted use only Standard Views How many views do we need to completely describe a sphere? Copyright ©2006 by K. Plantenberg Restricted use only Standard Views How many views do we need to completely describe a sphere? One view. Why? A sphere has only one dimension. It’s the diameter. Copyright ©2006 by K. Plantenberg Restricted use only Multiview Projection 1. Glass Box Method 2. Standard Views 3. Function of views Copyright ©2006 by K. Plantenberg Restricted use only Front View The front view shows the most features or characteristics of the object. → It usually contains the least amount of hidden lines. → The front view is chosen first and the other views are based on the orientation of the front view. Copyright ©2006 by K. Plantenberg Restricted use only View Alignment The top and front views are aligned vertically and share the same width dimension. The front and right side views are aligned horizontally and share the same height dimension. Copyright ©2006 by K. Plantenberg Restricted use only Multiview Projection 1. Glass Box Method 2. Standard Views 3. Function of views 4. Line Type and Line Weight Copyright ©2006 by K. Plantenberg Restricted use only Line Type and Line Weight Line type and line weight provide valuable information to the print reader. For example, line type and weight can answer the following questions. → Is the feature visible or hidden from view? → Is the line part of the object or part of a dimension? → Is the line indicating symmetry? Copyright ©2006 by K. Plantenberg Restricted use only Line Type and Weight There are four commonly used line types: → Continuous _________________ (Visible) → Hidden _ _ _ _ _ _ _ _ _ _ _ _ → Center ___ _ ___ _ ___ _ __ → Phantom ___ _ _ ___ _ _ ____ Copyright ©2006 by K. Plantenberg Restricted use only Line Type and Weight Some lines are more important than others. Importance is indicated by line weight or thickness. → The thicker the line, the more important it is. Copyright ©2006 by K. Plantenberg Restricted use only Line Types Visible lines: → Visible lines represent visible edges and boundaries. → Continuous and thick → (0.5 or 0.7 mm, B or BB type). Copyright ©2006 by K. Plantenberg Restricted use only Line Types Hidden lines: → Hidden lines represent edges and boundaries that cannot be seen. → Dashed and medium thick → (0.3mm, HB). Copyright ©2006 by K. Plantenberg Restricted use only Line Types Center lines: → Represent axes of symmetry on a circle or cylinder. → Long dash – short dash and thin (0.3 mm, HB). Copyright ©2006 by K. Plantenberg Restricted use only Line Types Phantom line: → Phantom lines are used to indicate imaginary features. • alternate positions of moving parts. • adjacent positions of related parts. → The line type is long dash – short dash – short dash and the line weight is usually thin (0.3 mm, HB). Copyright ©2006 by K. Plantenberg Restricted use only Exercise 1-2 Line types Copyright ©2006 by K. Plantenberg Restricted use only Skip to next part of the exercise Exercise 1-2 Draw a visible, hidden, center and phantom line. Visible line Center line Hidden line Phantom line Copyright ©2006 by K. Plantenberg Restricted use only Skip to next part of the exercise Exercise 1-2 Draw a visible, hidden, center and phantom line. Copyright ©2006 by K. Plantenberg Restricted use only Line Types More on Center lines: → Important for interpreting cylindrical shapes. → Crossed center lines should be drawn at the centers of circles. Copyright ©2006 by K. Plantenberg Restricted use only Line Types More on Center lines: → They are also used to indicate circle of centers and paths of motion. Copyright ©2006 by K. Plantenberg Restricted use only Line Types Dimension and Extension lines: → Dimension and extension lines are used to show the size of an object. • In general, a dimension line is placed between two extension lines and is terminated by arrowheads, which indicates the direction and extent of the dimension.