Camd lab manual

TATVA INSTITUTE OF TECHNOLOGICAL STUDIES, MODASA
DEPARTMENT OF MECHANICAL ENGINEERING
T.I.T.S/D.E/MECH./C.A.M.D/3RD SEM/LAB MANUAL Page 1
PRACTICAL: 1
AIM:- To study about Basic Knowledge of Computer.
Introduction:-
A computer system consists of mainly four basic units; namely input
unit, storage unit, central processing unit and output unit. Central Processing unit
further includes Arithmetic logic unit and control unit, as shown in the figure:. A
computer performs five major operations or functions irrespective of its size and
make. These are
• it accepts data or instructions as input,
• it stores data and instruction
• it processes data as per the instructions,
• it controls all operations inside a computer, and
• it gives results in the form of output.
Functional Units:
a. Input Unit: This unit is used for entering data and programs into the computer
system by the user for processing.
b. Storage Unit: The storage unit is used for storing data and instructions before
and after processing.

c. Output Unit: The output unit is used for storing the result as output produced
by the computer after processing.
d. Processing: The task of performing operations like arithmetic and logical
operations is called processing. The Central Processing Unit (CPU) takes data and
instructions from the storage unit and makes all sorts of calculations based on the
instructions given and the type of data provided. It is then sent back to the storage
unit. CPU includes Arithmetic logic unit (ALU) and control unit (CU).

• Arithmetic Logic Unit: All calculations and comparisons, based on the
instructions provided, are carried out within the ALU. It performs arithmetic
functions like addition, subtraction, multiplication, division and also logical
operations like greater than, less than and equal to etc.
• Control Unit: Controlling of all operations like input, processing and output are
performed by control unit. It takes care of step by step processing of all operations
in side the computer.

Memory
Computer‟s memory can be classified into two types;
 primary memory and
 secondary memory
a. Primary Memory can be further classified as RAM and ROM.
RAM
• RAM or Random Access Memory is the unit in a computer system. It is the place
in a computer where the operating system, application programs and the data in
current use are kept temporarily so that they can be accessed by the computer‟s
processor. It is said to be „volatile‟ since its contents are accessible only as long as
the computer is on. The contents of RAM are no more available once the computer
is turned off.
ROM or Read Only Memory is a special type of memory which can only be read
and contents of which are not lost even when the computer is switched off. It
typically contains manufacturer‟s instructions. Among other things, ROM also
stores an initial program called the „bootstrap loader‟ whose function is to start the
operation of computer system once the power is turned on.
b. Secondary Memory.
RAM is volatile memory having a limited storage capacity. Secondary/auxiliary
memory is storage other than the RAM. These include devices that are peripheral
and are connected and controlled by the computer to enable permanent storage of
programs and data.

 CD ROM
Secondary storage devices are of two types; magnetic and optical. Magnetic
devices include hard disks and optical storage devices are CDs, DVDs, Pen drive,
Zip drive etc.
• Hard Disk
Hard disks are made up of rigid material and are usually a stack of metal disks
sealed in a box. The hard disk and the hard disk drive exist together as a unit and is
a permanent part of the computer where data and programs are saved. These disks
have storage capacities ranging from 1GB to 80 GB and more. Hard disks are
rewritable.

• Compact Disk
Compact Disk (CD) is portable disk having data storage capacity between 650-700
MB. It can hold large amount of information such as music, full-motion videos,
and text etc. CDs can be either read only or read write type.
• Digital Video Disk
Digital Video Disk (DVD) is similar to a CD but has larger storage capacity and
enormous clarity. Depending upon the disk type it can store several Gigabytes of
data. DVDs are primarily used to store music or movies and can be played back on
your television or the computer too. These are not rewritable.
Input / Output Devices:
These devices are used to enter information and instructions into a computer for
storage or processing and to deliver the processed data to a user. Input/Output
devices are required for users to communicate with the computer. In simple terms,
input devices bring information INTO the computer and output devices bring
information OUT of a computer system. These input/output devices are also known
as peripherals since they surround the CPU and memory of a computer system.
Input Devices
An input device is any device that provides input to a computer. There are many
input devices, but the two most common ones are a keyboard and mouse. Every
key you press on the keyboard and every movement or click you make with the
mouse sends a specific input signal to the computer.
• Keyboard: The keyboard is very much like a standard typewriter keyboard with
a few additional keys. The basic QWERTY layout of characters is maintained to

make it easy to use the system. The additional keys are included to perform certain
special functions. These are known as function keys that vary in number from
keyboard to keyboard.
• Mouse: A device that controls the movement of the cursor or pointer on a display
screen. A mouse is a small object you can roll along a hard and flat surface. Its
name is derived from its shape, which looks a bit like a mouse. As you move the
mouse, the pointer on the display screen moves in the same direction.
• Trackball: A trackball is an input device used to enter motion data into
computers or other electronic devices. It serves the same purpose as a mouse, but is
designed with a moveable ball on the top, which can be rolled in any direction.

• Touchpad: A touch pad is a device for pointing (controlling input positioning) on
a computer display screen. It is an alternative to the mouse. Originally incorporated
in laptop computers, touch pads are also being made for use with desktop
computers. A touch pad works by sensing the user‟s finger movement and
downward pressure. • Touch Screen: It allows the user to operate/make selections
by simply touching the display screen. A display screen that is sensitive to the
touch of a finger or stylus. Widely used on ATM machines, retail point-of-sale
terminals, car navigation systems, medical monitors and industrial
control panels.
• Light Pen: Light pen is an input device that utilizes a light-sensitive detector to
select objects on a display screen.

• Magnetic ink character recognition (MICR): MICR can identify character
printed with a special ink that contains particles of magnetic material. This device
particularly finds applications in banking industry.
• Optical mark recognition (OMR): Optical mark recognition, also called mark
sense reader is a technology where an OMR device senses the presence or absence
of a mark, such as pencil mark. OMR is widely used in tests such as aptitude test.
• Bar code reader: Bar-code readers are photoelectric scanners that read the bar
codes or vertical zebra strips marks, printed on product containers. These devices
are generally used in super markets, bookshops etc.
Scanner:Scanner is an input device that can read text or illustration printed on
paper and translates the information into a form that the computer can use.
A scanner works by digitizing an image.

Output Devices:
Output device receives information from the CPU and presents it to the user in the
desired from. The processed data, stored in the memory of the computer is sent to
the output unit, which then converts it into a form that can be understood by the
user. The output is usually produced in one of the two ways – on the display
device, or on paper (hard copy).
•Monitor: is often used synonymously with “computer screen” or “display.”
Monitor is an output device that resembles the television screen (fig. 1.8). It may
use a Cathode Ray Tube (CRT) to display information. The monitor is associated
with a keyboard for manual input of characters and displays the information as it is
keyed in. It also displays the program or application output. Like the television,
monitors are also available in different sizes.
• Printer: Printers are used to produce paper (commonly known as hard copy)
output. Based on the technology used, they can be classified as Impact or Non-
impact printers.
Impact printers use the typewriting printing mechanism wherein a hammer strikes
the paper through a ribbon in order to produce output. Dot-matrix and Character
printers fall under this category.
Non-impact printers do not touch the paper while printing. They use chemical, heat
or electrical signals to etch the symbols on paper. Inkjet, Deskjet, Laser, Thermal
printers fall under this category of printers.

• Plotter: Plotters are used to print graphical output on paper. It interprets
computer commands and makes line drawings on paper using multi colored
automated pens. It is capable of producing graphs, drawings, charts, maps etc.
• Facsimile (FAX): Facsimile machine, a device that can send or receive pictures
and text over a telephone line. Fax machines work by digitizing an image.

PRACTICAL: 2
AIM:-To Study Of AutoCAD and AutoCAD Commands.
Introduction:-
AutoCAD is general purpose computer aided design and drafting
programming which can prepare wide variety of 2D drawings and 3D drawings or
models. The created drawing data file which can be retrieved at any time for
drawing editing and plotting. It is powerful drawing tool that can be highly
customizing a special application. It improves productivity of creating drawing
because of increasing speed and accuracy as compared to traditional methods. The
software of AutoCAD came this market in December 1982 and it was released in
1988.
SELECTING COMMANDS IN AUTOCAD :-
AutoCAD provided the different method to:
a. Enter or select command
b. Key board
c. Pull-down menu
d. Icon menu
A. HELP:-
Command: - Help[F1]
Function: To obtain a list of AutoCAD Command.
B. LIMITS:-
Command: - limit (on/off) < lower left corner > < current valve>
Function: - to designate to drawing boundaries for the current
drawing and control to checking of those limits.
C. POINT:-
Command: - point
Function: - to draw a point it can be used as mark or sharp point.
D. LINE:-
Command; line (L)
specify first point;
specify next point; or (undo)
specify next point or (close/undo)
E. CIRCLE:-
Command: - circle (c)
Specify center point of circle or (3p/2p/TTR)
Specify radios at circle.
Function: - it is use to draw a circle with the specify center and radios.

F. ARC:-
Command; arc (a)
Centre/ start point, Centre/ end/ < second point > angle/ length of
Chord/ <end point > A include angle.
Function: - To draw arc with different methods like:-
Three points
Start, Centre, end
Start, Centre, included angle
Start, Centre, length of chord
Start, end, starting direction
Start, end, radius
Line/arc condition
G. POLYGON:-
Command: Polygon [PO]
Number of sides : <edge/centre of polygon > inscribed circle/circle
inscribed about circle [I/C] :- Radius at centre
Function:- To Draw Polygon with edge or inscribed in circle or with
inscribed about circle.
H. ELLIPSE:-
Commands: - Ellipse [el]
Arc/Centre <axis end point> : arc end point rotation/< other
axis
Distance> rotation around rear axis.
Function: - To draw ellipse with methods like end distance centre
distance, End rotation and centre rotation.
I. ERASE:-
Commands: - Erase [e]
Function: To remove unwanted objects from drawing permanently.
J. MOVE:-
Command: - Move [m]
Select object base point or displacement second point of
Displacement.
Function: - To move one or more entities from their present location to
new One without changing their orientation or size.
K. ROTATE:-
Command: - Rotate [Ro]
Select object: Base point : <rotation angle>/reference
angle<o>[value]new angle <value>.

Function: -To change the orientation of existing entities by rotating
them About a specified base point.
L. SCALE:-
Commands: - scale [sc]
Select object: - Base Point: [scale factor] reference:- reference length
[l]: New length
Function: -To change the size of existing.
M. MIRROR:-
Commands: - Mirror [Mi]
Select Object: [items to be missed]
First point of mirror line, second point: - Deleted old objects :-[M]
Function: - To make mirror images at existing object in drawings
N. STRETCH:-
Command: - Stretch [S].
Select object to stretch try window.
Select objects.
Base point.
New point.
Function: - To move a selected portion of a drawing presenting
connections to parts 68 the drawing in place.
O. ARRAY:-
Command: - Array [Ar]
Selected portion of a drawing preserving connections to ports .
Functions: To make multi-copies of selected object in a rectangular /
polar pattern.
P. BREAK:-
Command: - Array [Ar].
Select object: [specify object to be broken] enter second pint.
Function: - to erase port at a line type from circle are on 2d polyline.
Q. TRIM:-
Command: Trim [Tr]
Select within edge.
Select object.
Function: - To trim some objects so they and precisely of a coating
other objects.
R. EXTENDS:-
Command: - Extends [ex]
Select boundary edge.

Select Object.
Function: - To lengthen existing objects so they and precisely at
boundary edge defined by object.
S. FILLET:-
Command: - Fillet [f].
Polyline / Radius/ trim / select two objects> [point to two
objects]
Function: - To connect two line are or circle by meant of a smoothly
filled one of a specified radios .
T. CHAMFER:-
Command: - Chamfer [che].
Polyline / distance /<elect first line >:- [point to one line].select
second liner :- [point to inter selected line ].
Function: - To trine interesting line in a specified distance from the
inter setting and connect the trimmed ends with a new line segment.
U. OFFSET:-
Command: offset [o]
offset distance of through [last]: select object to offset. Slide to
offset to through point.
Function: to construct an entity parallel to another entity at either a
specified distance or through a specified point.
V. DIVIDE:-
Command: divide [div]
Function: to divide entity into several entity at either a specified
distance or through a specified point.
W. MEASURE:-
Command: measure [me]
select object to measure <segment length>/ block
Function : to measurement an entity placing
X. ZOOM :-
Command: zoom[z].
all/center/dynamic/extend/left/previous/window/<scale>
Function: to increase or areas the apparent size of items being viewed
in the current view. Part all through their actual size remain constant.
Y. PAN:-
Command: pan [p]
displacement second point .
Function: to view a lift portion of the drawing in the current view without
changing the magnification.

Z. VIEW:-
Command: view? /delete/restore/save/window:[select one] view name:
[name]
Function : to save current view parts to restore it later.
AA. LAYER:
Command: layer [la].
?/make/set/new/on/off/color/types/freeze through select:
Function: to create a new layer select the line type for designated layers,
torn layers on and off. Just the defined.
AB. COLOUR:
Command: colour [col] New entity colour [c current>]
Function: to set the current for sub sequently drawn entities.
AC. LINE TYPE:
Command: Line type /create load/ set:
Function: - To set the current for subsequently drawn entities.
AD. LINE TYPE SCALE:-
Command: - LTS New scale factor.
Function: - To set the current elevation and extra action thickness for
sub-sequent entities being draw. To change the scale factor for
drawing to derivation.
AE. PEDIT :-
Command:- pedit [Pe]
Select polyline [one/two/many] entity selected is not a
polyline.
Do you want to turn into one? [Y]
Close/join/width/edit vertex/find/spline/decurve/undo/exit.
Function :- It is used for editing spline.
AF. TAB SURF :-
Command:-Tab Surf
Select Path curve.
Function: - To contract a polygon mesh approximately a tabulated
surface by moving of specified direction vector along select path.
AG. REV SURF:-
Command: - rev surf.
Select path curve, select axis of revolution: start angle [0] [<w=<w]
Included angle [f= [w]]< full circle]
Function: To construct a polygon mesh. Approximately a constant
surface path Sounded by four edges of object selected.

AH. EDGE SURFACE:-
Command: edge surface
Select 1, select 2
Function: - To construct a polygon mesh approximately a cones surface
path bounded by four edge object selected.
AI. 3D MESH GENERAL POLYGON MESH:-
Command: - 3D mesh
Mesh M size [integer valve], mesh N size [integer value],
vertex (m,n) [value]
M code, N code very form 2 to 256.
Function: - To construct a general polygon mesh vertex by vertex.
AJ. UCS:-
Command: - UCS
Origin / Z-axis/ 3 point entity view/ x/y/z/ prev. / restore/ save / del/?
[word]
Function: - To define UCS
AK. UCS ICON:-
Command: - UCS icon
On /off/ all/ on origin/ origin <current> on/ off state
Function: - To change from one UCS to another.

PRACTICAL NO: 3
AIM : To Study of 3D Modeling Using Auto CAD.
Introduction:
To work in three dimensions in AutoCAD, we need to use a third
axis on the rectangular
(Cartesian coordinate system. This axis (defined as Z), determines the depth
of an object. In this context, the X-axis will identify the WIDTH, the Y-axis
LENGTH and the Z-axis
determines the DEPTH of an object.
1. Start a new file from scratch. Accept all the default settings.
2.
2. Turn the Grid and Snap ON (F7 & F9), and use the default spacing.
Command: grid <Enter>
Specify grid spacing(X) or
[ON/OFF/Snap/Major/aDaptive/Limits/Follow/Aspect]
<0.5000>: L <Enter>
Display grid beyond Limits [Yes/No] <Yes>: n <Enter>
Command: <Enter>

<0.5000>: d <Enter>
Turn adaptive behavior on [Yes/No] <Yes>: n <Enter>
Command: <Enter>
GRID
<0.5000>: .5 <Enter>
{Press F7 to turn the grid ON}
Command: <Grid on>
Command: z <Enter>
ZOOM
Specify corner of window, enter a scale factor (nX or nXP), or
[All/Center/Dynamic/Extents/Previous/Scale/Window] <real time>: a
<Enter>
3.Create a new layer named object, assign the color green to it, and
make it the current layer.
4. Enter the ELEV Command and set the new default elevation at 1”
and the new
default thickness at 3”.
Command: elev <Enter>
Specify new default elevation <0.0000>: 1 <Enter>
Specify new default thickness <0.0000>: 3 <Enter>
5. Begin you drawing with the LINE Command, and construct the figure
1.Do not be concern about the exact sizes. Keep your drawing proportional
to one
shown in Figure 1.
6. Use the VPOINT and set it to SE Isometric.
Command: vpoint <Enter>
Current view direction: VIEWDIR=0.0000,0.0000,1.0000

Specify a view point or [Rotate] <display compass and tripod>: 1,-1,1
<Enter>
Regenerating model.
You may access this command from “View” pull down menu.
(Figure 2)
Your drawing in SE Isometric will look similar to one shown in figure 3
7. Changing the Elevation and Thickness
Command: elev <Enter>
Specify new default elevation <1.0000>: -1 <Enter>
Specify new default thickness <3.0000>: 6 <Enter>

PLAN VIEW 3D View
8. Add a circle as shown on Figure 4 and view from SE Isometric.
8. From the “View” Pull Down menu ,select “Hide”, or enter the HIDE
command from the keyboard.

Creating Primitives BOX
Start a new file from scratch. Accept all the default settings.
1. Use the VPOINT and set it to SE Isometric.
2. Use the pull-down menu or the
toolbar to select the desired command. You may also type in command
line.
Command: vpoint <Enter>

Current view direction: VIEWDIR=0.0000,0.0000,1.0000 <Enter>
Specify a view point or [Rotate] <display compass and tripod>: 1,-1,1
<Enter>
Regenerating model.
Command: box <Enter>
Specify first corner or [Center]: {Pick a point anywhere on screen}
Specify other corner or [Cube/Length]: L <Enter>
Specify length: 4 <Enter>
Specify width: 3 <Enter>
Specify height or [2Point]: 2 <Enter>
Figure

PRACTICAL: 4
AIM:-To Study of 2D parametric drawings.
Introduction:-
Geometry in parametric drawing is constrained with a set of mathematical
and geometrical rules with respect to other geometries of the drawing. A parametric
approach to design offers a big list of advantages over classical non-parametric
design approach.
Consider a scenario where you have completed designing a part having
complex geometry. Suddenly you realize that something needs to be changed in the
drawing. Making that change will affect your complete design, and with each
change you need to update its dependent component geometry manually.
That‟s a tedious enough job by itself, but what if the same issue happens with
an assembly drawing? You get the point; it will be a nightmare to update every part
and then the overall assembly to ensure changes are properly reflected everywhere!
It‟s also clearly apparent that this task will be error prone and it will cost you
extra design hours.
Now, if the design is made with a parametric approach, then a design change
will automatically update any dependent geometry, eliminating the chances for
human error and, best of all, saving you lots of design editing time.
Parametric Feature in AutoCAD
The parametric constraint feature was added to AutoCAD 2010, making
drawing with AutoCAD much more efficient. With AutoCAD you can apply
geometric and dimensional constraints to your drawing, and with the parameters
manager you can also add formulas to your drawing. These formulas can be used
to define relationships between different parts of the geometry.
I will explain the usage of parametric features on a sample 2D drawing. I
will demonstrate it using both geometric and dimensional constraints, and also how
to use the parameters manager for adding formulas to dimensional constraints.
Applying Geometric Constraint
Let‟s take, for example, this geometry where we have a circle inside a
polygon in such a way that the circle is tangent to both the non-parallel sides of the

polygon. This geometry is completely unconstrained and changing the length of
any side of the polygon or radius of the circle will break the tangency in the
geometry.
Circle tangent to opposite non-parallel side of a polygon. (All images
courtesy of the author.)
To ensure that the relationship between the circle and the non-parallel
lines is maintained, I will apply a tangent geometric constraint between them.
Select the Parametric tab from AutoCAD‟s drafting and annotation workspace and
click on Tangent Constraint from the Geometric panel. Next click on circle, then
on bottom horizontal line. A new tangent constraint will be added between the
objects and a box containing an icon of tangential constraint will appear near the
point of tangency. Repeat the process of applying a tangential constraint between
the circle and top inclined line of the geometry.
Now the circle is constrained with respect to both lines but the polygon
itself is not constrained. A change in the circle geometry will force the polygon to
change.
In order to constrain the polygon, start with the Fix geometric constraint
and click on the left endpoint of the bottom horizontal line. This will ensure that
polygon‟s bottom left point will remain fixed in space. To ensure that the bottom
line remains horizontal, select Horizontal constraint and click on the bottom
horizontal line of polygon.
To ensure that both vertical lines of the polygon remain perpendicular to the
bottom horizontal line we need to apply a perpendicular constraint. Select
Perpendicular from the Geometric panel and click on the left vertical line of
polygon and then on the bottom horizontal line. Repeat the process with the right
vertical line as well.

Now that all the relevant geometric constraints are in place, we need to
apply dimensional constraints to make the drawing fully constrained.
Applying Dimensional Constraint
As the name suggests, dimensional constraints will restrict dimensions of
geometry to a specified value.When that value is subsequently changed, the
geometry will also update itself to match.
Select Linear from Dimensional panel and now click on bottom horizontal
line of polygon near left end, then click at right end of line and place the constraint
at a convenient location. Repeat the process for both vertical lines of the polygon
as well.
Now the geometry is almost completely constrained except for the circle in
the middle; the radius of the circle is still not fixed and it can be changed. To
constrain the radius of circle select Radius from Dimensional Constraints panel and
click on circle, then place the parameter at a suitable point.

Using Formulas to Manipulate Geometry
Using formulas, the relationship between different parts of the geometry can be
established in such a way that if the geometry changes, it does so in a controlled
manner with respect to the formulas defined.
Let‟s define some formulas so that all dimensional parameters of the drawing will
be controlled with the radius of circle. Click on Parameters Manager on the
Manage panel of the Parametric tab. Alternatively, you can also use the
PARAMETERS command. Once the command is active, you will see a palette as
shown below:
Parameters manager displaying all currently defined dimensional constraints.
You will see a list of all dimensional constraints used in the drawing.
Double click in the blank area under the last constraint and a new user parameter
will be added with default name user1. Change the name of the parameter to A by
double clicking on its name. Now double click in front of parameter A under
expressions column and enter this expression: ((rad1*2)+1)/2.
This expression will define value of parameter A with respect to the value of
rad1. Similarly, add one more user parameter, give it name B and enter expression
(rad1^2)+1.

Then create a third user parameter, C, and assign an expression B*2. This
expression will ensure that the value of parameter C will directly depend on
parameter B, which is in turn is dependent on the value of rad1.
Now our drawing is ready for accepting user parameter values. Now go to
the dimensional constraints in the Parameters Manager palette and double-click on
the d1 constraint in the expression column and change its value to C. Similarly,
change the value of d2 to A and d3 to B. After making all these changes, this is
how parameters manager palette will look:
User-defined dimensional parameters using formulas.
Now all of the dimensions of geometry are directly dependent on the value
of rad1 parameter.
You will notice an fx symbol before the name of every dimensional
constraint on the drawing. This symbol appears when a dimensional constraint
references one or more user parameters. These constrains appear only in the
drawing area; they will not appear in your plot. The fx symbol facilitates
recognition of parameter-dependent constraints to avoid accidental changes of
these values or to understand situations where you might over-constrain the
geometry.

To test our drawing, change the value of the rad1 parameter by double
clicking on it and assign a value 3 to it. You will notice that complete geometry
changes according to the defined formulas or expressions of Parameters Manager
palette.
Conclusion
The parametric drawing feature of AutoCAD makes your drawing changes very
efficient and fast. For a beginner it might be little confusing, but with practice this
feature will add much value to your drawing.
With this feature, design change becomes a very seamless task and it also
minimizes chances of making mathematical errors while doing manipulations. If
you have not yet tried this feature, I recommend you give it a shot. I am sure you
will not be disappointed with the results.

PRACTICAL: 5
AIM:-To Study of Orthographic projection.
Introduction:-
Orthographic projection (or orthogonal projection) is a means of
representing a three-dimensional object in two dimensions. It is a form of parallel
projection, where all the projection lines are orthogonal to the projection
plane,resulting in every plane of the scene appearing in affine transformation on
the viewing surface. A lens providing an orthographic projection is known as an
(object-space) telecentric lens.
The term orthographic is also sometimes reserved specifically for depictions
of objects where the axis or plane of the object is also parallel with the projection
plane, as in multiview orthographic projections.
Origin
The orthographic projection has been known since antiquity, with its
cartographic uses being well documented. Hipparchus used the projection in the
2nd century BC to determine the places of star-rise and star-set. In about 14 BC,
Roman engineer Marcus Vitruvius Pollio used the projection to construct sundials
and to compute sun positions.
Vitruvius also seems to have devised the term orthographic (from the Greek
orthos (= “straight”) and graphē (= “drawing”) for the projection. However, the
name analemma, which also meant a sundial showing latitude and longitude, was
the common name until François d'Aguilon of Antwerp promoted its present name
in 1613.
The earliest surviving maps on the projection appear as woodcut drawings of
terrestrial globes of 1509 (anonymous), 1533 and 1551 (Johannes Schöner), and
1524 and 1551 (Apian).
Multiview orthographic projections
Multiview orthographic projection With multiview orthographic
projections, up to six pictures of an object are produced, with each projection plane
parallel to one of the coordinate axes of the object. The views are positioned
relative to each other according to either of two schemes: first-angle or third-angle
projection. In each, the appearances of views may be thought of as being projected

onto planes that form a 6-sided box around the object. Although six different sides
can be drawn, usually three views of a drawing give enough information to make a
3D object. These views are known as front view, top view and end view.

PRACTICAL: 6
AIM:-To Study of Assembly Drawings.
Introduction:-
 Definitions :
 What is an assembly drawing and why do we need them?

An assembly drawing is a drawing of an entire machine .
We need to know how to put the machine together.
Subassembly Drawing
Subassembly: Two or more parts that form a portion of an assembly.
Can you think of some examples of subassemblies?
 A car differential
 A motorbike engine
 A compressor in an AC
Working Drawing Package
Working Drawing Package: A packet of drawings that gives the specifications
necessary to manufacture a design.
A typical working drawing package includes;
 an assembly drawing,
 detailed drawings,
 and a standard parts sheet.
 A standard part sheet contains information about purchased items and will
not be discussed in this course.
Drawing Order:
Drawings included in a working drawing package should be presented in the
following order.
 Assembly drawing (first sheet)
 Part Number 1
 Part Number 2
 ....
 Standard parts sheet (last sheet)
Views Used in Assembly Drawings
Selecting Views:
 Does an assembly drawing need a FRONT, TOP and RIGHT SIDE view?
 Sometimes
 We need as many views as it takes to identify and locate each part.
 It may only take one view.

Sectional Views
Sectional views are used quite often when drawing assemblies.
Why?
Assemblies often have parts fitting into or overlapping other parts and we need to
look inside the assembly to see clearly.

Exercise: 1
 Draw Following Orthographic Figures & Give Dimensions.
Figure: 1
Figure: 2

Figure:3
Figure:4

Exercise: 2
 Draw Following Isometrics Figures & Give Dimensions.
Figure: 1
Figure: 2

Figure: 3
Figure: 4

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