chapter 13
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Chapter 13. Orthographic Sketching. Describing an Angle Bracket. Orthographic Projection. Orthographic drawings represent three dimensional objects in three separate views arranged in a standard manner. Orthographic Views. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 13
Orthographic Sketching
Describing an Angle Bracket
Orthographic ProjectionOrthographic drawings represent three dimensional objects in three separate views arranged in a standard manner.
Orthographic ViewsYou can adequately describe most objects with three orthographic views. Front Top Right
Converting to Orthographic
Orthographic Views –Line Types
Line Types
Visible LineHidden LineCenter LineDimension LineConstruction Line
Line Types
Sketching Techniques
Engineering Drawing SkillsLetteringLine TypesOrthographic ViewsPatience
See the example drawings in the notes.
Engineering Drawing RulesAlways use a Pencil.Make all lettering the same size.Use Engineering or Drafting Paper.
Orthographic ViewsYou can adequately describe most objects with three orthographic views. Front Top Right
Sketching techniquesUse very light construction lines“Box in” the rough outline of the objectDarken only the lines you wish to keepClean up the edges and rough spots
Orthographic Projection
2 Dimensional projections on Orthogonal planesShow lines based on change of plane or change of materialUse multiple linetypes Visible Hidden Center
Describing an Angle Bracket
A relatively simple objectPictorial view may be difficult
Glass Box concept
Envision the object surrounded in a glass boxProject the views out onto the pieces of glassEach pane shows a 2D projection of the object
Completed Orthographics
Projection Planes
The three panes of glass represent the principal orthographic planes Horizontal Frontal ProfileEach plane illustrates two of the principal dimensions: Height, Width, and Depth
Class Exercise
As a team you have 3 minutes to discuss the following:What dimensions are contained on each of the principal projection planes?
The Glass Box Approach
Orthographic Projection
Opening the Box
Final Views
Six Orthographic Views
Laying Out All Six Views
Three Primary Views
View SelectionIf the object has an obvious top, then it must be the top viewMinimize the number of hidden linesUse the most descriptive view as the front viewConserve space by choosing the depth to be the smallest dimension
Precedence of Lines
Construction of Views
Must align orthographic viewsWidth appears in Top and FrontHeight appears in Front and SideDepth appears in Side and TopHeight and width project directlyDepth must be projected via a 45° angle
Steps in Creating the Three-View Sketch
Step 1 - Lightly Block Three Views
Use very light lines
for drawing in
the constructio
n lines
Step 2 - Lightly Block Major Features
Step 3 - Add Features, Use Miter Line
Steps in Creating the Three-View SketchStep 4 - Add Final Lines
Steps in Creating the Three-View SketchCompleted Sketch
Think-Pair-ShareIn the next 1 minute as an Individual if you could ask a question . . . specifically what don’t you understand about today’s topic what would it be. [at least 3 items should be listed]Now take 2 minutes to merge your list with the person sitting next to you AND add 1 new item to the listIn the next 5 minutes share the results with the other half of your team, delete questions that you can answer for each other, AND prioritize the remaining questions your list
Team Exercise
Complete three orthographic views of the object shown on the next slide.Include visible, hidden, and center lines where appropriate.Use the grid paper in the back of your book or your engineering sketch pad.You will be given 7 minutes.
Object for exercise