AutoCAD 2010 Training

Parametric Constraints

 

Aims and Objectives

The aim of this tutorial is to provide you a basic understanding of parametric modeling and work with geometric and dimensional constraints, should be able to:

 

Geometric Constraints

Start a new drawing from scratch. Use Metric defaults. Then use the Lines and Circle command to construct a T-shaped geometric. See Figure 2.

Using Startup system variable to control display of  New Drawing dialog box when a new drawing is started with NEW or QNEW.

Command: STARTUP
Enter new value for STARTUP <0>: 1

Using menubar system variable to control display of menu bar.

Command: MENUBAR
Enter new value for MENUBAR <0>: 1

<File> <New...>

Command: NEW
[Create New Drawing
Start from Scratch
Metric
OK ]

Figure 1  New Drawing

<Modeling panel> <Lines>
<Modeling panel> <Circle><Center, Radius>

Figure 2  Sketch

 

 

Figure 3  Geometric constraint- Coincident


 

 

 

 

 

 

 

 


 


Figure 4
  Coincident points

<Parametric tab><Geometric panel>  <Coincident>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Coincident
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint A (Figure 4)]
Select second point or [Object] <Object>:
[Select Endpoint B (Figure 4)]

 

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint C (Figure 4)]
Select second point or [Object] <Object>:
[Select Endpoint D (Figure 4)]

 

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint E (Figure 4)]
Select second point or [Object] <Object>:
[Select Endpoint F (Figure 4)]

 

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint G (Figure 4)]
Select second point or [Object] <Object>:
[Select Endpoint H (Figure 4)]

 


 

 

 

 

 

 

 

 

 

 

Figure 5  Coincident points

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint A (Figure 5)]
Select second point or [Object] <Object>:
[Select Endpoint B (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint C (Figure 5)]
Select second point or [Object] <Object>:
[Select Endpoint D (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint E (Figure 5)]
Select second point or [Object] <Object>:
[Select Endpoint F (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint G (Figure 5)]
Select second point or [Object] <Object>:
[Select Endpoint H (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint K (Figure 5)]
Select second point or [Object] <Object>:
[Select Midpoint J (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Endpoint L (Figure 5)]
Select second point or [Object] <Object>:
[Select Midpoint M (Figure 5)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first point or [Object/Autoconstrain] <Object>:[Select Midpoint O (Figure 5)]
Select second point or [Object] <Object>:
[Select CenterPoint N (Figure 5)]

 


Figure 6  parallel constraint

 


Figure 7
  Sketch

<Parametric tab><Geometric panel>  <Parallel>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Parallel
Select first Object:[Select  A (Figure 7)]
Select second Object:
[Select Endpoint B (Figure 7)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select first Object :[Select C (Figure 7)]
Select second Object :
[Select F (Figure 7)]


Figure 8  Collinear constraint

<Parametric tab><Geometric panel>  <Collinear>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_COLinear

Select first Object :[Select E (Figure 7)]
Select second Object :
[Select D (Figure 7)]


Figure 9  Horizontal constraint


Figure 10 Sketch

<Parametric tab><Geometric panel>  <Horizontal>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Horizontal

Select an object or [2Points] :[Select C (Figure 10)]
 


Figure 11 Vertical constraint

<Parametric tab><Geometric panel>  <Vertical>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Vertical

Select an object or [2Points] :[Select A (Figure 10)]

Press [Enter] key to repeat last command.

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:
[Enter]
Select an object or [2Points] :[Select B (Figure 10)]


Figure 12 Equal constraint


Figure 13 Sketch

<Parametric tab><Geometric panel>  <Equal>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Equal

Select first object or [Multiple] :M
Select first object :[Select A (Figure 13)]
Select object to make equal to first :[Select B (Figure 13)]
Select object to make equal to first :[Select C (Figure 13)]
Select object to make equal to first :[Enter]


Figure 14 Perpendicular constraint


Figure 15 Sketch

<Parametric tab><Geometric panel>  <Equal>

Command: _GeomConstraint
Enter constraint type
[Horizontal/Vertical/Perpendicular/PArallel/Tangent/SMooth/Coincident/CONcentric
/COLlinear/Symmetric/Equal/Fix] <Coincident>:_Perpendicular

Select first object :[Select A (Figure 15)]
Select second Object :[Select B (Figure 15)]

Dimensional Constraints



Figure 16 Sketch


Figure 17 Dimensional Constraint

<Parametric tab><Dimensional panel>  <Aligned>

Command: DIMCONSTRAINT
Current settings: Constraint form = Dynamic
Select associative dimension to convert or
[LInear/Horizontal/Vertical/Aligned/ANgular/Radial/Diameter/Form] <Aligned>:_Aligned
Specify first constraint point or [Object/Point & line/2Lines] <Object>:
[Enter]
Select object:
[Select A (figure 16)]
Specify dimension line location:
[Select B (figure 16)]
Type L1=25

Press [Enter] key to repeat last command.

Command: DIMCONSTRAINT
Current settings: Constraint form = Dynamic
Select associative dimension to convert or
[LInear/Horizontal/Vertical/Aligned/ANgular/Radial/Diameter/Form] <Aligned>:
[Enter]
Specify first constraint point or [Object/Point & line/2Lines] <Object>:
[Enter]
Select object:
[Select C (figure 16)]
Specify dimension line location:
[Select D (figure 16)]
Type L1/2
[Enter]


Figure 18 Vertical constraint

<Parametric tab><Dimensional panel>  <Vertical>

Command: _DimConstraint
Current settings: Constraint form = Dynamic
Select associative dimension to convert or
[LInear/Horizontal/Vertical/Aligned/ANgular/Radial/Diameter/Form]
<Diameter>:_Vertical
Specify first constraint point or [Object] <Object>:
[Select CenterPoint H (figure 16)]
Specify second constraint point:
[Select Endpoint F (figure 16)]
Specify dimension line location:
[Select K (figure 16)]
Type
 =L1
[Enter]


Figure 19 Angular constraint

<Parametric tab><Dimensional panel>  <Angular>

Command: _DimConstraint
Current settings: Constraint form = Dynamic
Select associative dimension to convert or
[LInear/Horizontal/Vertical/Aligned/ANgular/Radial/Diameter/Form]
<Aligned>:_Angular
Select first line or arc or [3Point] <3Point>:
[Select E (figure 16)]
Select second line:
[Select F (figure 16)]
Specify dimension line location:
[Select G (figure 16)]
Type 70
[Enter]

 


Figure 20 Diameter constraint

<Parametric tab><Dimensional panel>  <Diameter>

Command: _DimConstraint
Current settings: Constraint form = Dynamic
Select associative dimension to convert or
[LInear/Horizontal/Vertical/Aligned/ANgular/Radial/Diameter/Form]
<Aligned>:_Diameter
Select arc or circle:
[Select H (figure 16)]
[Select G (figure 16)]

Enter a new value : L1/3
[Enter]

To turn off the display of all constrain, select [Show Dynamic Constraints].


Figure 21 Show dynamic constraints

Double-click the constraint to change its value.


Figure 22 Sketch

[Double-click constraints  A (figure 22)]
Enter a new value : 50
[Enter]

<File> <Save>
File name: Para.dwg

Key Points

You can use this tools to control the shape, size and dimensions of your design.

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