14. Select Offset, click Remove Highlighted, and click OK.
7. Unconstrained curves after deleting Offset constraint
Multiple Offset Curves: considerations
You can create multiple offsets of a base chain in three ways:
1. Offset the chain using the Number of Copies option.
2. Create independent offsets from the same chain using different Distance values.
3. Create an original offset from the chain, and then create independent offsets from each offset.
Siemens PLM Software encourages you to use options 1 or 2 as appropriate for a given part. However, you should avoid option 3 because:
If you fillet a corner of the base chain, NX cannot propagate the fillet beyond the first offset chain.
Selection Intent does not recognize zero-length curves. If you offset a chain by a distance that produces a zero-length curve, NX may produce unpredictable results for subsequent offsets of the offset chain that contains the zero length curve.
Offset sketch curves: special cases Selection Intent at creation time only
In general, Selection Intent rules apply only when you create an offset. For example, if you offset three connected curves using the Connected Curves Curve Rule, NX does not update the offset if you later add a fourth line coincident to the start or the end of the base chain. Note these common scenarios in which Offset Curve does preserve your design intent when you edit a base chain:
If you fillet a corner in the base chain, NX creates a corresponding fillet in the offset chain (1).
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If you delete a curve in the base chain, NX deletes the corresponding curve in the offset chain (2).
If you extend or trim a curve a curve in the base chain, NX extends or trims the corresponding curve in the offset chain (3).
Note For the three examples above, changes you make to the offset chain do not affect the base chain.
Therefore, trimming or extending an end of an offset chain removes the end constraint.
Middle portion of an offset chain
You cannot trim the middle portion of an offset chain. For example, you cannot trim the portion of the offset chain between the vertical curves below (4). However, you can trim the base chain between the vertical curves (5).
Base curves and zero length
NX will not reduce the base curve of an offset to a length of zero.
For example, this sketch includes a chain offset by 10 mm.
Next, use the Fully Fixed constraint to fix the position of the offset chain.
Edit the offset and reverse the direction so that the base chain is to the inside of the offset chain.
If you edit the offset distance, NX can move only the base chain since the position of the offset chain is fixed. If you increase the distance so that the middle curve in the base chain would go to a zero length, NX returns a conflicting constraint condition.
Offset Curve dialog box Curves to Offset
Select Curve Selects the curve or chain of curves you want to offset. The curve chain can be open, closed, or mixed, and can contain these geometry types:
Lines
Arcs
Circles
Conics
Offset chains
Ellipses
Splines – note that you cannot offset G1 discontinuous curves. For example, if you project a face of a block onto the sketch plane as a single spline, you cannot offset this curve because the input spline has sharp corners.
Note Selection Intent rules apply only when you create an offset. For example, if you
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offset three connected curves using the Connected Curves option, NX does not update the offset if you later add a fourth line coincident to the start or the end of the base chain.
Caution You cannot select more than 200 curves to offset.
Add new set Creates a new sub-chain within the current offset chain. NX displays sub-chains in the List window.
Offset
Distance Specifies the offset distance. Only positive values are valid.
Reverse Direction
Reverses the direction of offset chains. Note that the dialog box button and graphics window direction handles behave differently under certain circumstances.
Clicking reverses the direction of all chains associated with the current operation. For example, if you offset two independent rectangles in one operation, and then click , NX reverses both offset chains.
To flip only one chain, click the corresponding direction handle.
Create Dimension
Creates a Thickness Dimension between the base and offset curve chains.
Deleting this dimension does not delete the offset constraint. To recreate a Thickness Dimension, edit the offset and select the Create Dimension option.
You cannot create a Thickness Dimension from the dimension dialog box.
Note that creating an offset with Create Dimension turned off is not the same as
creating a non-associative offset. Clearing this option creates an associative, but dimensionless, offset.
Symmetric Offset
Creates offset chains on both sides of the base chain. For closed and partially-closed profiles, NX creates an internal chain only if the Distance value is small enough for the chain to fit.
Number of Copies
Specifies how many copies of the offset chain to make. NX offsets each copy from its predecessor by the Distance parameter.
Note The Symmetric Offset and Number of Copies options apply only when you create an offset. NX creates independent offsets tied together only by the dimension expression. For example, creating a symmetric offset is the same as creating two independent offsets from the same base chain in different directions and setting the second expression value equal to the first. If you modify the offset value, note that NX does not update the second offset chain until you click OK.
To make the offsets truly independent, you can break the expression link.
Cap Options Extension Cap – Closes the offset chain by extending curves in their natural direction to a physical intersection point.
Arc Cap – Closes the offset chain by filleting the offset chain curves. The fillet radius is equal to the offset Distance.
Chain Continuity and End Constraints
Show Corners Displays Show Corners handles at each corner in the chain. To open a closed corner, double-click the handle. NX previews the open corner and changes the handle to Close Corner.
1. Open corner handle
2. Close corner handle
3. Output open corner
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Show Ends Displays End Constraint handles at each end of the chain. Double-click the handle to add or remove an End constraint. Note that you can add or remove constraints independently for each copy of an offset chain. To delete the end constraint of an existing offset, right-click the end constraint symbol and choose Delete. Note that this does not delete the offset constraint. It allows you to move the offset end independently of the base.
If the end of an offset has constraints to other curves, NX displays a message. Click OK to remove the existing constraint(s) and add the end constraint.
Settings Convert Input Curves to Reference
Converts the input curves to reference curves. The input curves must reside in the active sketch.
Degree Specifies the degree when you offset a Studio Spline. The default is 3.
Tolerance Specifies the tolerance when you offset a Studio Spline, a conic, or an ellipse. By default, this value matches the Modeling Distance preference in Customer Defaults.
p) Pattern Curve
Use the Pattern Curve command to pattern edges, curves, and points that are parallel to the sketch plane.
The available types are:
Linear Pattern
Circular Pattern
General Pattern
This command also creates a pattern constraint that can be modified when you double-click one of the patterned curves.
Circular Pattern with 5 Instances Where do I find it?
Toolbar
(Modeling) Direct Sketch→Pattern Curve
(Drafting and Sketch task environment) Sketch Tools→Pattern Curve Menu (Modeling and Drafting) Insert→Sketch Curve→Pattern Curve
(Sketch task environment) Insert→Curve from Curves→Pattern Curve
Create an associative pattern of curves
This example shows how to create a pattern of curves in both the X and Y directions.
1.
Double–click a sketch to edit it.
2.
Click Pattern Curve .
3.
Select a curve.
4. Click the middle mouse button to advance.
5.
From the Layout list, select Linear.
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Select the X datum axis to define Direction 1.
7. From the Spacing list, select Count and Pitch.
In the Count box, type 3.
In the Pitch Distance box, type 25.
8.
In the Direction 2 group, select the Use Direction 2 check box.
9.
Select the Y datum axis to define Direction 2.
10. From the Spacing list, select Count and Pitch.
In the Count box, type 2.
In the Pitch Distance box, type 28.
11.
Choose another command or click Apply to create the pattern.
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Create a circular pattern of curves within a boundary
This example shows how to:
Pattern the circle below within the boundaries of the face.
Stagger the pattern.
1.
Double–click a sketch to edit it.
2.
Make sure that Create Inferred Constraints is disabled.
3.
Click Pattern Curve .
4.
Select the circle.
5. Click the middle mouse button to advance.
6. From the Layout list, select Circular.
In the Pattern Definition group, under Boundary Definition, from the Boundary list, select Face.
In the Margin Distance box, type –10.
7.
In the graphics window, select the boundary face.
NX selects the face edges as the boundary.
8. Click the middle mouse button to advance to Specify
Center Point.
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Select the point at the center of the face.
10. In the Angular Direction group:
From the Spacing list, choose Pitch and Span.
From the Define Pitch As list, choose Angle.
In the Pitch Angle box, type 45.
In the Span Angle box, type 360.
11. In the Radial Direction group:
Select the Create Concentric Members check box.
Select the Include First Circle check box.
From the Spacing list, select Count and Pitch.
In the Count box, type 5.
In the Pitch Distance box, type 12.
12.
In the Pattern Settings group, from the Stagger list, select Angle.
NX creates only those pattern instances whose control points lie more than 10 mm from the edge of the face.
13.
To create the pattern, click Apply or choose another command.
Pattern Curve Linear and Circular options
These Pattern Curve options can be associative and edited if you enable Create Inferred Constraints.
Pattern Definition
Linear
Selected curve for pattern.
Direction 1, Count = 3.
Sets the number of objects in the pattern in direction 1.
Pitch Distance
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Sets the distance between each copy of the selected curves.
Span Distance
Sets the distance from the selected curve to the last curve in the pattern.
Direction 2, Count = 2.
Sets the number of objects in the pattern in direction 2.
Circular Selected curve for pattern
Sets the angle from the selected curve to the last curve in the pattern.
Pitch Angle
Sets the angle between each copy of the selected curves.
Span Angle Count = 5.
Sets the number of objects in the pattern.
Create Pitch Expressions Creates expressions for the pattern count and pitch. The expressions are named Pattern_p#.
Pattern Curve General options
These Pattern Curve options can be associative and edited if you enable Create Inferred Constraints.
Pattern Definition General Pattern
Selected curve for pattern.
Selected From Coordinate System From a point or CSYS.
Selected To Coordinate Systems
To a point or coordinate system or many points or coordinate systems.
Orientation = Follow Pattern
Lock Orientation
Locks the rotational angle constraint to follow the original curves. If you do not select the option, you can change the rotation angle of the entire pattern.
Pattern Curve non-associative options
These additional Pattern Curve options only available if you disable Create Inferred Constraints.
These options are useful when you add sketch curves to a drawing.
Pattern Definition Layout list
Polygon — Creates an equilateral polygon, defined by an origin, and the number of sides, and a radial component defined by the object to pattern on the corner.
Number of Sides = 6
Spacing = Count per Side
Count = 4
Span = 360
Spiral — Creates an Along pattern where simplified control of the spiral is provided. The object to pattern will always be at the origin of the spiral. You can specify the distance between the coils, left or right handedness, the total number of turns, and a rotation angle.
Direction = Left Hand
Spiral Size By = Number of Turns
Turns = 2
Radial Pitch = 30
Span = 30
Along – A pattern whose direction is defined by a continuous chain of curves or edges, with instances distributed along the chain according to the spacing parameters.
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Count = 6
Location = % Arc Length
% Pitch Distance = 20
Orientation = Normal to Path
Reference – A pattern based on another pattern. The pattern referenced must be an associative Linear, Circular, or General pattern from the current sketch or another sketch on the same plane.
You can also reference a patterned feature which is two-dimensional and is in a plane parallel to current sketch plane.
Symmetric
Creates symmetric instances of the pattern using the Linear pattern type. This example shows the pattern, in Direction 1 with the Symmetric check box selected.
This example shows the pattern, in Direction 1 and Direction 2 with the Symmetric check box selected.
Boundary Definition
Available for Linear, Circular, Polygon, and Spiral layouts.
Lets you specify a curve or face as a Boundary that will clip pattern instances whose control points reach the boundary, or if they are inside the boundary. You can also specify a Margin Distance that determines how close instances can get to the boundary. A positive margin is to the inside of the boundary, and a negative margin is to the outside of the boundary.
Layout = Linear
Count = 5 and Pitch = 12 in two directions
Boundary = None
Boundary = Face
Margin Distance = 4
All four face edges selected.
Boundary Curve = None
Boundary Curve = Exclude
Circle selected as the boundary. NX clips pattern instances inside the boundary.
Radiate
Available for Circular, and Polygon layouts.
Lets you add concentric members to a pattern, and set the spacing.
Pitch Angle = 45
Span Angle = 360
Create Concentric Members = off
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Create Concentric Members = on
Include First Circle = on
Count = 3
Pitch = 3
Include First Circle = off
Orientation
Available for Circular, Polygon, Spiral, Along, General, and Reference layouts.
Controls whether instances maintain a constant orientation, or follow an orientation based on either the pattern definition or the path.
Layout = Circular
Orientation = Same As Input
Layout = Circular
Orientation = Follow Pattern
Layout = Along
Orientation = Normal to Path
Pattern Increment
Increases or decreases the distance between each pattern instance by the value specified.
Pattern Settings
These options are only available with a linear pattern that has two directions.
Frame Only
Available for Linear layouts. When Frame Only is enabled, NX creates only the outermost instances of a pattern.
Stagger
Available for Linear and Circular layouts. Lets you vary the locations of adjacent rows or columns for a Linear layout, and an angle for a Circular layout. The distance is a preset 1/2 pitch. This example shows a row stagger.
Suppress
Lets you remove any instance(s) in a pattern.
This example shows one instance, on the right side of the pattern, removed with the Suppress option.
Clocking
Lets you offset any instance(s) in a pattern. This example shows one instance, on the right side of the pattern, moved in the X-direction with the Clocking option.
q) Mirror Curve
Use the Mirror Curve command to make a mirrored copy of sketch geometry through a specified sketch line. NX applies mirror geometric constraints to all the geometry.
日 Where do I find it?
Toolbar
(Modeling) Direct Sketch→Mirror Curve
(Drafting and Sketch task environment) Sketch Tools→Mirror Curve Menu (Modeling and Drafting) Insert→Sketch Curve→Mirror Curve
(Sketch task environment) Insert→Curve from Curves→Mirror Curve
Mirror sketch geometry
This example shows how to mirror the top four curves around the bottom line.
1. Double-click any sketch curve to edit the sketch.
2. On the Direct Sketch toolbar, click Mirror Curve . 3. Select the curves to mirror and click the middle mouse button.
4. Select the line to mirror around.