ISOMETRIC DRAWING TYPICAL CONDITION. IN THIS 3-D DRAWING OF AN OBJECT, ALL THREE DIMENSIONAL AXES ARE MENTAINED AT EQUAL INCLINATIONS WITH EACH OTHER.( 1200) IT IS A TYPE OF PICTORIAL PROJECTION IN WHICH ALL THREE DIMENSIONS OF AN OBJECT ARE SHOWN IN ONE VIEW AND IF REQUIRED, THEIR ACTUAL SIZES CAN BE MEASURED DIRECTLY FROM IT. 3-D DRAWINGS CAN BE DRAWN IN NUMEROUS WAYS AS SHOWN BELOW. ALL THESE DRAWINGS MAY BE CALLED 3-DIMENSIONAL DRAWINGS, OR PHOTOGRAPHIC OR PICTORIAL DRAWINGS. HERE NO SPECIFIC RELATION AMONG H, L & D AXES IS MENTAINED. NOW OBSERVE BELOW GIVEN DRAWINGS. ONE CAN NOTE SPECIFIC INCLINATION AMONG H, L & D AXES. ISO MEANS SAME, SIMILAR OR EQUAL. HERE ONE CAN FIND EDUAL INCLINATION AMONG H, L & D AXES. EACH IS 1200 INCLINED WITH OTHER TWO. HENCE IT IS CALLED ISOMETRIC DRAWING L D D

H Laxmi Institute of Technology, sarigam L D L H H PURPOSE OF ISOMETRIC DRAWING IS TO UNDERSTAND OVERALL SHAPE, SIZE & APPEARANCE OF AN OBJECT PRIOR TO ITS PRODUCTION. SOME IMPORTANT TERMS: ISOMETRIC AXES, LINES AND PLANES: The three lines AL, AD and AH, meeting at point A and making 1200 angles with each other are termed Isometric Axes. L D The lines parallel to these axes are called Isometric Lines. A The planes representing the faces of of the cube as well as other planes parallel to these planes are called Isometric Planes. ISOMETRIC SCALE: When one holds the object in such a way that all three dimensions are visible then in the process all dimensions become proportionally inclined to observers eye sight and hence appear apparent in lengths. This reduction is 0.815 or 9 / 11 ( approx.) It forms a reducing scale which Is used to draw isometric drawings and is called Isometric scale. In practice, while drawing isometric projection, it is necessary to convert

true lengths into isometric lengths for measuring and marking the sizes. This is conveniently done by constructing an isometric scale as described on next page. H TYPES OF ISOMETRIC DRAWINGS ISOMETRIC VIEW ISOMETRIC PROJECTION Drawn by using True scale ( True dimensions ) Drawn by using Isometric scale ( Reduced dimensions ) 4 D 3 H UE R T 1 L D . 1 ISOM 0 0

LE S TH 2 NG 300 H C 4 3 2 THS NG LE 450 A B Isometric scale [ Line AC ] required for Isometric Projection D L CONSTRUCTION OF ISOM.SCALE. From point A, with line AB draw 300 and 450 inclined lines AC & AD resp on AD. Mark divisions of true length and from each division-point draw vertical lines upto AC line. The divisions thus obtained on AC give lengths on isometric scale.

1 AS THESE ALL ARE 2-D FIGURES WE REQUIRE ONLY TWO ISOMETRIC AXES. D H RECTANGLE A D D L A L C D C A B C B

B B IF THE FIGURE IS FRONT VIEW, H & L 1 AXES ARE REQUIRED. H TRIANGLE B 3 1 A 3 IF THE FIGURE IS TOP VIEW, D & L AXES ARE REQUIRED. 2 Shapes containing Inclined lines should be enclosed in a rectangle as shown. Then first draw isom. of that rectangle and then inscribe that shape Isometric view if the Shape is F.V. or

T.V. SHAPE ISOMETRIC OF PLANE FIGURES A B L 3 L A D 1 2 2 4 H PENTAGON E 1 4 D A

E 1 D B C 3 D E A D C 2 4 2 B 3 L 3 L 1 C A 2

B STUDY Z ILLUSTRATIONS 2 DRAW ISOMETRIC VIEW OF A CIRCLE IF IT IS A TV OR FV. B FIRST ENCLOSE IT IN A SQUARE. ITS ISOMETRIC IS A RHOMBUS WITH D & L AXES FOR TOP VIEW. THEN USE H & L AXES FOR ISOMETRIC WHEN IT IS FRONT VIEW. FOR CONSTRUCTION USE RHOMBUS METHOD SHOWN HERE. STUDY IT. 4 C 2 2 C D 1 D 1

A 4 3 3 B A 3 STUDY Z ILLUSTRATIONS 25 R DRAW ISOMETRIC VIEW OF THE FIGURE SHOWN WITH DIMENTIONS (ON RIGHT SIDE) CONSIDERING IT FIRST AS F.V. AND THEN T.V. 50 MM IF FRONT VIEW 100 MM IF TOP VIEW ISOMETRIC OF PLANE FIGURES AS THESE ALL ARE 2-D FIGURES WE REQUIRE ONLY TWO ISOMETRIC

AXES. SHAPE IF F.V. IF T.V. 4 HEXAGON CIRCLE IF THE FIGURE IS FRONT VIEW, H & L AXES ARE REQUIRED. IF THE FIGURE IS For Isometric of Circle/Semicircle use Rhombus method. Construct Rhombus TOP VIEW, D & L of sides equal to Diameter of circle always. ( Ref. topic ENGG. CURVES.) AXES ARE SEMI CIRCLE REQUIRED. For Isometric of Circle/Semicircle use Rhombus method. Construct it of sides equal to diameter of circle always. ( Ref. Previous two pages.) 5 STUDY Z ILLUSTRATIONS ISOMETRIC VIEW OF PENTAGONAL PYRAMID STANDING ON H.P.

(Height is added from center of pentagon) ISOMETRIC VIEW OF BASE OF PENTAGONAL PYRAMID STANDING ON H.P. 4 4 D E D 1 C A 2 B D E L 3 D L 1 3 C

A B 2 6 STUDY Z ILLUSTRATIONS ISOMETRIC VIEW OF PENTAGONALL PRISM LYING ON H.P. 4 H E 1 D A C ISOMETRIC VIEW OF HEXAGONAL PRISM STANDING ON H.P. 2 B 3

L 7 STUDY Z ILLUSTRATIONS CYLINDER STANDING ON H.P. CYLINDER LYING ON H.P. 8 STUDY Z ILLUSTRATIONS HALF CYLINDER STANDING ON H.P. ( ON ITS SEMICIRCULAR BASE) HALF CYLINDER LYING ON H.P. ( with flat face // to H.P.) STUDY Z ILLUSTRATIONS 60 FV X 40 Y

20 TV ISOMETRIC VIEW OF A FRUSTOM OF SQUARE PYRAMID STANDING ON H.P. ON ITS LARGER BASE. 9 STUDY ILLUSTRATION 10 ISOMETRIC VIEW OF FRUSTOM OF PENTAGONAL PYRAMID PROJECTIONS OF FRUSTOM OF PENTAGONAL PYRAMID ARE GIVEN. DRAW ITS ISOMETRIC VIEW. SOLUTION STEPS: FV FIRST DRAW ISOMETRIC OF ITS BASE. y x 1 E

4 THEN DRAWSAME SHAPE AS TOP, 60 MM ABOVE THE BASE PENTAGON CENTER. D THEN REDUCE THE TOP TO 20 MM SIDES AND JOIN WITH THE PROPER BASE CORNERS. A TV 40 20 40 B 60 20 60 2 C 3 ISOMETRIC VIEW OF A 11 FRUSTOM OF CONE STANDING ON H.P. ON ITS LARGER BASE. STUDY Z ILLUSTRATIONS

60 FV X 40 Y 20 TV PROBLEM: A SQUARE PYRAMID OF 30 MM BASE SIDES AND 50 MM LONG AXIS, IS CENTRALLY PLACED ON THE TOP OF A CUBE OF 50 MM LONG EDGES.DRAW ISOMETRIC VIEW OF THE PAIR. 50 30 STUDY Z ILLUSTRATIONS 50 12 13 STUDY Z ILLUSTRATIONS PROBLEM: A TRIANGULAR PYRAMID OF 30 MM BASE SIDES AND 50 MM

LONG AXIS, IS CENTRALLY PLACED ON THE TOP OF A CUBE OF 50 MM LONG EDGES. DRAW ISOMETRIC VIEW OF THE PAIR. c a p o b a p b SOLUTION HINTS. TO DRAW ISOMETRIC OF A CUBE IS SIMPLE. DRAW IT AS USUAL. BUT FOR PYRAMID AS ITS BASE IS AN EQUILATERAL TRIANGLE, IT CAN NOT BE DRAWN DIRECTLY.SUPPORT OF ITS TV IS REQUIRED. SO DRAW TRIANGLE AS A TV, SEPARATELY AND NAME VARIOUS POINTS AS SHOWN. AFTER THIS PLACE IT ON THE TOP OF CUBE AS SHOWN. THEN ADD HEIGHT FROM ITS CENTER AND COMPLETE ITS ISOMETRIC AS SHOWN. o c STUDY Z ILLUSTRATIONS FV 30 10 30 30 D

50 + 50 TV PROBLEM: A SQUARE PLATE IS PIERCED THROUGH CENTRALLY BY A CYLINDER WHICH COMES OUT EQUALLY FROM BOTH FACES OF PLATE. ITS FV & TV ARE SHOWN. DRAW ISOMETRIC VIEW. 14 15 STUDY Z ILLUSTRATIONS FV PROBLEM: A CIRCULAR PLATE IS PIERCED THROUGH CENTRALLY BY A SQUARE PYRAMID WHICH COMES OUT EQUALLY FROM BOTH FACES OF PLATE. ITS FV & TV ARE SHOWN. DRAW ISOMETRIC VIEW. 30 10 30 40 SQUARE TV

60 D 16 STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. 10 20 40 FV 40 X Y TV 50 D 30 D STUDY ILLUSTRATIONS Z ct io Is oDi re 300

Isom. Scale r R r P C r R r n 450 R r 17 ISOMETRIC PROJECTIONS OF SPHERE & HEMISPHERE r C R R r P TO DRAW ISOMETRIC PROJECTION OF A HEMISPHERE

P C = Center of Sphere. P = Point of contact R = True Radius of Sphere r = Isometric Radius. TO DRAW ISOMETRIC PROJECTION OF A SPHERE 1. FIRST DRAW ISOMETRIC OF SQUARE PLATE. 2. LOCATE ITS CENTER. NAME IT P. 3. FROM PDRAW VERTICAL LINE UPWARD, LENGTH r mm AND LOCATE CENTER OF SPHERE C 4. C AS CENTER, WITH RADIUS R DRAW CIRCLE. THIS IS ISOMETRIC PROJECTION OF A SPHERE. Adopt same procedure. Draw lower semicircle only. Then around C construct Rhombus of Sides equal to Isometric Diameter. For this use iso-scale. Then construct ellipse in this Rhombus as usual And Complete Isometric-Projection of Hemi-sphere. 18 PROBLEM: A HEMI-SPHERE IS CENTRALLY PLACED ON THE TOP OF A FRUSTOM OF CONE. DRAW ISOMETRIC PROJECTIONS OF THE ASSEMBLY. Z r 50 D r

R 30 D r 50 P 50 D FIRST CONSTRUCT ISOMETRIC SCALE. USE THIS SCALE FOR ALL DIMENSIONS IN THIS PROBLEM. 450 R r 300 STUDY ILLUSTRATIONS STUDY Z ILLUSTRATIONS 19 A SQUARE PYRAMID OF 40 MM BASE SIDES AND 60 MM AXIS IS CUT BY AN INCLINED SECTION PLANE THROUGH THE MID POINT OF AXIS AS SHOWN.DRAW ISOMETRIC VIEW OF SECTION OF PYRAMID. 3 4 4 12

3 X Y a 1 d 1 2 4 o b 2 3 c 20 STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. 50 X O

Y 20 25 O 25 20 21 STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. 35 FV 35 x 10 O 20 10 40 70

O TV 30 y STUDY Z ILLUSTRATIONS 22 F.V. & T.V. and S.V.of an object are given. Draw its isometric view. FV 30 10 30 SV 30 10 30 x y TV ALL VIEWS IDENTICAL STUDY Z

ILLUSTRATIONS 24 F.V. & T.V. and S.V.of an object are given. Draw its isometric view. ALL VIEWS IDENTICAL FV SV y x 10 40 40 60 60 TV STUDY Z ILLUSTRATIONS F.V. & T.V. and S.V.of an object are given. Draw its isometric view. 25 ALL VIEWS IDENTICAL FV SV y

x 10 40 40 60 TV 60 26 F.V. & T.V. and S.V.of an object are given. Draw its isometric view. ORTHOGRAPHIC PROJECTIONS FRONT VIEW L.H.SIDE VIEW 20 20 x 20 O y 50 20 30 20

20 TOP VIEW 20 O STUDY Z ILLUSTRATIONS 27 STUDY Z ILLUSTRATIONS F.V. and S.V.of an object are given. Draw its isometric view. 30 SQUARE 40 20 50 20 10 O 30 F.V. O

60 S.V. 28 STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. FV 40 10 O 45 30 D 10 50 O 80 TV STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. 40

FV O X 10 Y 100 10 25 TV 10 30 10 25 O 30 R 20 D 29 STUDY Z ILLUSTRATIONS 30 F.V. & T.V. of an object are given. Draw its isometric view.

30 FV RECT. SLOT 10 50 35 10 X O 20 D TV 60 D 30 D O Y 31 STUDY Z ILLUSTRATIONS F.V. and S.V.of an object are given. Draw its isometric view. 10

25 15 25 40 10 25 25 O O 80 F.V. 25 S.V. STUDY Z ILLUSTRATIONS 32 F.V. & T.V. of an object are given. Draw its isometric view. 450 30 FV 40

X Y O 30 D TV 40 O 40 15 33 STUDY Z ILLUSTRATIONS F.V. and S.V.of an object are given. Draw its isometric view. HEX PART 30 20 20 40 O 20 50

20 15 O 100 30 60 STUDY Z ILLUSTRATIONS F.V. & T.V. of an object are given. Draw its isometric view. 34 40 20 F.V. 30 10 X Y O 10 30 10 30

O 80 T.V. F.V. and S.V.of an object are given. Draw its isometric view. 10 10 35 STUDY Z ILLUSTRATIONS 15 25 25 X Y O 50 FV 10 LSV 36 NOTE THE SMALL CHZNGE IN 2ND FV & SV.

DRAW ISOMETRIC ACCORDINGLY. 10 X Y O FV LSV 37 STUDY Z ILLUSTRATIONS F.V. and S.V.of an object are given. Draw its isometric view. 30 10 20 20 15 10 15 O 30 15 X

O 15 Y 50 F.V. LEFT S.V. 38 STUDY Z ILLUSTRATIONS F.V. and S.V.of an object are given. Draw its isometric view. 30 10 60 30 O O 40 40 F.V. S.V.