review of descriptive geometry
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Review of Descriptive Geometry. Lecture 10. Topics For Today. Quiz – CAEG – AutoCAD Drawing Number 18 is due Lab report due on Wednesday at the beginning of the lab period - PowerPoint PPT PresentationTRANSCRIPT
Lect 10 P. 1
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
Review of Descriptive Geometry
Lecture 10
Lect 10 P. 2
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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
Lect 10 P. 3
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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.
Lect 10 P. 4
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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.
Lect 10 P. 5
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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
Lect 10 P. 6
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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 don’t overwrite the blank3D file.
Lect 10 P. 7
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
Key to Descriptive Geometry
Top
FrontRight Side
Know the location of the origin (0,0,0)
Lect 10 P. 8
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
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
Lect 10 P. 9
Engineering H191 - Drafting / CAD
Autumn Quarter Gateway Engineering Education Coalition
Today’s 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