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Isometric Projection

Isometric Projection Isometric projections A cube shown with this type of projection pivots 45 to show two faces on the projection plane instead of a single face.It is then tilted frontward or backward, allowing three faces to be observed.2Important Terms

ContentOverview.Pictorial projectionParallel projectionAxonometric projectionIsometric projection.Axes and selectionIsometric lines and planesIsometric scaleIsometric projection & Isometric drawingProducing Isometric sketches & drawing.Isometric lines & non-isometric linesCircles and arcsIrregular curvesOblique projection drawing. Pictorial projectionPictorial 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 non-technical and untrained people.Hidden lines are not shown in isometric drawing.

Axonometric projectionaxon = axis; metric = measure, in GreekAxonometric 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

Axonometric projectionTrimetric.Dimetric.Isometric.

Axonometric projection Isometric projectionIsometric 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.

Isometric projection: axesThe 3 axis meet at A,B form equal angles of 120 deg and they are called Isometric AxesOA is vertical, OB is inclined at 30deg to the right, OC is inclined at 30deg to the leftAny lines parallel to these Isometric LineAny planes parallel Isometric Planes

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

Draw the isometric projection of a rectangle of 100mm and 70mm sides if its plane is (a) Vertical and (b) Horizontal.

To draw the isometric projection of a square planeConstruction Case:Vertical plane Draw a line at 30 to the horizontal and mark the isometric length on it.Draw verticals at the ends of the line and mark the isometric length on these parallel lines.Join the ends by a straight line which is also inclined at 30 to the horizontal. There are two possible positions for the plane.

Isometric Projection of Planes

Case:Horizontal plane Draw two lines at 30 to the horizontal and mark the isometric length along the line.Complete the figure by drawing 30 inclined lines at the ends till the lines intersect. Note(i) The shape of the isometric projection or drawing of a square is a Rhombus. (ii) While dimensioning an isometric projection or isometric drawing true dimensional values only must be used.

*The figure below shows how the cases can be executed.

Isometric angles & non-isometric linesExample of producing non-isometric lines.The position of point Z is obtained in the isometric view, by transferring the distance of X and Y.

Iso-circles and arcs: drawDrawing isometric circles and arcs using four-centre method.

Drawing iso-circles

To draw an iso-circle, on left plane, Diameter 20mm

Draw centre lines, vertical & 30deg to left.Draw (construction line) 20mm square box. The centre lines should divide each side by half.(c) Draw straight lines; 1-2 & 1-3 and 2-5 & 2-6.(d) Point 7 is the intersection between line 1-2 & 2-5, and similarly point 8, 1-3 & 2-6 on the other side.(e) Set your compass to the distance 7-2, draw an arc with centre at point 7, from point 2 to point 5. Do the same on the other side.(f) Set your compass to the distance 1-2, draw an arc with centre (1), from (2) to (3).(a)1234567825456(b)(c)(d)(e)(f) Producing Isometric ProjectionRead multi-view drawing given.Observe scale, dimension, projection. angleDetermine front, side & top view.Try to visualize how the object looks like.Start with sketching, do not draw straight away.If not sure, start with sketching an isometric box, enclosing the whole object.You can label points, lines and surfaces on multi-view to help visualization.

6.3 Sketching isometric cylinderStart by drawing the bounding box.The front end of the cylinder is sketched using the previous technique.The far end of the cylinder is a partial iso-circle. Sketch until meeting the tangent with the two straight lines.

6.3 Sketching partial arcs

Isometric ProjectionORTHOGRAPHIC MULTI-VIEW PROJECTION

ISOMETRIC PROJECTIONConstruction box How to draw an object containing rounded parts21

The EndTHANK YOU Department : Mechanical M-1 (B-Batch).Created by : Parth P. Prajapati.