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Chapter 03 orthographic convention
- 1. Chapter 3Chapter 3 Conention PracticeConvention Practice in Orthographicin Orthographic WritingWriting
- 2. TOPICS Definition Purposes Purposes Types of conventions - Alternate position of side view - Incompleted viewp - Aligned view - Enlarged viewEnlarged view - Non-existing intersection line - Cylinder intersectionCylinder intersection
- 3. DEFINITION Convention is acommonly accepted practices which disregard some strict rules of orthographic projection. More readable M lti ie Object multiview representation Multiview representation Projection’ s rules Convention practices Disregard some rules p
- 4. EXAMPLE : Alreadymet convention practice Front view Using a dash line for ti th hidd d CONVENTION PRACTICErepresenting the hidden edge. PRACTICE
- 5. PURPOSES To improve theclarity of a drawingTo improve the clarity of a drawing. T f ilit t th di i iTo facilitate the dimensioning. To reduce the drafting effort. To save or efficiently use a drawing space.space.
- 6. TYPES OF CONVENTION PRACTICE 1Al i i f id i CONVENTION PRACTICE 1. Alternate position of side view 2 I l t d i2. Incompleted view 2 1 Incompleted side view2.1 Incompleted side view 2.2 Partial view 2.3 Half view 2.4 Local view
- 7. TYPES OF CONVENTION PRACTICECONVENTIONPRACTICE 3. Aligned view 4. Enlarged view 5. Non-existing intersection line 6. Intersection : Hole on a cylinder
- 8. ALTERNATE POSITION OFALTERNATEPOSITION OF SIDE VIEWSIDE VIEW
- 9. ALTERNATE POSITION OFSIDE VIEW Purposes To save drawing space. To improve the clarity of a drawing.p y g Conventional practice Whenever the height of an object is small and the Conventional practice depth is relatively large, places the side view beside the top view.p
- 10.
- 11. Example New orientation ofviews still agree with 3rd angle system. Slot becomesS ot beco es more readable. Hole becomes more readable.
- 12. INCOMPLETED SIDE VIEWINCOMPLETEDSIDE VIEWINCOMPLETED SIDE VIEWINCOMPLETED SIDE VIEW
- 13. DEFINITION Incompleted side viewsare side views that are eliminated a feature that can not clearly seen from a selected viewing direction.g
- 14. Example : Strictlyorthographic projection. Principal viewLeft-side view Right-side view Details are interfered by thoseDetails are interfered by those on the opposite view. Difficult to read and to dimension.
- 15. Example : Incompletedside views Incompleted left-side view Incompleted right-side viewPrincipal view Better describe an object andBetter describe an object and facilitate dimensioning.
- 16. Example : Incompletedside views representation Principal view
- 17. PARTIAL VIEWPARTIAL VIEW HALFVIEWHALF VIEW LOCAL VIEWLOCAL VIEW
- 18. DEFINITION Partial view isa view that represents portions of the part that have a features need to clarify. H lf i i ti l i th t i ill t t d lHalf view is a partial view that is illustrated only half of the part. Local view is a view that shows only features d t l ifneed to clarify.
- 19. Example : Partialviews Clearly seen a shape.
- 20. Example : Halfview Left half Right half Center line acts as a line of symmetry. No continuous line !No continuous line ! Symmetry symbol Thin lineThin line (4H)
- 21. Example : Halfview : alternative representation Half view can be made by drawing the views slightly beyond the line of symmetry.slightly beyond the line of symmetry. No symmetry symbolsymbol. It is allow for writing a break linea break line. Thin line (4H) In this course, we it th b k li ( ) omit the break line.
- 22. Example : Halfview : two symmetry axes
- 23. Example : Localview Sh f thShape of the slot is completely shown. R6 7 Easy for dimensioningR6 dimensioning
- 24. ALIGNED VIEWALIGNED VIEWALIGNEDVIEWALIGNED VIEW
- 25. DEFINITION Align view isa view that is drawn by imaginarily rotating the object’s features, appeared in a principle view about symmetry axis.principle view about symmetry axis.
- 26. Example : Necessityof align view Strictly Projection Apply conventionconvention Confuse Clear Waste of time
- 27. CONVENTION PRACTICE For anobject that has symmetrical positioned features, it is advisable to show them on adjacent view in true size at true radial distance from the symmetry axis.
- 28. Example : Alignview of holes Given ApplyApply aligned conventionconvention Gives the impression that there is a hole at the center of the plate.
- 29. Example : Alignview of holes Given ApplyApply aligned conventionconvention Gives the impression that holes are at unsymmetrical position.
- 30. Example : Alignview of holes Apply aligned convention
- 31. Example :Example :Align view of ribs Apply aligned convention
- 32. Example : Alignview of ribs & holes Apply aligned convention
- 33. Example : Alignview of ribs & holes & keyway Make Orthographic Projectiong p j Apply Convention
- 34. Example : Alignview
- 35. ENLARGED VIEWENLARGED VIEWENLARGEDVIEWENLARGED VIEW
- 36. DEFINITION Enlarged view isa view partly selected from full view and is drawn with a larger scalefull view and is drawn with a larger scale. Conventional practice At full view, the selected portion is framed by Conventional practice continuous thin line and having a name. F l d i it t b ifi d b thFor an enlarged view, it must be specified both name and scale used.
- 37. Example : Enlargedview Full view Enlarged viewFull view Enlarged view or A A (3:1) A (3:1)Reference position ScaleScale
- 38. NON-EXISTING LINE OFNON-EXISTINGLINE OF INTERSECTIONINTERSECTION
- 39. DEFINITION Non-existing line ofintersection is the line of intersecting surfaces that are eliminated by filletsintersecting surfaces that are eliminated by fillets and rounds. Wh t j ti i l d th t ti Conventional practice When true projection mislead the representation of an object, it is necessary to show the additional lines that are projected from the actual intersection of the surfaces as if the fillets and rounds were not present.
- 40. Example : Non-existingline of intersection Obj t d t hObject does not has rounds and fillets Edges of the surfaces are shown as lines inare shown as lines in the top view.
- 41. Example : Non-existingline of intersection Obj t h The view looks like a plate Object has rounds and fillets The view looks like a plate with a hole !! C i i i d !Convention practice required ! Construct a non-existing line of No edge ! intersection. No edge ! (No intersection between surfaces)
- 42. Example : Non-existingline of intersection
- 43. INTERSECTION BETWEEN FILLET ANDROUNDFILLET AND ROUND Runout
- 44. INTERSECTION BETWEEN FILLET ANDROUNDFILLET AND ROUND
- 45. TO DRAW ARUNOUT R R/3 R Tangent point about 1/8 of circle R/3 Tangent point about 1/8 of circle R = radius of fillet or round
- 46. INTERSECTION BETWEEN ROUND PLANESURFACEROUND PLANE SURFACE
- 47.
- 48. HOLE IN CYLINDER Largehole : True projection
- 49. HOLE IN CYLINDER Largehole : True projection Small hole : Convention