NX8 DOCUMENTATION
SKETCHING
2011
drive24ward MESLAB 11/5/2011日
Sketching
Browse Categories
Sketch tutorials Sketch basics
Creating and managing sketches
Creating and editing geometry Creating dimensions
Creating constraints
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What are you looking for in Sketching? Sketch overview
Customizing the Sketch task environment
Sketch menus quick reference Sketch video examples
1. What are you looking for in Sketching?
How do I?
> **Unsatisfied xref title**
> Quickly create a model with Direct Sketch > Sketch on a plane
> Sketch on a path > Reattach a sketch
> Fully constrain an ellipse
> Exit a sketch without saving changes
Learn more about > Direct sketching
> Direct Sketch and the Sketch task environment > Continuous Auto Dimensioning
> Sketching in an assembly context > Constraint tips
2. Sketch overview
A Sketch is a named set of 2D curves and points located on a specified plane or path. You can apply rules, in the form of geometric and dimensional constraints, to establish the criteria your design needs. Features created from a sketch are associated with it; if the sketch changes so do the features.
You can use sketches to create:
The profile or typical sections of your design.
Detailed part features by sweeping, extruding, or revolving a sketch into a solid or a sheet body. Large-scale 2D concept layouts with hundreds, or even thousands, of sketch curves.
Construction geometry, such as a path of motion, or a clearance arc, that is not meant to define a part feature.
Sketch Constraints
In a sketch you can fully capture your design intent through geometric and dimensional relationships as
constraints. Use constraints to create parameter-driven designs that you can update easily and predictably.
NX evaluates constraints as you work to ensure that they are complete and do not conflict. While it is not required, Siemens PLM Software recommends that you fully constrain sketches that define feature profiles.
A sketch also offers you the flexibility to create as many, or as few, constraints as your design requires. That means you can use a sketch to create wireframe drawings that can serve a wide variety of up-front design purposes, and are not meant for down-stream processing. For example you might create 2D layout sketches for products such as digital cameras, printers, or other devices in which you focus on:
Product structure Component layout Basic component shape
Or you might create construction geometry including: Area/volume restrictions in a part
Range/arc of free motion Part labels or logos Layout of grille holes
Sketches like these typically require few, if any, constraints. Sketch in Place/Sketch on Path
When you create a sketch, you can define its plane and orientation using one of two methods: Sketch in Place
Sketch on an existing planar face, or on a new or existing sketch plane. Key considerations that will guide your selection are:
Does the sketch define the base feature for the part? If so, create the sketch on an appropriate datum plane or datum coordinate system.
Is the sketch adding to an existing base feature? If so, select an existing datum plane or part face, or create a new datum plane with an appropriate relationship to existing datum planes or part geometry.
Sketch on Path
This is a specialized type of constrained sketch that you use to create a profile for a Variational Sweep feature. You can also use Sketch on Path to position a sketch for features like Extrude and Revolve. For all commands, you select the target path and define a sketch plane location on that path.
Note that you can use the Reattach command to easily switch a sketch from the Sketch in Place method to Sketch on Path.
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3. Sketch tutorials
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Create a sketch and solid model quickly
Sketch on a planar face
Create tongue and groove type parts
Create a dome-shaped part Create a base support
a) Create a sketch and solid model quickly
This tutorial shows you how to:
Create and extrude a sketch profile. Fully constrain the sketch.
Edit the sketch directly.
1.
Click New
2. Create a new Millimeters part based on the
Model template. Enter profile as the part name. When you click OK, NX automatically starts the Modeling application.
3.
4.
Select the Point of the Datum Coordinate System.
5.
Move your mouse to the right.
When you see a dashed help line with an arrow, click a screen position where the line is approximately 40mm long.
A horizontal line is created.
6.
Move your mouse above the line.
When you see a dashed help line with an arrow, click a screen position where the line is approximately 30mm long.
A vertical line is created.
7.
Click a screen position where the line is approximately 30mm long.
日 8.
Move your mouse to the left above the coordinate system.
When you see a dotted help line, click a screen position.
The line end point is normal to the dotted help line.
9.
Select the Point of the Datum Coordinate System.
10. While the Direct Sketch toolbar is still active,
click Extrude
The sketch is fully constrained with automatic
dimensions.
11. Choose another command or click the middle
mouse button to create the extrusion and finish the sketch.
12.
Double–click the sketch to edit it.
13.
Click Inferred Dimensions . 14.
Select the vertical line.
15.
Click to place the dimension.
16.
日
Note:
The 30mm automatic dimensional constraint was replaced by the driving dimensional constraint.
The model updated as soon as you changed the sketch because you are editing the sketch directly.
The sketch is still fully constrained. 17.
Click Finish Sketch .
b) Sketch on a planar face
This tutorial shows you how to create a sketch on a planar face and how to dynamically:
Select the Sketch:
o Plane
o Orientation
o Origin
Switch between Profile line mode and arc mode.
1.
Click Profile . 2.
Click the face to define the sketch plane, orientation, and origin.
As you move the cursor over the planar face, the sketch origin point is previewed at the nearest end point to which it will be constrained.
3.
Make sure Create Inferred Constraints is selected.
4.
Move your mouse to the right. When you see a dashed help line with an arrow, click a position on the face to create a horizontal line.
5.
Drag to the right of the line to switch from line to arc creation mode.
6.
Move your mouse above the line. When you see a dotted help line to the center point of the arc, click. This will create a 180 degree arc that is tangent to the horizontal line.
7.
Move your mouse to the left parallel to the first line. When you see a dotted help line, click to create a horizontal line.
日 8.
Drag to the left of the line to switch from line to arc creation mode.
9.
Select the end point of the first line to complete the profile.
10. While the Direct Sketch toolbar is still active,
click Extrude . 11.
In the End on-screen input box, type 5. You may need to click Reverse Direction to extrude the sketch into the solid.
12. Choose another command or click the middle
mouse button to create the extrusion and finish the sketch.
c) Create tongue and groove type parts
This tutorial shows you how to sketch on a path and use the Variational Sweep command to create a part with a tongue. You could use the same principles to create the mating part with a groove. The mold for the tongue would be cut by a fixed-axis ball nose end mill with 2 degree draft.
1. Click here to download the part.
Click Open . Open on_path.prt.
日 2.
Choose Insert→Sketch in Task Environment .
3.
From the Type list, select On Path .
4. From the Curve Rule list, select Tangent
Curves. 5.
Select one of the edges to define the path.
All the top edges highlight because you chose the Tangent Curves Curve Rule. This allows the sketch profile to follow the entire edge.
6.
This orients the sketch plane to match the normal front view of this part.
7. In the Plane Orientation group, from the
Orientation list, select Parallel to Vector . In the Sketch Orientation group, from the Method list, select Automatic.
The plane orientation vector matches the machine tool axis that would mill the shape created by the variational sweep at the end of this tutorial. 8.
Select the Datum Axis.
9. Click the middle mouse button to accept the path.
10. Make sure Continuous Auto Dimensioning
is turned off.
Click Inferred Constraints and Dimensions .
11.
Clear all the constraint check boxes except Coincident and Midpoint, and click OK.
日 12.
Use the Profile and the Line commands to create the curves.
Make sure the centerline is created between the midpoints of the two horizontal lines.
13.
Choose Insert→Curve from
Curves→Intersection Point .
14. On the Selection toolbar, from the Curve Rule
list, select Tangent Curves. 15.
Select one of the bottom edges.
All the bottom edges highlight because you chose the Tangent Curves Curve Rule. This allows the point to follow the entire edge.
16.
Click Line . 17.
Select the bottom Intersection Point.
18.
Select the Vertex of Datum On Path. Press Esc to exit the Line command.
This line will always be parallel to the outside face of the solid. It is also parallel to the tool axis. All constraints will reference this line so that the tongue is a machinable feature.
19.
Right-click the line and choose Convert to Reference.
20.
日 21.
Select the two lines shown.
One for the Primary Object and the other for the Secondary Object.
22.
Make sure the Make Reference check box is selected.
23.
Select the middle line for the Symmetry Centerline.
24.
Make sure Show All Constraints is selected.
25.
Click Constraints . 26.
27.
Select Datum Axis (5).
28.
Right-click the datum axis and choose Parallel .
29.
Select the centerline and the base line. Right-click one of the lines and choose
Perpendicular .
30.
Select the centerline and the top line. Right-click one of the lines and choose
日 31.
Choose Insert→Datum/Point→Point . 32.
Click a screen position inside the profile to create a point on the sketch plane.
This point is used to keep the sketch centerline positioned at the desired vertical distance from the top face of the part.
33.
Click Constraints . 34.
Select the point and the sketch datum axis. Right-click the sketch datum axis and choose
Point On Curve .
35.
Select the point and the centerline.
Right-click the centerline and choose Point On
Curve .
36.
37.
Select the two lines.
38.
Click to place the dimension. Type 2 in the on-screen input box. Press Enter.
39.
From the Dimensions Drop-down list , select Perpendicular Dimension . 40.
Select the base line.
Hold the cursor over the point until it changes to the QuickPick cursor, then click.
日 41.
Click to place the dimension. Type 1 in the on-screen input box. Press Enter.
42.
Select the top line.
Hold the cursor over the point until it changes to the QuickPick 1 cursor, then click.
In the OuickPick dialog box, select Point.
43.
Click to place the dimension.
Type 1.5 in the on-screen input box. Press Enter.
44.
Select the center line.
Select the reference line along the face of the solid.
45.
Click to place the dimension. Type 2 in the on-screen input box. Press Enter.
46.
From the Dimensions Drop-down list , select Parallel Dimension .
47.
Select the top line.
48.
Click to place the dimension. Type 2 in the on-screen input box. Press Enter.
The status line says: Sketch is fully constrained.
49. Click Inferred Constraints and Dimensions
. 50.
日 51.
Click Fillet. . 52.
Click Trim.
Make sure Delete Third Curve is not selected. 53.
Select the first curve to fillet.
54.
Select the second curve to fillet.
55.
Select the top line.
This line defines the tangency as well as the fillet radius.
56.
Right-click the top line and choose Convert to Reference.
57. Right-click in the background of the graphics
window and choose Finish Sketch . 58.
Choose Insert→Sweep→Variational Sweep .
59.
日
The sweep path was defined when you selected
the sketch path.
60.
From the Boolean list, select Unite .
61. Click the middle mouse button to create the
sweep.
d) Create a dome-shaped part
This tutorial shows you how to create a dome-shaped part with a notch. You can use a Sketch on Path and the Variational Sweep command to construct the part.
1. Click here to download the part.
Click Open . Open dome.prt. 2.
Click Insert→Sweep→Variational Sweep.
3.
In the Section group, click Sketch Section .
4. Define the sketch plane:
Click anywhere on the lower spline. In the Plane Orientation group, from the
Orientation list, choose Through Axis .
In the Plane Orientation group, click
Specify Vector .
Select the Z-axis of the Datum CSYS. In the Sketch Orientation group, from the
Method list, select Use Curve Parameters. To create the sketch, click the middle mouse
button. 5.
Make sure Continuous Auto Dimensioning is disabled.
6.
Create an intersection point on the upper spline: From the Offset Curve drop-down list,
choose Intersection Point . Select the upper spline.
NX creates a point where the spline intersects the sketch plane.
日 7.
Create the line:
On the Sketch Tools toolbar, click Line .
Select the upper Intersection Point. Select the Vertex of Datum On Path.
8.
Create the arc:
Click Arc .
Click the Arc by Center and Endpoints method.
Click as shown to create the arc center point and end points.
9. Constrain the arc center to the Z-axis:
Click Constraints .
Select the arc center and the Z-axis of the Datum CSYS.
Right-click the datum axis and choose Point
10.
Constrain the right end of the arc to the Z-axis: Select the right end of the arc.
Select the datum axis.
Right-click the datum axis and choose Point
on Curve .
11.
Create the notch:
On the Sketch Tools toolbar, click Profile .
Select the Point on Curve Snap Point option.
Construct a vertical line and horizontal line similar to the lines shown.
12.
Create the dimensions that will control the sweep:
Click Inferred Dimensions .
Select the two line ends as shown and place the dimension.
Type 4.1 in the on-screen input box and press Enter.
日 13.
Select the two line ends as shown and place the dimension.
Type 8.0 in the on-screen input box and press Enter.
14.
Select the Normal datum axis of the sketch CSYS and the end of the arc and place the dimension.
Type 33.1 in the on-screen input box and press Enter.
15. Right-click in the graphics window and choose
Finish Sketch.
16. From the Curve Rule list, choose Connected
Curves.
From the Selection bar, choose Stop at Intersection .
17.
Select the sketch geometry that you want to sweep, being sure to define the notch correctly.
e) Create a base support
This tutorial shows you how to create a base support using fully-constrained loops.
1.
Click New
2. Create a new Millimeters part based on the
Model template.
Enter base support as the part name.
日 3. Click Profile . 4.
Click a screen position to the left and below the CSYS to define the first point of the profile and the sketch: Plane Orientation Origin 5.
Click Show All Constraints and ensure that Create Inferred Constraints.
Click Show All Constraints
Ensure that Create Inferred Constraints is active.
Click Inferred Constraints and Dimensions , select all the Constraints to Infer and Apply check boxes, and click OK.
6.
Draw a 100 mm horizontal line from left to right below the XC axis.
7.
Drag to the right of the line to switch from line to arc creation mode.
8.
Move your mouse above the line.
When you see a dotted help line to the center point of the arc, click.
This will create a 180 degree arc that is tangent to the horizontal line.
9.
Continue drawing the sketch until it looks like a closed loop with two arcs at either end.
10.
Click Constraints .
日 11.
Select the two arcs.
12.
Right-click on an arc and choose Equal Radius .
13.
Select the two lines.
14.
Right-click on a line and choose Equal Length
15.
If the lines are not horizontal select them, right-click on a line and choose Horizontal .
16.
Select the bottom line near its middle, and then select the Point of the Datum Coordinate System.
日 17.
Right-click on the point and choose Midpoint .
18.
Select either arc near its center, and then select the Datum Axis.
19.
Right-click in the datum axis and choose Point
On Curve .
20.
21.
Select the top and bottom lines.
Place the dimension to the left of the part. In the on-screen input box, type 125 and press Enter.
22.
Select both arcs.
Place the dimension below the part.
In the on-screen input box, type, type 225 and press Enter.
The status line says: Sketch is fully constrained.
23.
Click Offset Curve . 24.
From the Curve Rule list, select Connected Curves.
25.
In the Offset group, select Create Dimension check box, and clear the Symmetric Offset check box.
26.
Select any curve in the profile.
In the Distance on-screen input box, type 14 and press Enter.
If necessary, double–click the direction vector to reverse the offset direction toward the inside of the original profile.
日 27.
Click Apply to create the loop.
28.
Use the same steps to create two additional inner loops at offsets 30 mm and 40 mm.
29.
The first offset loop provides reference geometry to position counterbored holes.
Select all the curves in the loop.
Right–click the loop, and choose Convert To Reference.
30. To position counterbored holes, add points at
each end of the reference arcs .
31.
Select the ends of each reference arc to create 4 Points.
32.
You need to create two more points to position two more counterbored holes.
Place a point on the midpoint of each arc.
33.
Right-click in the background of the graphics window and choose Finish Sketch .
34.
Click Extrude
From the Curve Rule list, select Connected Curves.
日 35.
Select the outermost loop.
In the End on-screen input box, type 20 and press Enter.
If necessary, double–click the direction vector to reverse the extrude direction downward.
Click Apply.
36.
Select the first loop inside of the reference loop. In the End on-screen input box, type 60 and press Enter.
If necessary, double–click the direction vector to reverse the extrude direction upward.
37. In the Boolean group, from the Boolean list,
Inferred should be the default selection. The status line says: Boolean will be Unite, because you are extruding away from the existing solid.
Click Apply. 38.
If necessary, switch to wireframe display. Select inner most loop.
Click the sphere that represent the Start Distance In the Start on-screen input box, type 36 and press Enter.
39.
In the Boolean group, from the Boolean list, select Subtract.
40.
Click Hole
41. In the Form and Dimensions group, from the
Form list, choose Counterbored. In the Dimensions sub-group type:
C-Bore Diameter = 15
C-Bore Depth = 3
Diameter = 10
Depth Limit list→Through Body
42.
Select one of sketch reference curves.
NX places a counterbored hole at each sketch point.
43.
Click the middle mouse button to create the holes.
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4. Sketch basics
View a topic
Direct Sketch and the Sketch task environment The sketch process
Sketch On Plane and Sketch On Path Sketching in an assembly context Internal and External sketches Open a sketch for edit
Make a sketch internal or external Sketches and Layers
Sketch curve dynamic preview Sketch help lines
Sketch on-screen input boxes Copy, move, and edit sketch objects Types of constraints
Controlling the display of constraints Lock inferred constraints
Constraint tips
Degree-of-freedom arrows Short List
Viewing and editing multiple sketch expressions
a) Direct Sketch and the Sketch task environment
The Direct Sketch toolbar and the Sketch task environment offer two modes you can use to create and edit sketches. Siemens PLM Software recommends that you:
Use the Direct Sketch toolbar when you want to:
Create or edit a sketch in the Modeling, Shape Studio, or Sheet Metal applications. See the effect of sketch changes on the model in real-time.
Edit an internal sketch.
Experiment with sketch changes, but retain the option to discard all the changes. Create a sketch in other applications.
b) The sketch process
Typical steps involved in creating sketches: 1. Select a sketch plane or path.
2. Choose your constraint recognition and creation options.
3. Create the sketch geometry. Depending on your settings, the sketch creates many constraints automatically.
4. Add, modify, or delete constraints.
5. Modify dimension parameters to meet your design intent. 6. Finish the sketch.
c) Sketch On Plane and Sketch On Path
Sketch On Plane
Create a Sketch On Plane when you want to associate the sketch feature to a planar object such as a datum plane or a face.
1. Sketch on the plane of a Datum CSYS 2. Sketch on a face of the extruded sketch.
Sketch On Path
Create a Sketch On Path when you are building an input profile for features like Variational Sweep. This example shows a fully constrained Sketch On Path and the resulting variational sweep.
日 1. Path 2. Sketch
3. Variational Sweep
d) Sketching in an assembly context
You can create and edit sketches while working in the context of an assembly.
The Selection Scope (1) and Create Interpart Link (2) options on the Selection bar help you work with sketches in the context of an assembly.
Use the Selection Scope option to indicate the selection range you want. You can select objects from the Entire Assembly, from Within Work Part Only, or from Within Work Part and Components if it is a subassembly.
When you want to create a permanent associative link for the selection, turn on the Create Interpart Link option before you make a selection.
These options are only available for commands that support these functions.
Selecting the sketch placement face
You can select the placement face for the sketch from any part in the assembly using the Selection Scope option Entire Assembly. You can also optionally create an associative interpart link to the selected sketch face using the Create Interpart Link option.
When selecting the horizontal or vertical reference for the sketch orientation, the Entire Assembly option is not available. You can select this reference only from within the work part. You can however, select this reference from any edge of the placement face even if it is from another part in the assembly, because a copy of this face is created in the work part.
Using geometry from other parts
Some sketch commands allow you to select geometry from any component in the assembly, and some allow you to create associative interpart links.
For example, when using the Profile, Line, Arc, Circle, or Derived Lines sketch commands, use the Selection Scope option Entire Assembly when you want the sketch to snap to existing geometry on other parts in the assembly. With these commands, the Create Interpart Link option is not available and permanent constraints are not created.
Constraining sketches to other parts
If you want to create permanent associative constraints between sketch curves and other geometry in the assembly, first project the desired edges or points into the sketch using one of the commands Project Curve, Intersection Point, or Intersection Curve. The Create Interpart Link option is available in these commands to create associative links. You can create normal sketch constraints between the projected objects and other sketch curves.
For example, to constrain a circle in your sketch to align with an edge from another part in the assembly, first project the edge into the sketch using the Create Interpart Link option, then constrain the circle to the projected curve.
Editing sketches in an assembly context
Sketches are created as a feature in the work part of the assembly. This can be the top-level assembly or any component (part or subassembly).
You can only edit existing sketches when the part that contains it is the work part. If you are in a sketch, and want to edit a different sketch in your assembly, exit the sketch, and make the part that contains the sketch you want to edit the work part. You cannot change the current work part in the sketch.
日
make sure that the desired sketch is included in the reference set used in the assembly and that it is on a visible layer.
e) Internal and External sketches
Sketches that you create from within commands like Variational Sweep, Extrude, or Revolve are
internal sketches. Use an internal sketch when you want to associate the sketch with only one feature.
Sketches you create independently using the Sketch command are external sketches, and are visible and accessible from anywhere within a part. Use an external sketch to keep the sketch visible and make it available for use in more than one feature.
Differences between Internal and External sketches
Internal sketches are accessible only from the owning feature.
External sketches are accessible from the Part Navigator and the graphics window.
You cannot use an internal sketch with any feature other than its owner unless you externalize the sketch. Once you make a sketch external, the former owner has no control over the sketch.
f) Open a sketch for edit
Only one sketch can be active at a time. While a sketch is active, NX adds any geometry you create to that sketch. How you activate a sketch depends on whether the sketch is internal or external.
Internal Sketches
In the Part Navigator, right-click the owning feature and choose Edit Sketch.
In the Part Navigator or the graphics window, double-click the owning feature. On the feature dialog box, click the Sketch Section step to activate the Sketch task environment.
External Sketches
From Modeling you can open external sketches in a number of ways, depending on your work preference: Double-click a sketch curve in the graphics window.
From the Part Navigator:
o Double-click a sketch feature.
o Right-click a sketch and choose Edit. Choose Edit→Sketch.
Edit Multiple Sketches
You can edit multiple sketches when you require just one model update. To edit multiple sketches you must:
Choose Insert →Sketch task environment . Select a sketch name from the Sketch toolbar.
To edit subsequent sketches, you can double-click a sketch in the Part Navigator or select another sketch name from the Sketch toolbar.
g) Make a sketch internal or external
Consider this example of a Variational Sweep that is based on an internal sketch.
i) To externalize the internal sketch, right–click the Variational Sweep in the Part Navigator and choose Make Sketch External.
NX places the sketch before its former owner in Timestamp order.
SKETCH_000 now appears before the Variational Sweep. Datum Coordinate System (0) Spline (1) Spline (2) Spline (3) Sketch (4) ‖SKETCH_000‖ Variational Sweep (5) ii) To reverse this operation, right–click the former owner and choose Make Sketch Internal.
When you internalize SKETCH_000, it no longer appears in the Part Navigator.
Datum Coordinate System (0) Spline (1) Spline (2) Spline (3) Variational Sweep (4)
iii) To edit the internal sketch, do one of the following:
o Right-click Variational Sweep in the Part Navigator and choose Edit Sketch.
o Double-click Variational Sweep and, in the Variational Sweep dialog box, click Sketch Section.
h) Sketches and Layers
You can Hide and Show sketches from the Part Navigator. You do not need to put each sketch on a different layer to control its visibility.
When you open a sketch, the layer that the sketch resides on becomes the work layer.
When you exit a sketch, the layer settings depend on whether you selected the Maintain Layer Status check box in the Preferences→Sketch→Session Settings dialog box.
o If you select the check box, the sketch layer and work layer are returned to the status they had before you activated the sketch.
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i) Sketch curve dynamic preview
As you create curves, a dynamic preview of the curve displays with related possible constraints and alignment indicators. This display shows what the object looks like if you click at the current cursor position.
Preview of an Arc
Until you click the point that completely defines the curve, values in the on-screen input boxes update as you move the cursor.
j) Sketch help lines
Help lines indicate alignment to control points of curves, including line endpoints and midpoints, arc endpoints, and arc and circle centerpoints. Two types of help lines can display during curve creation:
A dotted help line indicates alignment with other objects.
A dashed help line indicates an inferred constraint with other objects, such as horizontal, vertical, perpendicular and tangent.
1. Dotted help line aligned with midpoint. 2. Dashed help line with vertical constraint.
k) Sketch on-screen input boxes
On-screen input boxes accept XC/YC values or object parameter values. Depending on the type of curve you create, one or more on-screen input boxes display in the graphics window and move with the cursor. Two sets of boxes can display for the Profile, Line, Arc, and Circle commands:
XC 23.85 YC 48.65
Object Parameter values that are specific to the type of curve. Here is an example of the Line input parameters.
Length 0.05 Angle 12.09
The first column displays the name of a parameter and the second column contains parameter values. To move between on-screen input boxes, press Tab or Enter. To specify a value, type it in the appropriate box and press Enter.
Clearing Input Box Values
To clear a value, double-click the box and press Backspace. Locking and Unlocking Values
You can lock the parameter value of an on-screen input box. For example, to lock the XC-coordinate value, enter a value and press Tab. The XC value updates with the locked value. As you move the cursor, the YC value continuously updates to reflect the cursor position.
To unlock a value, clear the on-screen input box. Smart Rounding
For a description of smart rounding and its dependency on the view scale, click here.
l) Copy, move, and edit sketch objects
To Do This
Move curves, points, or dimensions Drag the curves, points, or dimensions Move curves or points vertically or horizontally with
snapping Hold Shift and drag the curves or points
Move curves or points vertically or horizontally without
snapping Hold Shift+Alt and drag the curves or points
Copy curves or points Hold Ctrl and drag the curves or points
Copy curves or points vertically or horizontally with snapping
Hold Ctrl+Shift and drag the curves or points
Copy curves or points vertically or horizontally without snapping
Hold Ctrl+Shift+Alt and drag the curves or points
日
Edit objects Double–click the objects
Choose a command Right–click the objects
Note If you are in another command that requires a selection, you must exit the command before you perform these actions. To exit a command, press Esc.
m) Types of constraints
Use constraints to precisely control the objects in a sketch and to express the design intent for a feature. There are two types of constraints: geometric constraints and dimensional constraints.
Geometric Constraints
A geometric constraint establishes a relationship between two or more sketch objects, for example, requiring that two lines be perpendicular or parallel, or that several arcs have the same radius.
1. Tangent 2. Vertical 3. Horizontal 4. Offset 5. Perpendicular 6. Coincident Dimensional Constraints
Dimensional constraints, also called driving dimensions, establish
The size of a sketch object such as the radius of an arc or length of a curve. A relationship between two objects, such as the distance between two points.
Dimensional constraints display like drafting dimensions in that they have dimension text, extension lines, and arrows. However, dimensional constraints dictate the size of sketch objects.
n) Controlling the display of constraints
Unless Show No Constraints is enabled, the software always displays these constraints:
Coincident
Point on Curve
Midpoint
Tangent
Concentric
You can control the display of other constraints with the Show All Constraints and Show No Constraints commands.
By default, constraints do not display if the associated geometry is very small. To see all constraints, clear the Dynamic Constraint Display option under Preferences→Sketch→Session Settings.
o) Lock inferred constraints
You can lock inferred constraints when you see a preview of a curve direction. This option is particularly useful when complex sketch geometry makes it difficult to pick the location you want AND retain the desired constraints.
日
Constraint symbols display in the graphics window as you move the cursor. When you see an inferred constraint, you can lock that constraint by clicking the middle mouse button. For example, if you lock in a perpendicular constraint, the curve previews only in a perpendicular direction as you move the cursor.
To unlock the constraint, click the middle mouse button again.
Use the Inferred Constraints and Dimensions command to control the types of constraints that NX infers.
p) Constraint tips
Although you do not need to fully constrain a sketch to use it for downstream feature creation, the best practice is to fully constrain sketches. A fully constrained sketch ensures that a solution can be
consistently found during design change. Note the following tips on how to constrain a sketch and what to do when a sketch is over constrained:
You can use a combination of Automatic and Driving Dimensions, and Constraints to fully constrain a sketch.
Whenever you encounter an overconstrained or a conflicting constraint status, you should resolve the situation immediately by deleting some dimensions or constraints.
Perpendicular, Horizontal, and Vertical dimensions maintain their direction when the expression value is set to zero. You can also enter negative values for these three dimension types to achieve the same results as using the Alternate Solution command. Avoid zero dimensions for other dimension types. Using zero dimensions leads to problems with ambiguous relative positioning to other curves. This can cause unexpected results when changing the dimension back to a nonzero value.
Use lines rather than linear splines to model linear sketch segments. Although they appear to be the same geometrically, lines and linear splines behave differently during sketch evaluation. You can also use reference curves to assist in constraining objects. You create reference curves
from sketch curves with the Convert To/From Reference command.
q) Degree-of-freedom arrows
Degree-of-freedom (DOF) arrows mark points on a sketch that are free to move. There are three types of degree-of-freedom: positional, rotational, and radial. This example shows positional constraints:
1. This point is free to move in the X direction only.
2. This point is free to move in the Y direction only.
3. This point is free to move in both the X and Y directions.
When you constrain a point from moving in a given direction, NX removes the DOF arrow. Applying one constraint can remove several DOF arrows. When all the arrows are gone, the sketch is fully constrained. Fully constrain a sketch when you need complete control of the design. Note that constraining a sketch is optional. You can use an under-constrained sketch to define a feature.
r) Short List
NX maintains a memory of five objects called the short list to check for inferred constraints. NX uses the short list to avoid testing against every curve in the current sketch when inferring constraints. Curves are added to the list as you create them or when you pass your cursor over a curve.
When NX infers a constraint between an object on the short list and the curve being created, the short list object highlights and you see a preview of the constraint.
Tip The short list is structured from top to bottom. When curves are created or passed over with the cursor, they are placed on top of the short list. When the list is full, the curve at the bottom is removed before adding a new curve at the top.
日 NX clears the short list when you leave a curve command.
s) Viewing and editing multiple sketch expressions
You can view and edit multiple sketch expressions in either of the following ways:
Use the Sketch Parameters command to edit or delete expressions for driving dimensions in the current sketch.
Use the Expression tool to create and edit expressions anywhere in the current part. NX updates the entire model whenever you change an expression. Expression changes you make while Sketching will cause downstream features to update according to the current configuration of the sketch.
Where do I find it?
Menu (Modeling, Drafting, and Sketch task environment) Edit→Sketch Parameters (Modeling, Drafting, and Sketch task environment) Tools→Expression
5. Creating and managing sketches
View a topic
Direct sketching
Create and Reattach Sketch Sketch groups
Orient View to Sketch Orient View to Model Delaying Sketch updates Delay Evaluation
Evaluate Sketch Update Model
Replace with Independent Sketch Rename a sketch
Finish Sketch Exit Sketch
a) Direct sketching
A Direct Sketch toolbar is available in Modeling. Use the commands on this toolbar to create a sketch on a plane without entering the Sketch task environment.
When you create a point or curve using the commands on this toolbar, a sketch is created and is active. The new sketch is listed in the model history in the Part Navigator. The first point you specify defines the sketch plane, orientation, and origin.
You can define the first point on the following: Screen position
Curve Face Plane Edge
Specified Plane
Specified Datum CSYS Why should I use it?
Direct sketching requires fewer mouse clicks, which makes creating and editing sketches faster and easier. Where do I find it?
Application Modeling, Shape Studio, Sheet Metal Toolbar Direct Sketch
Create a sketch directly in Modeling
This example shows how to create a sketch using the Direct Sketch toolbar with a part containing a Datum CSYS. You create two rectangles, trim them to each other, and finally extrude the sketch.
1.
Click Rectangle .
2.
Click above the X-Axis and to the right of the Y-Axis.
3.
For the second rectangle point, select the Datum CSYS point.
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The sketch is dimensioned and fully constrained.
4. Optional step:
If the sketch was not automatically dimensioned, Continuous Auto Dimensioning is turned off by the customer default setting. Turn on Continuous Auto
Dimension .
5.
While Rectangle is still selected, click the first point for the next rectangle inside the first rectangle.
6.
Click the second rectangle point.
7.
Select Quick Trim.
8.
Drag your mouse over the curves to trim them.
The first curve is trimmed.
The second curve is trimmed.
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The fourth curve is deleted.
9. While the Direct Sketch toolbar is still active,
select Extrude.
Note
If Finish Sketch is available, the sketch is
active.
The active sketch is selected.
10.
Enter the limit values. For this example, 140 is entered for the End Distance.
11. Click the middle mouse button to create the extrusion.
Direct sketch and feature edit preferences
Set the following in the Modeling Preferences dialog box for the actions available when you double-click sketches and features.
Edit tab
Edit Sketch Action
Direct Edit
Lets you edit the sketch directly in Modeling.
Caution Direct Edit updates the model immediately. Select Task Environment if you have sketches with many dependent features.
Task Environment
Enters the Sketch task environment.
Double-click Action (Sketches)
Edit with Rollback
Makes the selected sketch the current feature and enters the Sketch task environment.
Edit
Enters the sketch without changing the current feature.
Double-click Action (Features)
Edit with Rollback
Makes the selected feature the current feature and enters the edit mode.
Edit
Enters the feature edit mode without changing the current feature. To edit sketches directly in Modeling, you should:
Set Double-click Action (Sketches) to Edit with Rollback. Set Edit Sketch Action to Direct Edit.
Right click the sketch and choose Edit. Where do I find it?
Application Modeling
Menu Preferences→Modeling
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b) Create and Reattach Sketch
Use the Sketch command when you need to define the sketch plane, orientation, or origin, in a manner not available using the inferred plane method.
The commands to create and reattach a sketch use the same dialog box and options. These Help topics will discuss both commands.
Use the Sketch command to create sketches on the following:
On Path
On Plane using the following methods:
o Inferred Plane
o Existing Plane
o Create Plane
o Create Datum CSYS
Use the Reattach command to:
Move a sketch to a different plane, face, or path.
Switch a Sketch in Place to a Sketch on Path and vice versa.
Change the location of a sketch on path along the path to which it is attached. Where do I find it?
Create a sketch
Toolbar
(Modeling) Direct Sketch→Sketch
(NX Sheet Metal and Shape Studio) Insert→Sketch in Task Environment Menu Insert→Sketch
Reattach a sketch
Toolbar
(Modeling) Direct Sketch→Reattach
(Sketch task environment) Sketch Tools→Reattach Menu (Modeling and Sketch task environment) Tools→Reattach
Reattach a Sketch in Place
1.
Double-click any curve in the sketch to open it for edit. 2. Click Reattach . 3.
Select the target face.
日 4.
In the Sketch Orientation group, click Select
Reference .
5.
Select the new reference object.
6.
In the Sketch Origin group, click Specify Point .
7.
Select the new origin.
8.
To reattach the sketch, click the middle mouse button.
Reattach a Sketch on Path
1. If the target sketch is internal to a Variational Sweep, Extrude, or Revolve feature, you must externalize the sketch before you can reattach it. Right–click the parent feature in the Part Navigator and choose Make Sketch External.
2. Ensure that the target face, plane, or path appears before the sketch in Timestamp Order. If necessary, right–click the target entity in the Part Navigator and use Reorder Before or Reorder After to change the Timestamp sequence.
3. Open the sketch and, on the Sketch toolbar, choose Reattach .
4. Keep the On Path option if you are moving the sketch to another path, or choose On Plane if you are moving the sketch to a planar face or a datum plane.
5. If you are moving the sketch to another path, shift–click the current sketch curve to deselect it. 6. Select the target path, face, or datum plane.
7. Redefine the sketch location as necessary for your part.
Note Use Reattach to change the location of a Sketch on Path along the path to which it is attached.
Copy a sketch to a new location
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1. Click here to download the part.
Click Open . Open copy_sketch.prt.
2. In the Part Navigator, select the features
to copy:
Select Sketch (11) “SKETCH_001”. Hold the Shift key and select Edge Blend (15).
Press Ctrl+C, to copy the highlighted features.
Press Ctrl+V, to start the Paste Feature command.
The Paste Feature dialog box displays a List of the references required to complete the Paste operation.
The two references in the List display (-) to indicate that they have not been
satisfied. As you select new references, the list will display (+).
The edge that the original sketch Datum Coordinate System is attached to now highlights.
3.
Select a new sketch reference:
Place your cursor over the edge so that the preview arrow displays in the same
direction as shown. Select the edge.
The next edge that the original Sketch External Reference is attached to now highlights.
The first reference in the List displays (+) to indicate that it has been satisfied.
4.
Select a new sketch reference:
Place your cursor over the edge so that the preview arrow displays in the same
direction as shown. Select the edge.
The edge highlights and displays a
direction vector. If the direction is wrong, double-click the direction vector to reverse it.
Both references in the List display (+) to indicate that they have been satisfied.
5. Associate the feature parameters of the
copy to the original feature parameters: In the Settings group, from the
Expressions list, choose Link to Original.
Click OK to copy the features.
日 6.
Double-click the sketch to edit the Sketch Origin.
7.
Click Reattach Sketch .
8.
In the Sketch Origin group, click Specify
Point .
9.
Select the End Point of the edge as shown. Right-click in the graphics window and choose Finish Sketch .
Create and Reattach sketch dialog box
On Plane
Lets you sketch in place, either on an existing plane or face, or on a new plane or CSYS.
On Path
Lets you sketch on a path, constructing input for commands like Variational Sweep. On Plane options
Sketch Plane
Plane Method Inferred
Lets you select a plane or planar face that appears before the sketch in Timestamp order. This options infers the sketch orientation, and origin. Existing Plane
Lets you select a plane or planar face that appears before the sketch in Timestamp order. This options requires you to select the sketch orientation, and origin.
Create Plane
Lets you specify a plane using either the Plane Dialog or the Inferred list. Create Datum CSYS
Lets you create a new Datum CSYS. Sketch Orientation
Reference Sets the reference direction for the sketch to either horizontal or vertical.
Select Reference Specifies the horizontal or vertical reference for the sketch. Any horizontal or vertical constraints you add to the sketch are relative to this reference direction. Whenever possible, NX infers a reference direction from your face or plane selection. To change the inferred direction, select an appropriate edge, datum axis, datum plane, or face.
Note A reference direction is required for a Sketch in Place. NX uses the reference direction to orient a sketch when you copy or reattach it, or use it in a UDF. Sketch Origin
Specify Point Specifies where to locate the origin of a new sketch.
If you do not specify a point, NX infers the sketch origin point from the nearest control end point of the plane or planar face you select.
Settings
日
Datum CSYS feature used to create the sketch. This option also gives the sketch independence so
that if you delete the base feature the sketch remains. Associative
Origin
Available only when Create Intermediate Datum CSYS is selected. Associates the sketch origin to the selected object.
Project Work Part Origin
Infers the sketch origin point from the origin point of the work part. Use this option to sketch in absolute world coordinates.
Note The current sketch plane must be parallel to one of the three principle planes.
The Sketch Origin setting does not apply to a Sketch on Path. On Path options
Path
Select Path Selects the target path. A path can contain multiple, tangent-continuous segments. Valid
input types are: Curves.
Edges of sheets or solid bodies. Plane Location
Location Specifies how you want to define the location of the sketch plane along the path.
% Arc Length
Lets you specify the plane location as a percentage from the path's start point.
Arc Length
Lets you specify the plane location as a number of units from the path's start point.
Through Point
Lets you pick the plane location using the cursor (with or without snap point options) or by specifying X and Y coordinates.
Alternate When you set the plane location to Through Point and select an external point, this
Solution
Plane Orientation
Orientation Specifies the direction of the sketch plane: Normal to the Path
Sets the sketch plane normal to the path on which you are sketching. Normal to Vector
Sets the sketch plane normal to a specified vector using the Vector dialog. Parallel to Vector
Sets the sketch plane parallel to a specified vector using the Vector dialog. Through Axis
Aligns the sketch plane to a specified axis using the Vector dialog. Sketch Orientation
Method Relative to Face
Ensures that NX orients the sketch to a face, either inferred or explicitly selected. The path location you select determines the direction of the sketch plane normal. Use Curve Parameters
Ensures that NX orients the sketch using curve parameters, even if the path is an edge, or is part of a feature that lies on a face.
Automatic
Preserves the default Sketch on Path orientation behavior from NX 5. If you select a curve, NX orients sketch axes using curve parameters. If you select an edge, NX orients the sketch axes relative to the face, or one of the faces, that owns the edge.
Sketch Horizontal Reference
Specifies the horizontal reference for the sketch. Select a face, edge, datum axis, or datum plane. When you select an edge, NX points the reference axis toward the closest end point. Any horizontal or vertical constraints you add to the sketch are relative to this reference direction. Also note that NX uses the reference direction to orient a sketch when you copy or reattach it.
Intermediate Datum CSYS
NX can automatically create an Intermediate Datum CSYS when you create or reattach a sketch. By default, the Intermediate Datum CSYS is internal to the sketch. It is not visible outside the sketch or in
日 Why should I use it?
Select this option to associate theIntermediate Datum CSYS to the base feature used to create the sketch. This option also gives the sketch independence so that if you delete the base feature the sketch remains. You can make this Datum CSYS:
External from the sketch when you right-click the sketch in the Part Navigator and choose Make Datums External.
Internal to the sketch when you right-click the sketch in the Part Navigator and choose Make Datums Internal.
Where do I find it?
Toolbar
Direct Sketch→Sketch
Feature→Sketch
Menu
Insert→Sketch
Insert→Sketch task environment
Location in dialog box Settings group→Create Intermediate Datum CSYS
c) Sketch groups
You can create groups in a sketch to organize geometry and dimensions. Groups an be especially useful in large or complex sketches. For example, you can:
Set a group to actively collect new geometry and dimensions as you create them. Assign an Object Color to all the group members in one step.
Turn the visibility of the group on/off. Active and inactive groups
Create an Active group when you want to add new objects to a group. NX continues adding objects to an active group until you turn its active status off. Create an inactive ( ) group when you want to add a set of existing objects to a group and then stop collecting in that group.
Here is a view of one active group and one inactive group as they appear in the Part Navigator: Groups Group ‖OUTER_PROFILE‖ Arc ―Arc3‖ Line ―Line1‖ Line ―Line2‖ Group ―INNER_PROFILE‖ Arc ―Arc1‖ Arc ―Arc2‖
Model History
Datum Coordinate System (0) Sketch (1) ―SKETCH_000‖
Group ―OUTER_PROFILE‖ Group ―INNER_PROFILE‖ Where do I find it?
Menu Format→Group→New Sketch Group (creates a sketch group)
Format→Group→New Active Sketch Group (creates a new empty active sketch group)
Add sketch geometry and dimensions to a group
This example shows how to add geometry and dimensions from the following sketch to a sketch group.
1. Double-click a sketch curve.
2. Choose Format→Group→New Active Sketch Group. 3. Select the curves and dimensions you want to add.
4. (Optional) Enter a name for the new group that you want to create.
5. If you do not want to continue adding curves and dimensions to this group, clear the Active check box.
6. Click OK.
In the Part Navigator, NX updates the Sketch and Groups nodes. Groups
Group ‖OUTER_PROFILE‖ Automatic Parallel Dimension Line ―Line1‖
Line ―Line2‖ Line ―Line3‖ Line ―Line4‖ Model History
日 Group ―OUTER_PROFILE‖
Manage sketch groups with the Part Navigator
Part Navigator displays groups under the respective Sketch node and in the Groups node.
Right–click on a group and select Active to make the group active. New geometry that you add to the sketch will belong to the active group.
Drag and drop objects to move them from one group to another group, or from a group to the Curves and Dimensions node.
Drag and drop a group icon to nest the group in another group.
Select/clear the group box to turn the visibility of all curves/points in the group on or off. Add and manage sketch dimensions within Groups.
Right–click on a group and select Edit Display to set the Object Color for all the group members. Right–click on a group and select Ungroup to delete the group. The sketch removes the group,
but not the group members.
Right–click and choose Delete to remove both a group and all its members.
d) Orient View to Sketch
Use Orient View to Sketch to orient the view so that you are looking directly down the Z axis on the sketch plane.
Where do I find it?
Toolbar
(Modeling) Direct Sketch→Orient View to Sketch
(Sketch task environment) Sketch Tools→Orient View to Sketch Menu (Modeling and Sketch task environment) View→Orient View to Sketch
e) Orient View to Model
Use the Orient View to Model command to orient the sketch to the view of the part that applied when you started Sketch task environment.
Where do I find it?
Task environment Sketch
Toolbar Sketch→Orient View to Model
Menu View→Orient View to Model
f) Delaying Sketch updates
Use the Delay Update During Edit of Sketch to delay updating the model from the sketch while sketching directly in Modeling, Shape Studio, or Sheet Metal.
You can then use the Update Model from Sketch command to update the model to reflect all the changes you made to the sketch.
Video
This video demonstrates how Delay Update During Edit of Sketch and Update Model from Sketch work with each other.
Why should I use it?
When you edit a sketch directly in an application, the dependent features are updated for every sketch modification you make. You can use these commands to streamline the editing of a sketch that has many dependant features.
You can first implement a series of sketch edits and then see the results of the edits. This creates a streamlined workflow because you update the model when you are ready.
Where do I find it?
Application Modeling, Shape Studio, Sheet Metal
Toolbar
Direct Sketch→Delay Update During Edit of Sketch
Direct Sketch→Update Model from Sketch
Menu
Tools→Update→Delay Update During Edit of Sketch Tools→Update→Update Model from Sketch
g) Delay Evaluation
Use the Delay Evaluation option to delay the update of sketch constraints until the Evaluate Sketch option is chosen.
When you create curves, NX does not show constraints.
When you assign constraints, NX does not update the geometry until you select the Evaluate Sketch option.
Note This command does not delay evaluation when you drag curves, or when you use the Quick Trim or Quick Extend commands.
Where do I find it?
Task environment Sketch
Toolbar Sketch→Delay Evaluation
Menu Tools→Update→Delay Sketch Evaluation
h) Evaluate Sketch
Use the Evaluate Sketch option to update the current sketch with the constraints applied, modified, or deleted while the Delay Evaluation option was selected. This option is only active when Delay Evaluation is selected.
日 Where do I find it?
Task environment Sketch
Toolbar Sketch→Evaluate Sketch
Menu Tools→Update→Evaluate Sketch
i) Update Model
Use the Update Model command to update the model with changes you have made to your sketch. The model updates automatically when you exit the Sketch task environment. When you edit a sketch with Rollback, there are no later features to update so this command is not available.
Why should I use it?
Update Model is useful in the Sketch task environment because it lets you see the effect sketch changes have on later features.
Prerequisites
Set the following in the Modeling Preferences dialog box to make the Update Model command available.
Edit tab
Double-click Action (Sketches)
Edit
Enters the sketch without changing the current feature.
Edit Sketch Action
Task Environment
Enters the Sketch task environment. Where do I find it?
Task environment Sketch
Toolbar Sketch→Update Model
j) Replace with Independent Sketch
Use the Replace with Independent Sketch command to replace a linked curve feature with an independent sketch.
This command will replace a WAVE linked sketch or a two-dimensional linked composite curve with an identical sketch that is completely independent of the parent.
Use this command when you no longer want a design to be controlled by its master layout.
Example During the design and development of a product, you may have a master layout to control the design of many component parts. When the designs are released for manufacturing, you do not
want the components to change if the master layout is changed. To do this, you can break the link and replace the linked sketch with an independent sketch. An additional advantage is that the replaced independent sketch has its own constraints that you can modify.
Where do I find it?
Application Modeling
Toolbar Edit Feature→Replace with Independent Sketch Menu Edit→Feature→Replace with Independent Sketch
Part Navigator Right-click a Linked feature→Replace with Independent Sketch
k) Rename a sketch
From the Sketch task environment
1. On the Sketch toolbar, from the Sketch Name list, select the sketch. 2. Type a new name and press Enter.
From the Part Navigator
1. Right–click a sketch feature and choose Properties. 2. Click the General tab.
3. Type a new name in the Name box. 4. Click OK.
l) Finish Sketch
Use the Finish Sketch command to exit a sketch and return to the application or command you started sketching from.
Where do I find it?
Toolbar
(Modeling) Direct Sketch→Finish Sketch
(Sketch task environment) Sketch Tools→Finish Sketch Menu (Modeling) File→Finish Sketch
(Sketch task environment) Task→Finish Sketch Keyboard Ctrl+Q
m) Exit Sketch
Use the Exit Sketch command to exit the Sketch task environment without doing the following: Saving the modified sketch.
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The Exit Sketch command restores the part to the state it was prior to entering the Sketch task environment while avoiding the unnecessary step of updating all features downstream of the sketch. Why should I use it?
Use this command when you want to do the following:
Explore and edit sketch curves and constraints without changing sketches and the model permanently.
Discard sketch edits made since you entered the Sketch task environment. Where do I find it?
Task environment Sketch
Menu Task→Exit Sketch
6. Creating and editing geometry
View a topic
Profile Line Derived Lines Arc Circle Fillet Chamfer Rectangle Polygon Studio Spline Fit Spline Ellipse Conic Sketch Point Offset Curve Pattern Curve Mirror Curve Intersection Point Add Existing Curves Intersection Curve Project Curve Quick Trim Quick Extend Make Corner Trim Recipe Curve Edit Defining Sectiona) Profile
