Isometric Projection Drawing CHAPTER 6

Isometric Projection Drawing CHAPTER 6

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

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

6.1 Parallel projection technique 6.1

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

6.1 Axonometric projection 6.1 Axonometric projection Trimetric Dimetric Isometric

6.1 Axonometric projection 6.1

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

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

6.2 Iso-lines & Iso Iso-planes

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

6.2 Selection of Isometric Axes 6.2

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

6.2 6.2 Isometric projection & drawing Isometric projection & Isometric drawing Isometric projection: drawn at scale of 0.816 Isometric drawing: drawn at full scale

6.3 6.3 Producing Isometric Sketches Begin with defining isometric axis Begin sketch by extending axes vertical lines, 30deg left & right

6.3 6.3 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.

6.3 6.3 Isometric angles & non-iso lines Isometric angles & non-iso lines

6.3 Non Non-isometric lines

6.3 Iso Iso-circles and arcs

6.3 Iso Iso-circles and arcs: sketch

6.3 Iso Iso-circles and arcs: cylinder

6.3 Partial arcs

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.

6.3 Iso Iso-circles and arcs: draw

6.3 Iso Iso-circles and arcs: draw

6.3 Irregular curves in isometric 6.3

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

6.4 Producing Isometric drawing 6.4

6.4 Producing Isometric drawing 6.4

6.5 Isometric dimensions 6.5

6.5 Isometric features

6.5 6.5 Isometric assembly: 3D render

6.5 Isometric exploded assembly 6.5

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

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

6.6 Oblique projection drawing 6.6 3 types: Cavalier projection: true length along axis Cabinet projection: half true length General: any from half to full true length

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

6.7 Producing oblique sketch 6.7

End of Chapter 6 THANK YOU