Isometric Projection Drawing CHAPTER 6

Transcription

1 Isometric Projection Drawing CHAPTER 6

2 Content Overview Pictorial projection Parallel projection Axonometric projection Isometric projection Axes and selection Isometric lines and planes Isometric scale Isometric projection & Isometric drawing Producing Isometric sketches & drawing Isometric lines & non-isometric lines Circles and arcs Irregular curves Oblique projection drawing

3 6.1 Pictorial projection Pictorial projection: Not intended to give exact or true view Not intended to transmit dimensions, although sometimes dimension is useful Useful when the information and instructions to be given to nontechnical and untrained people

4 6.1 Parallel projection technique 6.1

5 6.1 Axonometric projection 6.1 axon = axis; metric = measure, in Greek Axonometric projection is a parallel projection technique to create a pictorial drawing of an object by rotating the object on an axis relative to a projection or picture plane

6 6.1 Axonometric projection 6.1 Axonometric projection Trimetric Dimetric Isometric

7 6.1 Axonometric projection 6.1

8 6.2 Isometric projection 6.2 Isometric projection is a true representation of the isometric view of an object Isometric view is created by rotating the object 45 degree about vertical axis, and tilting it forward 35 deg 16

9 6.2 Isometric projection: axes 6.2 The 3 axis meet at A,B form equal angles of 120 deg and they are called Isometric Axes OA is vertical, OB is inclined at 30deg to the right, OC is inclined at 30deg to the left Any lines parallel to these Isometric Line Any planes parallel Isometric Planes

10 6.2 Iso-lines & Iso Iso-planes

11 6.2 Selection of Isometric Axes 6.2 Main purpose of isometric view is to provide a pictorial view which reveals as much detail as possible Selection of principal edges is important Figure shows 8 isometric views of the same block

12 6.2 Selection of Isometric Axes 6.2

13 6.2 Isometric projection: scale 6.2 The tilt causes the edges & planes to become foreshortened The projected length is approximately 80% of the true length

14 Isometric projection & drawing Isometric projection & Isometric drawing Isometric projection: drawn at scale of Isometric drawing: drawn at full scale

15 Producing Isometric Sketches Begin with defining isometric axis Begin sketch by extending axes vertical lines, 30deg left & right

16 Producing Isometric Sketches Sketch an isometric box Sketch the view on each faces, starting with isometric lines Add in non-iso lines and other details Darken all visible lines.

17 Isometric angles & non-iso lines Isometric angles & non-iso lines

18 6.3 Non Non-isometric lines

19 6.3 Iso Iso-circles and arcs

20 6.3 Iso Iso-circles and arcs: sketch

21 6.3 Iso Iso-circles and arcs: cylinder

22 6.3 Partial arcs

23 6.3 Producing isometric drawing 6.3 Draw centre lines AOB and COD, O is centre of circle, AO=OB=CO=OD = radius of circle. Draw FCG and EDH parallel to AOB, draw FAE and GBH parallel to COD. Draw diagonal FOH, mark points J and K where FJ = HK = radius of circle. With centre G and rad. R1 = GA, draw an arc between GJ produced at L and GK produced at M. Similarly with centre E. With centres J and K and radius R2 = JL and KM, complete the figure.

24 6.3 Iso Iso-circles and arcs: draw

25 6.3 Iso Iso-circles and arcs: draw

26 6.3 Irregular curves in isometric 6.3

27 6.4 Producing Isometric drawing 6.4 Read the orthogonal drawing carefully, observe the scale, choose the best point where isometric axes meet to reveal as much detail as possible draw an 'isometric box' enclosing the object draw in light construction lines draw arc & curves in thick, remove excess.. line in 30 right lines line in 30 left lines line in vertical lines to complete the view

28 6.4 Producing Isometric drawing 6.4

29 6.4 Producing Isometric drawing 6.4

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31 6.5 Isometric dimensions 6.5

32 6.5 Isometric features

33 Isometric assembly: 3D render

34 6.5 Isometric exploded assembly 6.5

35 6.6 Oblique projection drawing 6.6 Oblique projection parallel projection where the projectors are parallel to each other but not perpendicular to the projection plane

36 6.6 Oblique projection drawing 6.6 The actual angle that the projectors make with the plane is not fixed, but preferably between 30deg 60deg Most common 45 degree

37 6.6 Oblique projection drawing types: Cavalier projection: true length along axis Cabinet projection: half true length General: any from half to full true length

38 6.6 Oblique projection drawing 6.6 Place complex surfaces (arcs, holes, irregular curve, etc.) parallel to front plane The longest dimension should be parallel to frontal plane

39 6.7 Producing oblique sketch 6.7

40 End of Chapter 6 THANK YOU

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