Lect 10P. 1

1
Topics For Today

• Quiz CAEG AutoCAD
• Drawing Number 18 is due
• Lab report due on Wednesday at the beginning of
  the lab period
• Lab Report Follow the example, calc. at each
  speed, graph in , use two mph groupings (24 and
  25 avg 24.5) or three mph groupings (24 thru 26
  -- avg 25)
• Descriptive Geometry
• Read BTG Chapter 11

2
Review from Monday

• Lines and planes extend to infinity while we work
  with a small portion which we define.
• Lines and planes can be extended.
• Dihedral angle The angle between two planes
  smaller of the two. It can be found by finding
  the line of intersection and looking at the line
  of intersection as a point.
• Angle between a line and plane This requires a
  view in which the plane is an edge and the line
  is true length.

3
Review from Monday

• Downloaded a blank3d template 4 viewports,
  3D construction, world coordinates, cursor
  tracking world
• Layout mode Transferring the model to paper
  tab at the bottom of screen
• The layout and the model or construction mode are
  all part of one file.

4
Review from Monday

• VIEW Using UCS menu
• 3 UCS plan (enter) (enter) gives true size of
  plane
• Z UCS plan (enter) (enter) gives end view of
  line which could provide edge view of a plane or
  a dihedral angle

5
Construction Hint

• When you have created a line and then look down
  the line so the line appears as a point, it
  disappears in AutoCAD. When you know this is
  going to happen, place a point () at each end of
  the line.
• Save often but dont overwrite the blank3D file.

6
Key to Descriptive Geometry
Top
Know the location of the origin (0,0,0)
Front
Right Side
7
Angle between a line and plane

• Required a view where the line is true length
  and the plane is an edge
• In pencil construction, three auxiliary views
  are required 1) edge view of plane 2) true size
  of plane 3) edge view of plane and true length of
  line
• Using the UCS menu and the PLAN command shortens
  the process

8
Todays Assignment

• Dwg 19 SGAC-4-1
• Angle between a line and a plane in space
• Due at end of class today
• Read Handout steps for solving problems in
  AutoCAD are provided
• Dwg 20 SGAC-4-2
• Dihedral Angles
• Due at beginning of next lecture
• Read Handout steps for solving problems in
  AutoCAD are provide