eng drawing

7/25/2019 Eng Drawing

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Q.No.1:

Computer-aided design(CAD) is the use of computersystems to aid in

the creation, modication, analysis, or optimization of a design.[1]CADsoftare is used to increase the producti!ity of the designer, impro!e the

"uality of design, impro!e communications through documentation, and to

create a data#ase for manufacturing.[$]CAD output is often in the form of

electronic lesfor print, machining, or other manufacturing operations.

Computer%aided design is used in many elds. &ts use in designing electronic

systems is 'non as electronic design automation, or EDA. &n mechanical

design it is 'non as mechanical design automation (MDA) or computer-

aided design(CAD), hich includes the process of creating a technicaldraingith the use of computer softare.[]

CAD softare for mechanical design uses either !ector%#ased graphics to

depict the o#ects of traditional drafting, or may also produce raster

graphicsshoing the o!erall appearance of designed o#ects. *oe!er, it

in!ol!es more than ust shapes. As in the

manual draftingof technicaland engineering draings, the output of CAD

must con!ey information, such as materials, processes, dimensions,

and tolerances, according to application%specic con!entions.

CAD may #e used to design cur!es and gures in to%dimensional($D)

space+ or cur!es, surfaces, and solids in three%dimensional(D) space.[]

CAD is an important industrial arte-tensi!ely used in many applications,

including automoti!e, ship#uilding, and aerospace industries, industrial and

architectural design, prosthetics, and many more. CAD is also idely used to

produce computer animationfor special eectsin mo!ies, ad!ertisingand

technical manuals, often called DCC digital content creation. /he modern

u#i"uity and poer of computers means that e!en perfume #ottles and

shampoo dispensers are designed using techni"ues unheard of #y engineers

of the 102s. 3ecause of its enormous economic importance, CAD has #een

a maor dri!ing force for research in computational geometry, computer

graphics(#oth hardare and softare), and discrete dierential geometry.[4]
https://en.wikipedia.org/wiki/Computerhttps://en.wikipedia.org/wiki/Designhttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-1https://en.wikipedia.org/wiki/Computer-aided_design#cite_note-2https://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttps://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttps://en.wikipedia.org/wiki/Electronic_design_automationhttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-3https://en.wikipedia.org/wiki/Raster_graphicshttps://en.wikipedia.org/wiki/Raster_graphicshttps://en.wiktionary.org/wiki/draftinghttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Engineering_drawinghttps://en.wikipedia.org/wiki/Dimensionhttps://en.wikipedia.org/wiki/Engineering_tolerancehttps://en.wikipedia.org/wiki/2D_computer_graphicshttps://en.wikipedia.org/wiki/3D_computer_graphicshttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-4https://en.wikipedia.org/wiki/Industrial_artshttps://en.wikipedia.org/wiki/Prosthesishttps://en.wikipedia.org/wiki/Computer_animationhttps://en.wikipedia.org/wiki/Special_effecthttps://en.wikipedia.org/wiki/Advertisinghttps://en.wikipedia.org/wiki/Digital_content_creationhttps://en.wikipedia.org/wiki/Computational_geometryhttps://en.wikipedia.org/wiki/Computer_graphicshttps://en.wikipedia.org/wiki/Computer_graphicshttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-5https://en.wikipedia.org/wiki/Designhttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-1https://en.wikipedia.org/wiki/Computer-aided_design#cite_note-2https://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttps://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttps://en.wikipedia.org/wiki/Electronic_design_automationhttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-3https://en.wikipedia.org/wiki/Raster_graphicshttps://en.wikipedia.org/wiki/Raster_graphicshttps://en.wiktionary.org/wiki/draftinghttps://en.wikipedia.org/wiki/Technical_drawinghttps://en.wikipedia.org/wiki/Engineering_drawinghttps://en.wikipedia.org/wiki/Dimensionhttps://en.wikipedia.org/wiki/Engineering_tolerancehttps://en.wikipedia.org/wiki/2D_computer_graphicshttps://en.wikipedia.org/wiki/3D_computer_graphicshttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-4https://en.wikipedia.org/wiki/Industrial_artshttps://en.wikipedia.org/wiki/Prosthesishttps://en.wikipedia.org/wiki/Computer_animationhttps://en.wikipedia.org/wiki/Special_effecthttps://en.wikipedia.org/wiki/Advertisinghttps://en.wikipedia.org/wiki/Digital_content_creationhttps://en.wikipedia.org/wiki/Computational_geometryhttps://en.wikipedia.org/wiki/Computer_graphicshttps://en.wikipedia.org/wiki/Computer_graphicshttps://en.wikipedia.org/wiki/Computer-aided_design#cite_note-5https://en.wikipedia.org/wiki/Computer


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/he design of geometric modelsfor o#ect shapes, in particular, is

occasionally called computer-aided geometric design

Computer%aided design is one of the many tools used #y engineers and

designers and is used in many ays depending on the profession of the userand the type of softare in "uestion.

CAD is one part of the hole Digital 5roduct De!elopment (D5D) acti!ity

ithin the 5roduct 6ifecycle 7anagement(567) processes, and as such is

used together ith other tools, hich are either integrated modules or stand%

alone products, such as8

Computer%aided engineering(CA9) and :inite element analysis(:9A)

Computer%aided manufacturing(CA7) including instructions

to Computer ;umerical Control(C;C) machines

5hoto realistic renderingand 7otion sing four properties

hich are history, features, parameterization, and high le!el constraints. /he

construction history can #e used to loo' #ac' into the model?s personal

features and or' on the single area rather than the hole model.

5arameters and constraints can #e used to determine the size, shape, andother properties of the dierent modeling elements. /he features in the CAD

system can #e used for the !ariety of tools for measurement such as tensile

strength, yield strength, electrical or electro%magnetic properties. Also its

stress, strain, timingor ho the element gets aected in certain

temperatures, etc.
https://en.wikipedia.org/wiki/Geometric_modelhttps://en.wikipedia.org/wiki/Product_Lifecycle_Managementhttps://en.wikipedia.org/wiki/Computer-aided_engineeringhttps://en.wikipedia.org/wiki/Finite_element_analysishttps://en.wikipedia.org/wiki/Computer-aided_manufacturinghttps://en.wikipedia.org/wiki/Computer_Numerical_Controlhttps://en.wikipedia.org/wiki/Rendering_(computer_graphics)https://en.wikipedia.org/wiki/Revision_controlhttps://en.wikipedia.org/wiki/Product_Data_Managementhttps://en.wikipedia.org/wiki/Product_Data_Managementhttps://en.wikipedia.org/wiki/Timing_closurehttps://en.wikipedia.org/wiki/Geometric_modelhttps://en.wikipedia.org/wiki/Product_Lifecycle_Managementhttps://en.wikipedia.org/wiki/Computer-aided_engineeringhttps://en.wikipedia.org/wiki/Finite_element_analysishttps://en.wikipedia.org/wiki/Computer-aided_manufacturinghttps://en.wikipedia.org/wiki/Computer_Numerical_Controlhttps://en.wikipedia.org/wiki/Rendering_(computer_graphics)https://en.wikipedia.org/wiki/Revision_controlhttps://en.wikipedia.org/wiki/Product_Data_Managementhttps://en.wikipedia.org/wiki/Product_Data_Managementhttps://en.wikipedia.org/wiki/Timing_closure


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Computer-aided manufacturing(CAM) is the use of computer softare to

control machine toolsand related machinery in the manufacturingof

or'pieces.[1][$][][][4]/his is not the only denition for CA7, #ut it is the most

common+[1]CA7 may also refer to the use of a computer to assist in all

operations of a manufacturing plant, including planning, management,

transportation and storage.[][@]&ts primary purpose is to create a faster

production process and components and tooling ith more precise

dimensions and material consistency, hich in some cases, uses only the

re"uired amount of ra material (thus minimizing aste), hile

simultaneously reducing energy consumption.[citation needed]CA7 is no a

system used in schools and loer educational purposes. CA7 is a

su#se"uent computer%aided process after computer%aided design(CAD) and

sometimes computer%aided engineering(CA9), as the model generated in

CAD and !eried in CA9 can #e input into CA7 softare, hich then controls

the machine tool.

/raditionally, CA7 has #een considered as a numerical control(;C)

programming tool, here in to%dimensional ($%D) or three%dimensional (%D)

models of components generated in CADAs ith other Computer%AidedB

technologies, CA7 does not eliminate the need for s'illed professionals such

as manufacturing engineers, ;C programmers, or machinists. CA7, in fact,

le!erages #oth the !alue of the most s'illed manufacturing professionals

through ad!anced producti!ity tools, hile #uilding the s'ills of ne

professionals through !isualization, simulation and optimization tools.

References

;arayan, . 6alit ($22). Computer Aided Design and 7anufacturing.

7adsen, Da!id A. ($21$). 9ngineering Draing E Design

Q.No.2: MECHANICA EN!INEER"# "CAE"

7echanical engineersF scales are di!ided into units representing inches to full

size, half size, "uarter size, or eighth size.

To draw an object to a scale of half size, for example, use the mechanical

engineers scale marked half size, which is graduated so that ever

represents !" #n other words, the half-size scale is simpl$ a full-size scale

compressed to half size"
https://en.wikipedia.org/wiki/Machine_toolhttps://en.wikipedia.org/wiki/Manufacturinghttps://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-ota-1https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-ota-1https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-2https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-daintith-3https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-4https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-5https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-ota-1https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-6https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-7https://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttps://en.wikipedia.org/wiki/Computer-aided_designhttps://en.wikipedia.org/wiki/Computer-aided_engineeringhttps://en.wikipedia.org/wiki/Numerical_controlhttps://en.wikipedia.org/wiki/Computer_aided_designhttps://en.wikipedia.org/wiki/Manufacturing_engineerhttps://en.wikipedia.org/wiki/Machinisthttp://books.google.com/books?id=zXdivq93WIUC&printsec=frontcoverhttp://books.google.com/books?id=qdtJDEPZrrkC&pg=PA2https://en.wikipedia.org/wiki/Machine_toolhttps://en.wikipedia.org/wiki/Manufacturinghttps://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-ota-1https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-2https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-daintith-3https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-4https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-5https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-ota-1https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-6https://en.wikipedia.org/wiki/Computer-aided_manufacturing#cite_note-7https://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttps://en.wikipedia.org/wiki/Computer-aided_designhttps://en.wikipedia.org/wiki/Computer-aided_engineeringhttps://en.wikipedia.org/wiki/Numerical_controlhttps://en.wikipedia.org/wiki/Computer_aided_designhttps://en.wikipedia.org/wiki/Manufacturing_engineerhttps://en.wikipedia.org/wiki/Machinisthttp://books.google.com/books?id=zXdivq93WIUC&printsec=frontcoverhttp://books.google.com/books?id=qdtJDEPZrrkC&pg=PA2


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$%ain sca%e8%

A plain scale is used to indicate the distance in a unit and its nest

su#di!ision.

A plain scale consists of a line di!ided into suita#le num#er of e"ual

units. /he rst unit is su#di!ided into smaller parts.

/he zero should #e placed at the end of the 1st main unit.

:rom the zero mar', the units should #e num#ered to the right and the

su#%di!isions to the left.

/he units and the su#di!isions should #e la#eled clearly.

/he =.:. should #e mentioned #elo the scale.

Construct a plain scale of =: G 18, to sho centimeters and long enough tomeasure up to 4 decimeters.

=.:. G H

6ength of the scale G =.:. I ma-. length G H I 4 dm G 1$.4 cm.

Dra a line 1$.4 cm long and di!ide it in to 4 e"ual di!isions, each

representing 1 dm.

7ar' 2 at the end of the rst di!ision and 1, $, and at the end of

each su#se"uent di!ision to its right.

Di!ide the rst di!ision into 12 e"ual su#%di!isions, each representing 1

cm.

7ar' cm to the left of 2 as shon.


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Dra the scale as a rectangle of small idth (a#out mm) instead of

only a line.

Dra the di!ision lines shoing decimeters throughout the idth of the

scale.

Dra thic' and dar' horizontal lines in the middle of all alternate

di!isions and su#%di!isions.

3elo the scale, print D9C&79/9=< on the right hand side,

C9;/&79=/9=< on the left hand side, and =.:. in the middle.

&ernier "ca%e


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6east Count (6C) is the minimum length that can #e measured precisely #y

a gi!en !ernier scale. /his can #e determined #y the folloing e-pression8

6C G 7


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Conic cur!es (conics)

Cur!es formed #y the intersection of a plane ith a right circular cone. e.g.

5ara#ola, hyper#ola and ellipse


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#mportance of %onic &ections

Ohen a plane cuts a cone at right angles to its a-is a circleis formed.

/he a-is passes through the center of the circle, and the focus (and the


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of the cone, the cur!e ne!er cuts the side it is parallel to and as the arms of

the para#ola e-tend into innity they #ecome parallel to each other and the

a-is of the para#ola.


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*)

Q.No.+

Qften, a three dimensional o#ect must #e represented ith precision and

clarity on a plane surface. 5ictorial representations of a three%dimensional

o#ect on a plane are ade"uate only if the o#ect is simple, hoe!er adierent method of representation must #e used for more comple- o#ects K

one that ill sho the true shapes of their surfaces. 3y o#ser!ing the

shados of o#ects cast #y light sources, it can #e seen that an o#ect can #e

RproectedF onto a to%dimensional surface (i.e. a plane of proection) #y

proecting points of the o#ect onto the surface and oining them in order.


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,rtograpic proectionis the graphical method used in modernengineering draing. &n order to interpret and communicate ith engineeringdraings a designer must ha!e a sound understanding of it?s use and a clear!ision of ho the !arious proections are created.

/here are to predominant ortograpic proectionsused today. /hey are #ased on 7onge?s original right angle planes and are shon fully#elo.

/hey dene four separate spaces, or "uadrants. 9ach of these"uadrants could contain the o#ect to #e represented. /raditionally hoe!er,only to are commonly used, the /rst and the tird.

Qrthographic 5roection K Denition Qrthographic proection is a means of

representing a three%dimensional o#ect in to dimensions. &t uses multiple

!ies of an o#ect, from points of !ie rotated a#out the o#ects centre

through increments of 02 degrees. 9"ui!alently, the !ies may #e

considered to #e o#tained #y rotating the o#ect a#out its centre through

increments of 02 degrees. /he !ies are positioned relati!e to each other

according to either of to schemes8 rst%angle or third%angle proection. &n

each% the appearances of !ies may #e thought of as #eing proectedB onto

planes that form a transparent #o-B around the o#ect.


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0irst-ang%e proection

&n /rst-ang%e proection, the o#ect is conceptually located in "uadrant I,i.e. it oats a*oe and *eforethe !ieing planes, the planes are opa3ue,

and each !ie is pusedthrough the o#ect onto the plane furthest from it.

(7nemonic8 an Pactor on a stageP.) 9-tending to the %sided #o-, each !ie

of the o#ect is proected in the direction (sense) of sight of the o#ect, onto

the (opa"ue) interior alls of the #o-+ that is, each !ie of the o#ect is

dran on the opposite side of the #o-. A to%dimensional representation of

the o#ect is then created #y PunfoldingP the #o-, to !ie all of

the interioralls. /his produces to plansand fourele!ations. A simpler

ay to !isualize this is to place the o#ect on top of an upside%don #ol.


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are transparent, and each !ie is pu%%edonto the plane closest to it.

(7nemonic8 a Pshar' in a tan'P, esp. that is sun'en into the Soor.) >sing the

%sided !ieing #o-, each !ie of the o#ect is proected opposite to the

direction (sense) of sight, onto the (transparent) e-terior alls of the #o-+

that is, each !ie of the o#ect is dran on the same side of the #o-. /he #o-is then unfolded to !ie all of its e6terioralls. A simpler ay to !isualize

this is to place the o#ect in the #ottom of a #ol.


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48pes ,f "ections

0u%% "ections

Ohen the cutting plane e-tends entirely through the o#ect in a straight line

and the front half of the o#ect is theoretically remo!ed, a full section is

o#tained, /his type of section is used for #oth detail and assem#ly draings.

Ohen the cutting plane di!ides the o#ect into to identical parts, it is not

necessary to indicate its location. *oe!er, the cutting plane may #e

identied and indicated in the usual manner to increase clarity.


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Ha%f "ections

A symmetrical o#ect or assem#ly may #e dran as a half section,shoing

one half up to the center line in section and the other half in full !ie. Anormal centerline is listed on the section !ie. /he ording, half section, can

#e confusing #ecause one thin's of shoing half the part. =emem#er, a half

section shos one%fourth of the part, not onehalfT

/he half section draing is not normally used here the dimensioning of

internal diameters is re"uired. /his is #ecause many hidden lines ould ha!e

to #e added to the portion shoing the e-ternal features. /his type of section

is used mostly for assem#ly draings here internal and e-ternal features

are clearly shon and only o!erall and center%to%center dimensions are

re"uired.

,9set "ections

&n order to include features that are not in a straight line, the cutting%plane

line may #e oset or #ent, so as to include se!eral planes or cur!ed surfaces,

an oset section is similar to a full section in that the cutting plane e-tends

through the o#ect from one side to the other. /he change in direction of the

cutting%plane line is not shon on the sectional !ie.

ro;en-out "ection

Ohen certain internal and e-ternal features of an o#ect can #e shon

ithout draing another !ie, #ro'en%out and partial sections are used. A

cutting%plane line or a #rea' line is used to indicate here the section is

ta'en. /he #rea' line is normally a agged line, hich #etter indicates the

#rea'. 3ro'en%out sections sa!e draing time and draing space. 7ost CAD

systems ha!e a freehand s'etching tool to create the #rea' line.

A%igned "ection

A aligned section is not a true proection of the cut surface. &t is often used

hen a part contains e#s, ri#s, spo'es, or similar features. &t re!ol!es or

aligns special part features to clarify them or ma'e them easier to represent

in section. Qne can conceptually thin' a#out a aligned section as a

specialized oset section. /he cutting plane can #e #ent to pass through all

of the nonaligned features in the un%sectioned !ie.

Reo%ed "ections


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A re!ol!ed section is made #y re!ol!ing the cross%section !ie 02 degrees

a#out an a-is of re!olution and superimposing the section !ie on the

orthographic !ie. Jisi#le lines adacent to the re!ol!ed !ie can #e either

dran or #ro'en out using con!entional #rea's. Ohen the re!ol!ed !ie is

superimposed on the part, the original lines of the part #ehind the section

are deleted. /he cross section is dran true shape and size, not distorted to

t the !ie. /he a-is of re!olution is shon on the re!ol!ed !ie as a

centerline. =e!ol!ed sections are useful for descri#ing a cross section

ithout ha!ing to dra another !ie. &n addition, these sections are

especially helpful hen a cross section !aries or the shape of the part is not

apparent from the gi!en orthographic !ies.


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Q.No.


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/he line a % # is a true length

/he line c % # is a true length/he line c % d is a true length

/he line a % d is a true length

All other surface areas are not the true length.

Q.No.1?:

4e !%ass o6

Qne ay to understand the standard arrangement of !ies on a sheet of

paper is to en!ision the o#ect in a glass #o-

/he outside o#ser!er ould see si- standard !ies of the o#ect through the

sides of this imaginary glass #o-

!%ass o6 Metod

Ulass 3o- 7ethod8

/he o#ect is placed in a glass #o-.

/he image of the o#ect is proected on the sides of the #o-.

/he #o- is unfolded.


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/he sides of the #o- are the principle !ies.

/he o#ect is placed in a glass #o-.

/he side of the #o- represent the principle planes.


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"i6 $rincip%e &ie5s

*) Mu%ti-ie5: 4e @ principa% ie5s

/he principal !ies are the si- mutually perpendicular !ies that areproduced #y that are produced #y si- mutually perpendicular planes of

proection of proection

&magine an o#ect is sus p g ended in a glass #o-, the sides #ecome

proection plane shoing the si- plane shoing the si- !ies

/he !ies are front, rear, top, , g #ottom, left and ri ght

:ront !ie

Kthe 1st to #e esta#lished

K


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/his forms the #asis of to important multi!ie draing standard

KAlignment of !ies

K:old lines

/op, fron t an d # ottom !ies are all aligned !ertically E share the same

idth dim.

=ear, left, front and right side are aligned horizontally E share same height

dim same height dim.

:old lines are the imaginary hinged edges of the glass #o- .

K/he fold line #eteen the top E front !ies is la#eled *M:

K/he distance from a point in front !ie to the *M: is the same as the

distance from the corresponding point in the top !ie to as the distance from

the corresponding point in the top !ie to the *M: fold line.

eng drawing

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