Transcript CAD Commands - Oban High School

CAD Commands
Technology
Department
Graphic Communication
Aberdeen Grammar School
2D & 3D CAD Commands
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There are a number of common commands
that are used in 2D and 3D CAD packages.
You have to know what these are and what
they do.
The 2D CAD package used in this
presentation is 2D Design.
The 3D software used is Rhino 3D, as used in
industry.
2D CAD Commands - Grids
Orthographic
projection grid
Iso top
Isometric
projection grid
Iso left
Iso right
2D CAD Commands - Grid
Snap
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Grid snap only allows the cursor to
follow the corners of the squares on the
box.
This allows drawings to be produced
quickly and accurately.
2D CAD Commands - Library
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A CAD library allows frequently used symbols like
sockets or doors to be selected from a pre-drawn
catalogue and placed anywhere on the drawing.
This saves the user time and effort.
2D CAD Commands - Layers
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Layers can be used to draw different parts of a
drawing.
For example the room layouts could be drawn on one
layer, the furniture layouts on another and the
electrical fittings on another.
These layers can be viewed all together or one by
one.
It is like drawing these parts on tracing paper and
placing them on top of each other.
This allows the user to view different parts of a
building plan individually to look at parts of particular
interest.
2D CAD Commands - Zoom
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Zooming in allows you to see smaller parts of a
drawing in greater detail.
Zooming out allows you to see the whole of a larger
drawing or can be used after you have zoomed in.
Zooming in
Zooming out
2D CAD Commands - Line Types
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You can draw the different line types
needed for your drawing simply by
selecting the line and selecting a line
type for it.
By clicking on line type a
menu of available lines
appears. You simply select
the type you require.
2D CAD Commands Box/Circle/Arc
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You can draw common shapes quickly
and easily by selecting tools.
You can also choose how you want to
configure these shapes. E.g. in the case
of circle you can drag its size out or set
it by typing in either its diameter or
radius.
2D CAD Commands - Automatic
Dimensioning
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The computer calculates how long a line
is or the diameter of a circle or the
radius of a curve and automatically
places this size on the dimension line.
2D CAD Commands - Copy &
Paste
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You can copy parts of a drawing that
will be repeated and paste these parts
elsewhere.
This is more suitable for either
irregularly spaced copies or 1 copy of
the same shape.
2D CAD Commands - Box
Arrays
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This allows shapes to be repeated in a predetermined
order.
The user chooses how many shapes are to be
repeated along the x-axis and the y-axis.
A box type shape is formed with the repeated parts
hence the name box array.
An example of a box
array with 2 repetitions
along the x-axis and 3
repetitions along y-axis
2D CAD Commands - Ring
Arrays
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This allows shapes to be repeated in a circular
pattern.
The user chooses how many shapes are to be
repeated and the angle at which they are to be
repeated.
The user can also control how many shapes are
to be repeated going out from the centre of the
revolution.
The user must then select the centre point of the
ring array either by clicking on the drawing or
typing a co-ordinate into the ring array
instruction box.
2D CAD Commands - Ring
Arrays
This is an example of
a ring array with the
instruction box shown
alongside.
2D CAD Commands - Fillet
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This is when the user adds a curve to a
corner.
In AutoSketch 6 this command is called
Trim Round.
2D CAD Commands - Chamfer
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This is when the user adds a 45° line to
a corner.
2D CAD Commands - Tangent
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This command allows the user to draw
a line at a tangent to a circle.
This makes this type of line very easy
and quick to produce.
An example of lines
of tangency drawn
between 2 circles.
2D CAD Commands - Break
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This command lets the user delete a
part of a line without having to delete
all of it and redraw what is needed to
be kept.
This is quicker and easier to do than
redrawing a whole line.
Line broken between
these 2 points
2D CAD Commands - Trim
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This allows the user to either extend a
line to meet the edge of another shape
or shorten a line to meet the edge of a
shape.
2D CAD Commands - Trim
We will trim these 2 lines to the
box, one will extend to reach
the edge and one will be
shortened to meet the edge.
Extended line
Shortened line
2D CAD Commands - Extend
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Extending a line is how we make it
longer
Drag the handles on the
ends of the line to make
it longer or shorter.
2D CAD Commands - Rotate
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This allows the user to turn an object around
any angle based on a centre point of rotation.
This box has been rotated
by 45° with its rotation
basepoint the centre of the
rectangle.
2D CAD Commands - Scale
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This command allows the user to say
how much bigger or smaller they want
to make a drawing they have done.
This makes scaled drawings much
quicker and easier to do as a number of
different scales can be produced using
the 1 drawing.
2D CAD Commands - Mirror
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This command gives you a mirror image
of the shape you have drawn.
The user has to set where the mirror
would be placed then the image is
created.
The purple shape has
been mirrored vertically
along the left hand side.
3D CAD Drawing types Wireframe
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These types of drawings only show the
structure of the object drawn.
No other details are shown.
3D CAD Drawing types - Surface
Rendered
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These types of drawings show the
objects as solid shapes.
3D CAD Drawing types - Surface
Rendered
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You can view surface detail as a
rendered block.
It looks realistic due to the highlights
and shading generated by the package.
Some packages like Rhino3D also allow
you to add material to the shape.
This allows high quality drawings to be
produced very quickly.
3D CAD Drawing types - Surface
Rendered
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An Example is shown below.
3D CAD Drawing types - Surface
Rendered
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This allows high quality drawings to be
produced very quickly.
It also means that very realistic models
of a design can be produced without
having to manufacture them, saving
design firms time and money.
3D CAD Drawings
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As all 3D packages use different
commands to produce shapes so you
will not be asked to name any of these
commands in your exam.
You should however, be aware of some
of the things that can be done using
these packages.
3D CAD Drawings
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There are certain things common to all 3D
packages and this is how the shapes are
produced.
You can:
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combine shapes
subtract them from each other
add them together
obtain the orthographic views of the 3D object
using one command.
3D CAD Drawings - Combining
Shapes
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Shapes can be combined.
3D CAD Drawings - Subtracting
Shapes
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Shapes can be subtracted from each
other.
3D CAD Drawings - Adding
Shapes
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You can add shapes to each other.
3D CAD Drawings - Orthographic Views
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You can use one command to obtain
the 3 orthographic views of the object.
Plan
Elevation
End Elevation
3D CAD Drawings
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There are a huge number of other
things you can do with 3D CAD
packages.
It is because of the speed that these
very realistic drawings can be produced
at that design companies have moved
to using these type of drawing
packages.
3D CAD Drawings - Advantages
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An orthographic drawing of an object can be
produced by the software by clicking a
button.
Very realistic objects can be designed very
quickly.
Because these designs are so realistic and
can be made to look like the actual material
they will be made from, clients can see
exactly what is being made so a physical
model is not required, reducing costs and the
time it takes to design a new product.