Computer Aided Draughting 415
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d:\N-Design\Des21-1.pm5
21.12.2 To Draw Cone
Cone offers several methods for drawing a 3D solid cone. The default is to choose a centre point,
then pick or enter the diameter/radius and apex.
Command: CONE
1. Elliptical / <0, 0, 0): pick a centre point or enter E
2. Diameter / : provide a diameter or radius
3. Apex /: provide the apex or height
Options:
Centre — allows to create a cone with a circular base.
Elliptical — allows to create a cone with an elliptical base.
Centre of other end — allows to specify top end of the cone.
Height — allows to specify the height of the cone.
21.12.3 To Draw a Box
The box command creates a 3D solid box.
Command: BOX
1. Centre/ <0, 0, 0>: pick up the first corner point for the box
2. Cube/length/ : pick up a second corner point or enter a value
3. : provide the box height by picking two points or entering a value
Options:
Centre — allows to create a 3D box using a specified centre point.
Cube — allows to create a 3D box with all sides equal.
Length — allows to enter values for length, width and height.
21.13 CREATION OF COMPOSITE SOLIDS
Complex solids can be created from both solid primitives and swept solids. Boolean operations
can be used to create composite solids from two or more solids. Solid modelling is a built-in
facility with AutoCAD 14, which provides for region and solid modelling. Region models are two
dimensional closed areas consisting of lines, polylines, arcs, circles and ellipses. From these,
mass properties and surface areas can be assessed. Solid models are true shape 3D objects.
The region command allows creating 2D enclosed areas from existing overlapping closed
shapes (loops).
21.13.1 To Create Regions
Command: REGION
1. Select objects: select objects to be combined into a region
2. Press: ↵
A composite region may be created by subtracting, combining or finding the intersection
of regions.
To create composite regions (Fig. 21.17a, b):
Command: Union, Subtract and Intersect
1. Select objects: select the regions to be combined into a composite region
2. Press ↵ to end the command
