Multiview Sketching Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Multiview Sketching Introduction to Engineering Design © 2012 Project Lead The Way, Inc. Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing 2D view of a 3D shape There are always six principal 2D views of a 3D object Front, back, top, bottom, left and right Left view Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Multiview Drawings (Orthographic Drawings or Orthographic Projection Drawings) Shows two or more two-dimensional views of a three-dimensional object. Provides 2D shape drawing of an object. When combined other with dimensions, the drawings serve as the main form of communication between designers and manufacturers. Blueprints Ortho means straight; rectangular; upright. Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing The six principal views of orthographic Projection drawings (Multiview drawings or orthographic drawing) Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing The six principal views of orthographic Projection drawings (Multiview drawings) or orthographic drawing Project Lead The Way, Inc. Copyright 2007

Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection Orthographic Projection is the easiest technique used to create multiview drawings. Orthographic Projection is the projection of the features of an object onto an imaginary plane. Plane is a flat surface that goes on forever but has no depth The projection of the features from the object to the plane is made by lines of sight that are perpendicular to the imaginary plane. Perpendicular meets at 90 degree angles Project Lead The Way, Inc. Copyright 2007

Orthographic Projection (Glass Box Method) Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection (Glass Box Method) The best way to understand orthographic projection (glass box method) is to imagine an object contained inside a glass box. Project Lead The Way, Inc. Copyright 2007

Orthographic Projection (Glass Box Method) Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection (Glass Box Method) There is a total of six glass walls surrounding the object. Each wall represents a projection plane onto which a two- dimensional object view will be created. Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Projection Plane Also referred to as a plane of projection or picture plane, is an imaginary surface that exists between the viewer and the object. The projection plane is the surface onto which a two-dimensional view of a three-dimensional object is projected and created. Project Lead The Way, Inc. Copyright 2007

Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection Start by focusing only on the front projection plane. A person standing in front of the object would see only the five corners identified in black. 2 3 1 4 line of sight at 90° angle to projection plane 5 Project Lead The Way, Inc. Copyright 2007

Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection Projection lines are used to project each corner outward until they reach the projection plane. Project Lead The Way, Inc. Copyright 2007

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Projection Line An imaginary line that is used to locate or project the corners, edges, and features of a three-dimensional object onto an imaginary two-dimensional surface. Project Lead The Way, Inc. Copyright 2007

Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection The visible edges of the object are then identified on the projection plane by connecting the projected corners with object lines. Project Lead The Way, Inc. Copyright 2007

Orthographic View Selection Recommendations for how to select the front view Most natural position or use Shows best shape and characteristic contours Longest dimensions Fewest hidden lines Most stable and natural position

Orthographic View Selection Best shape description No hidden edges Longest dimension Most natural position BEST FRONT VIEW

Orthographic Projection Visually Explained Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection Visually Explained http://faculty.gvsu.edu/karpenm/melissa/glassboxindex.html Project Lead The Way, Inc. Copyright 2007

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Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Multiview Drawing All three-dimensional objects have width, height, and depth. Width is associated with an object’s side-to-side dimension. Height is associated with an object’s top-to-bottom dimension. Depth is associated with an object’s front-to-back dimension. Project Lead The Way, Inc. Copyright 2007

Multiview Drawing TOP VIEW FRONT VIEW RIGHT-SIDE VIEW Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Multiview Drawing TOP VIEW FRONT VIEW RIGHT-SIDE VIEW Project Lead The Way, Inc. Copyright 2007

Multiview Drawing 45° Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Multiview Drawing 45° Project Lead The Way, Inc. Copyright 2007

Sketching a Multiview Drawing Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Sketching a Multiview Drawing Given the overall dimensions of the object, a pencil, and a sheet of graph paper, sketching a multiview drawing can be easily done using points, construction lines, and object lines. Project Lead The Way, Inc. Copyright 2007

Sketching a Multiview Drawing Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Sketching a Multiview Drawing Step 1 – Layout the boxes within which the individual views will occur using points and construction lines. TOP FRONT RIGHT SIDE Project Lead The Way, Inc. Copyright 2007

Sketching a Multiview Drawing Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Sketching a Multiview Drawing Step 2 – Use construction lines between the views to indicate the geometry of the views. Project Lead The Way, Inc. Copyright 2007

Sketching a Multiview Drawing Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Sketching a Multiview Drawing Step 3 – Identify the visible edges with object lines. Project Lead The Way, Inc. Copyright 2007

Sketching a Multiview Drawing Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Sketching a Multiview Drawing Step 4 – Locate hidden lines. Project Lead The Way, Inc. Copyright 2007

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Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Orthographic Projection Orthographic projection drawing have six principal view. But in most case three or less are needed. Project Lead The Way, Inc. Copyright 2007

Number of views needed Orthographic Projection Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing Number of views needed Orthographic Projection 6 views are rarely needed. Want the least views necessary to show the details of the object Want the least views necessary to dimension the drawing Don’t dimension to hidden lines, in that case add another view. The less views the better but if you really need another view to get a good feel of what the object is you can Project Lead The Way, Inc. Copyright 2007

All six views are not always needed Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing All six views are not always needed LEFT SIDE RIGHT SIDE FRONT All 6 views are normally not needed. Here is only 4 views but the right and left are mirror images. So we can get rid of the left. Note that hidden lines are not shown for simplicity. Do you think the view chosen for the Front View is the best choice? Why or why not? Left view is not needed. It is a reflection of the right view. So engineers don’t want extra drawings. Just the bare minimum Remember the recommendations for how to choose a front view: Most natural position or use Shows best shape and characteristic contours Longest dimensions Fewest hidden lines Most stable and natural position An argument can be made for using what would be the Left Side view <click> for the Front View in that it shows the characteristic shape of the chair, but the Front View shown in the slide provides a better view of the decorative wood work on the back of the chair. Either view would suffice as a front view. Dining Chair Project Lead The Way, Inc. Copyright 2007

A cylinder only really needs one view. But it can be done with two. Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing A cylinder only really needs one view. But it can be done with two. 5.0 4.0 4.0 5.0 Two view One view Project Lead The Way, Inc. Copyright 2007

Number of Orthographic Projections One View is needed Some cylindrical shapes Uniform thickness or shape two views would be identical All dimensions properly and easily shown on one view depth

Number of Orthographic Projections Two Views Symmetrical part Second view is necessary for depth since all depth is not constant A third view would be identical to another one All detail and dimensions fit on two

2 views are minimum but three show the details are better Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing 2 views are minimum but three show the details are better Project Lead The Way, Inc. Copyright 2007

3 views are needed Historical example: Leonard P. Karr (1913–1995) What is this object? Do you think Mr. Karr aligned his drawing correctly?

Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing A Question… Each of the blocks at the right has the same overall dimensions and color. What else do they have in common? Project Lead The Way, Inc. Copyright 2007

They all have identical top views! Multiview Sketching Introduction to Engineering Design Unit 2 Technical Sketching and Drawing A Question… They all have identical top views! Project Lead The Way, Inc. Copyright 2007