Chapter 5: Orthographic Views

Agenda 3 Views of an Object Projection between Views Hidden lines and precedence Demonstration Compound Lines Oblique Surfaces Rounded Surfaces Holes, in slanted surfaces

Visualization Ability to look at a 3D object and mentally see the appropriate 2D orthographic views Ability to look at a 2D ortho drawing and mentally picture the 3D object This class is going to develop that skill

Line Types Visible Line Hidden Line Center Line Dimension Line Construction Line

Visible

Linetype Precedence

Demonstration We’ll tackle our first multi-view drawing First we’ll set up layers for – hidden, center, construction, and final lines We’ll draw the overall layout Then we’ll fill in the details Transfer construction lines into final lines

Layers and Linetypes Click on Object Properties Tool – change color, linetype, lineweight  by layer – Layer Properties Manager (ObjPrp or Format) New, name = hidden, New, name = center Click on Hidden Layer line, select color and LT – Load hidden and center if necessary, choose Can turn a layer on/off (lightbulb), scale linetypes Draw on different layers – Switch with Layer control tool – Make Object’s layer current – Select object, switch layer LCT, 2x(esc)

Mod: Cut a Channel Cut channel thru bottom of object Use hidden lines to show channel Work on 1 st two problems in A4.doc

Demonstration II This drawing has a number of slanted surfaces intersecting in ways that need additional care to portray accurately

Oblique Surfaces Not shown “true” in any view Hard to visualize, must rely on projection

Rounded Surfaces

Holes Holes viewed head on need center lines Holes viewed sideways need hidden and centerlines Holes into slanted surfaces become ellipses in some views. Use projection to create bounding rectangle, fill in with ellipse