Intersection and Development

8/18/2019 Intersection and Development

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Engineering Drawing(MEng 6201)

Chapter Seven

Intersection andDevelopment

Ad!ra"a# A$



Introd!ction to Development

• Development is the outside surface of ageometric form laid at. Parts designed tobe produced from at materials are cut froma pattern that is drawn as development. In

development, the complete unfolded layoutdrawing of a part showing the total surfacearea in one view is constructed from truelength dimensions; and his at plane

drawing shows each surface of the part astrue shape.

• In development, all surfaces of the object areconnected along their adjacent bend lines.




• Sheet metal objects, cardboard packaging,large diameter cylindrical vessels and piping,funnels, cans, and ducts are just some ofobjects made from developments.

• he actual developed at sheetcon!guration is to cut according to itsdeveloped pattern. hen the !nal operationsinclude bending, folding or rolling, and

stretching the part to its re"uired design.

• he four most common shapes that can beaccurately developed include prism,

pyramid, cylinder and cone.







• #n object is normally developed by unfolding or unrolling its surfaces onto the plane of thepaper. he actual drawing of the objectconsists of showing each successive surface

as true shape and connected along commonedges.

• $or cone and cylinder bending lines are notre"uired whereas for prism and pyramid

bending lines are re"uired to represent theedges.

• %ach of the parts is developed as an inside&

up pattern drawing 'it is unfolded(unrolled so



%&pes o' Development

• here are four types which theclassi!cation is based on the shape ofthe surface and the method employedto construct its development.

• he four types development are*

+. Parallel line

. -adial line

. riangulation

/. #ppro0imation




• arallel line* used for objects that arecomposed of parallel straight line elementsor edges* such as cylinders and prisms.




• adial line* used for objects whose edgesor elements de!ne triangular surface areas*such as pyramids and cones.




• %riang!lation* is a means of developing asurface by breaking it into a series oftriangle. he objects made by a combinationof curved and plan surfaces are developed

by triangulation.




• Appro*imation* used for objects whosesurfaces can not be truly developed* such asspherical shapes.



Development o' a rism

• # prism can be right prism 'that makesan angle 12o with the hori3ontal) orobli"ue 'that makes an angle di4erentfrom 12o with the hori3ontal); can be

full prism or truncated; and can behollow prism or solid. In development,hollow prisms are considered.

• In development of a prism, the length and the height of the developedsurface are the perimeter of the cross&

section and the edge heights of a




5evelopment of a right prism.




5evelopment of a truncated right prism.




5evelopment of an obli"ue prism.



Development o' a C&linder

• # cylinder can be right cylinder 'that

makes an angle 12o with thehori3ontal) or obli"ue 'that makes anangle di4erent from 12o with the

hori3ontal); can be full cylinder ortruncated; and can be hollow cylinderor solid. In development, hollow

cylinders are considered.• In development of a cylinder, the

length and the height of the developed

surface are the circumference 'pie i.e.



Development o' a C&linder

5evelopment of a right cylinder.




5evelopment of a truncated right

cylinder.





cylinder.




5evelopment of an obli"ue cylinder.




5evelopment of an obli"ue cylinder.



Development o' a Cone

• # cone can be right cone 'that makes

an angle 12o with the hori3ontal) orobli"ue 'that makes an angle di4erentfrom 12o with the hori3ontal); can be

full cone, frustum or truncated; andcan be hollow cone or solid. Indevelopment, hollow cones are

considered.• In development of a cone, the area of

the developed surface is the sector

made by the circumference and




5evelopment of a right cone.




5evelopment of a frustum right cone.




5evelopment of a truncated right cone.




5evelopment of an obli"ue cone.



Development o' a &ramid

• # pyramid can be right pyramid 'that

makes an angle 12o with thehori3ontal) or obli"ue 'that makes anangle di4erent from 12o with the

hori3ontal); can be full pyramid,frustum or truncated; and can behollow pyramid or solid. In

development, hollow pyramids areconsidered.

• In development of a pyramid, the area

of the developed surface is the sum of




5evelopment of a right pyramid.




5evelopment of a frustum right

pyramid.





pyramid.





pyramid.




5evelopment of an obli"ue pyramid.



Development o' a ectang!lar toCirc!lar %ransition iece

• his type of object is made by acombination of curved and plan surfaces. It is developed by breaking it

into a series of triangles.



Development o' a ectang!lar toCirc!lar %ransition iece



Development o' a Sphere

• # sphere is made up of wrappedsurfaces. It is developed by twoappro0imation method namely, goremethod and 3one method.




5evelopment of a sphere by gore

method.




5evelopment of a sphere by 3one

method.



Development o' a Comined +,ects

• 5evelopment of a combined objects applied

the following* # combination of two prisms,combination of two cylinders, a combinationof two cones, a combination of twopyramids, a combination of a prism and a

cylinder, a combination of a prism and acone, a combination of a prism and apyramid, a combination of a cylinder and acone, a combination of a cylinder and apyramid and combination of a cone and apyramid.

• Some of the development of a combined

objects are shown with e0amples.




5evelopment of a combination of two

prisms.





cylinders.





cylinders.



Introd!ction to Intersection

• 7hen two surface, either plane or curved,

meet a line formed common to both calledline o' intersection.

• 8ine of intersection can be formed by a

combination of two prisms, combination oftwo cylinders, a combination of two cones, acombination of two pyramids, a combinationof a prism and a cylinder, a combination of a

prism and a cone, a combination of a prism and a pyramid, a combination of a cylinder and a cone, a combination of a cylinder anda pyramid and combination of a cone and a

pyramid.



Introd!ction to Intersection

• wo object can be intersect at angle of 12o

'right intersection) or at an angle di4erentfrom 12o 'obli"ue intersection); and can beintersect symmetrically or asymmetrically.

-ine o' Intersection etween



-ine o' Intersection etween%wo risms

8ine of intersection between two prisms right angle to each

other&symmetrical.





8ine of intersection between two prisms right angle to each

other&asymmetrical.





8ine of intersection between two prisms obli"ue angle to

each other.




-ine o' Intersection etween%wo C&linders

8ine of intersection between two cylinders right angle to

each other.




-ine o' Intersection etween%wo C&linders

8ine of intersection between two cylinders obli"ue to

each other.

-ine o' Intersection etween a Cone



-ine o' Intersection etween a Coneand a C&linder

-ine o' Intersection etween a Cone



-ine o' Intersection etween a Coneand a rism

-ine o' Intersection etween a



-ine o' Intersection etween aC&linder and a rism

-ine o' Intersection etween a



-ine o' Intersection etween aSphere and a rism

-ine o' Intersection etween a Sphere



-ine o' Intersection etween a Sphereand a C&linder

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Intersection and Development