1. Construction Lines and Rays (Xlines) Sacramento City College Engineering Design Technology Construction Lines (XLines)1

2. 2 Drawing Construction Lines u Construction lines u are used for layout purposes. u They are not part of the drawing. u They are “not the object that is being drawn”. u Are equivalent to “guidelines” or “layout lines” in manual drafting u They are drawn very lightly by the drafter so they do not reproduce.

3. Construction Lines (XLines)3 Drawing Construction Lines u AutoCAD has two types of construction lines u XLINES u RAYS u Both can be used for similar purposes. u XLINE has more options and flexibility.

4. Construction Lines (XLines)4 The XLINE Command

5. Construction Lines (XLines)5 The XLINE Command u XLINE command u creates XLINE objects. u An XLINE object u is an infinite length line u designed for use as a construction line.

6. Construction Lines (XLines)6 The XLINE Command u XLINES u do not change the Drawing Extents. u do not affect zooming operations.

7. Construction Lines (XLines)7 The XLINE Command u XLINES can be modified by u Moving u Copying u Trimming and u Other editing operations.

8. Construction Lines (XLines)8 XLINES u TRIM and FILLET change the object type. u If one end is trimmed, an XLINE becomes a RAY. u A RAY becomes an “ordinary” LINE

9. Construction Lines (XLines)9 XLINES u To access XLINES u Pick Construction Line button in the Draw toolbar. u Pick Construction Line in the Draw pull-down menu. u type XL or XLINE at the Command: prompt.

10. Construction Lines (XLines)10 Drawing Construction Lines u The following XLINE Options are available: u From point u Hor u Ver u Ang u Bisect u Offset

11. Construction Lines (XLines)11 Drawing Construction Lines u XLINE Options: From Point u Specify two points that the construction line passes through. u The first point = the root point. u After the root point is picked, the Through point prompt allows you to pick as many points as you like. u XLINES are created between every point picked and the root point.

12. Construction Lines (XLines)12 Drawing Construction Lines u XLINE Options: Hor - horizontal line u Draws a horizontal construction line through a single specified point. u The line is automatically drawn horizontal and you only have to pick one point. u Every time you click the mouse, a Horizontal XLine is drawn.

13. Construction Lines (XLines)13 Drawing Construction Lines u XLINE Options: Ver - vertical line u Draws a vertical construction line through the specified point. u The line is automatically drawn vertical you only have to pick one point. u Every time you click the mouse, a Vertical XLine is drawn.

14. Construction Lines (XLines)14 Drawing Construction Lines u XLine Options: Ang - line at a specific angle u Draws a construction line at a specified angle through a specified point. u 45 degrees, 30 degrees, etc. u The line is automatically drawn at the angle you specify u You only have to pick one point. u Every time you click the mouse, an XLine is drawn at that angle.

15. Construction Lines (XLines)15 Drawing Construction Lines u XLINE Options: u Bisect - draws a construction line that bisects a specified angle u XLINE Options: u Offset - draws a construction line at a specified distance from a selected line object

16. Construction Lines (XLines)16 Using XLINES - Special Considerations

17. Construction Lines (XLines)17 XLINES Layer u XLINES and RAYS u Are drawn on the current layer. u Plot the same as other objects. u It is best to set up a special layer for construction lines.

18. Construction Lines (XLines)18 XLINES Color u Set construction lines to a color that is “background”. u Recommended color: RED u A little difficult to see, makes them “stay out of your way.”

19. Construction Lines (XLines)19

20. Construction Lines (XLines)20 Rays

21. Construction Lines (XLines)21 XLINES to RAYS u A RAY is considered to be semi-infinite because it is infinite in one direction only. u If the infinite end of a ray is trimmed off it becomes a LINE object.

22. Construction Lines (XLines)22 RAY Command u The RAY command is limited compared to the XLINE command. u The command allows you to specify the point of origin and a point the ray passes through u Ray extends in one direction only

23. Construction Lines (XLines)23 RAY Command u The RAY command can be accessed by: u Picking RAY in the Draw pull-down menu. u Typing RAY at the Command: prompt.

24. Construction Lines (XLines)24 XLINES and RAY Commands u Neither the XLINE or the RAY command allow you to UNDO a construction line that you have already drawn.