Orthographics in AutoCAD

1. Orthographics in AutoCAD Class 3.2: Multi-view Drawings

2. Readiness Assessment Test 3.2.1 • As a team, respond to the following question. You will be given 2 minutes: • Name the six principal orthographic views.

3. Learning Objectives • Name the three principle projection planes and the dimensions that each one shows • Use AutoCAD to create orthographic views of objects • Know the correct line weights for printing drawings from AutoCAD

4. Orthographic Projection • 2 Dimensional projections on Orthogonal planes • Show lines based on change of plane or change of material • Use multiple linetypes • Visible • Hidden • Center

5. Describing a “Step Wedge” • A relatively simple object • Pictorial view may be difficult

6. Glass Box Concept • Envision the object surrounded by a glass box • Project the views out onto the glass panes • Each pane shows a 2D projection of the object

7. Projection Planes • The three panes of glass represent the principal orthographic planes • Horizontal • Frontal • Profile • Each plane illustrates two of the principal dimensions of: HEIGHT, WIDTH or DEPTH

8. Readiness Assessment Test 3.2.2 • Individually respond to the following question. You will be given 1 minute: • Name the six principal orthographic views and the dimensions each shows.

9. Class Exercise • As a team you have 3 minutes to discuss the following: • What dimensions are contained on each of the principal projection planes?

10. Converting to Orthographics • By unfolding the box, you generate the FRONT, TOP, and RIGHT SIDE views • Others (Back, Bottom, Left Side) could also be created if needed

11. Completed Orthographics

12. Choice of Orthographic Views • If the object has an obvious top, then it must be the top view • Minimize the number of hidden lines • Use the most descriptive view as the front view • Conserve space by choosing the depth to be the smallest dimension

13. Linetypes • Visible (0.6 mm) • Hidden (0.3 mm) • Center (0.3 mm) • Construction (0)

14. Precedence of Lines • When lines coincide with each other, the more important lines take precedence over the other lines. The order of precedence is: • Visible • Hidden • Center

15. Paired Exercise • Sketch three orthographic views of the object shown on the next slide. • Include visible, hidden, and centerlines where appropriate. • Use the grid paper from the back of your workbook or your engineering sketch pad.

16. Object for Exercise

17. Drawing setup SNAP GRID Display control ZOOM PAN Drawing LINE DTEXT CIRCLE ARC Editing and inquiry ERASE DDEDIT TRIM FILLET UNDO Modify properties Grips General Concepts Layers Ortho Mode AutoCAD commands Review

18. Entering AutoCAD • Log on to the network • Double click on AutoCAD icon • Select Use a Template • Find drawing templateE09C.dwt • Select OK

19. Status line at the bottom • The status line at the bottom of the display tells you whether any of the modes are on or off. • The “pressed” modes are on. (SNAP, GRID, ORTHO and MODEL in the picture below) • These are saved with the computer, so if your drawing does not have the correct modes selected, please modify the choices as shown below.

20. Working with Layers • Layers are used to control the type of line that will be drawn • They are pre-defined on the templates used for this class • They are accessed from a dropdown list as shown to the right

21. Display Control • ZOOM -- scales the screen view to an area of the drawing surface • “Window” will zoom down to a window • “All” will zoom out to show the larger of the drawn entities or limits • Realtime allows you to shrink or enlarge the display in real time. • PAN -- moves around on the drawing surface

22. Drawing Objects Line • Drawing commands are found on the toolbar located at the left of the screen • The four of interest today are Line, Arc, Circle, and Mtext • These may be abbreviated from the keyboard using the first letter(s) (e.g.) • Line - L • Arc - A • Circle - C • Mtext - MT Arc Circle Mtext

23. Completing the Title Strip • Rather than using the MTEXT command to compete the title block, it is simpler to edit the existing text. • The command to do this is DDEDIT, or find “Text…” under the Modify pulldown menu. • Or you can double click on the text to be edited.

24. Formats of Keyboard Coordinates • Either absolute or relative • Absolute -- references origin of drawing (0,0) • Relative -- references previously selected point • Absolute is the default • Precede relative coordinates with an @ sign • @10,20 or @ 10<45 • Direct Distance • Enter a distance in the direction of the cursor and return

25. Paired Exercise • Start a new drawing. • Use template E09c.dwt • You have 15 minutes to complete as many of the drawings as possible • Save your solutions on a floppy disk.

26. Printing in AutoCAD • Printing is done via the PLOT command • Always plot limits • Set origin to “Center the Plot” • Always plot at a scale appropriate to the drawing (normally 1:1) • ALWAYS GET A FULL PREVIEW BEFORE PRINTING

27. Plot Device Settings • Under Plot Device, make sure the printer is selected and the Plot Style Table is set to “endg105.ctb”. • Select the printer for the room you are in.

28. Homework