Product help with community knowledge

### Community Scoring

Was this page helpful?

### Tag Tags0

This page has no tags

### Page statistics

9236 views1 edit(s)41679 characters(s) Page last modified 23:17, 23 Mar 2011 by adsk_arutherford

# Work points

##### Table of contents

Work features are abstract construction geometry used when geometry is insufficient for creating and positioning new features. To fix position and shape, constrain features to work features.

Work points can be placed or projected onto part faces, linear edges, or onto an arc or circle. Work points can be constrained to the center points of arcs, circles, and ellipses.

How are work points used?

• Mark shaft and pattern centers
• Define coordinate systems
• Define planes (three points)
• Define 3D paths

When creating 3D sweeps, you can place a work point at the intersection of work axes and work planes. You click work points and vertices of existing parts to define the path of the sweep.

How are ungrounded and grounded work points different?

Grounded work points have all degrees of freedom removed and are therefore fixed in space. An ungrounded work point can be repositioned by dimensions or constraints.

In a part file, use the Grounded Point command. When you create a grounded work point in a part file, the 3D Move/Rotate command is available so that you can specify certain operations relative to the grounded work point. Or, use the 3D Move/Rotate option on the context menu later to reposition the work point.

In an assembly, you first create a work point, right-click, and then select Grounded from the context menu. The 3D Move/Rotate command is not available in an assembly file.

What controls the position of a grounded work point?

To ground a work point in a part file, select it in the browser, right-click, and then select Ground.

• The work point position is originally determined by the geometry you selected to create it. When you select Ground, the relationship to the selection geometry is removed. The work point remains fixed in space, even if the selection geometry is moved or resized.

If you clear the check mark on the Ground menu option, the associative relationship is restored. Changes to the selection geometry reposition the work point.

• When you use 3D Move/Rotate to edit a grounded work point, the relationship to the original selection geometry is permanently removed. You cannot restore an associative relationship to the original geometry used to create the work point.

When you use Grounded Work Point on the Model tab, the created work point has no association to other geometry. It is fixed on the X, Y, and Z coordinates used to create it.

How is a grounded work point edited?

In a part file, right-click the grounded work point in the browser, and then choose one of the following options:

• Select the 3D Move/Rotate option.

If geometry was used to position the work point, it is no longer associated to the work point. The work point remains grounded.

• Select the Redefine Feature option.

The work point becomes associative to new geometry that you select. Changes to the geometry reposition the work point.

Procedures

Create a work point (legacy method)

On the Model tab, Work Features panel, use Point or Grounded Point in a part file to select model vertices, edge and axis intersections, intersections of three nonparallel faces or planes, and other work features as work points. You can also create work points as input to other work feature commands that require you to select a point.

In an assembly file, use the Point commands on the Model tab. Work points can be created at the intersection of part faces, edges, vertices, and work geometry that span hierarchical levels in the assembly.

Work points can be placed on holes and cuts in part faces, model surfaces, construction surfaces, and base surfaces. When Loop Select Mode is active, you can place a work point on one or more closed loops.

TipTo understand geometric dependencies, right-click a work feature in the browser or the graphics window, and then select Show Inputs. For example, you can right-click a work point to highlight the geometry from which it was created, such as a work axis and a work plane.

Prior to the introduction of Direct Manipulation modeling techniques in Inventor R2011, the Point command was the only method available to create work points. This legacy method was, and still can be, used with one of the methods described below:

Show Me how to create a grounded work point

## Show Me how to create a work point with reference to an in-line work axis

Create a work point from one selection

 On the ribbon, click Model tabWork Features panel Point. Move the cursor over the model to highlight valid work point locations. Right-click and select Loop Select mode from the pop-up context menu. When Loop Select mode is on, selection priority is loops on parts. On the active part or feature, click one of the following to place the work point: A loop, such as the edge of a cylindrical feature or a cut. Analytic curve Non-analytic closed loop curve

Show Me how to create a midpoint or vertex work point

Create a work point from multiple selections

 Select two or more geometric elements to create a work point at the intersection of planes or the projection of two edges. On the ribbon, click Model tabWork Features panel Point. Select two elements on the active feature or part: Planar face or work plane and a sketch line, straight edge, or work axis. Surface and a sketch line, straight edge, or work axis. Planar face or work plane and a curved edge or other sketch curve (arc, circle, ellipse, or spline). Two lines (sketch lines, straight edges, or work axes). Three planar faces or work planes.

Show Me how to create a two-axis or two-edge work point

Show Me how to create a three-plane work point

Show Me how to create a work point at the intersection of a plane and edge

Show Me how to create a work point at the intersection of a spline and plane

Create an assembly work point

 On the ribbon, click Model tabWork Features panel Point. Click one: A component vertex. The intersection of three planes. A planar face or work plane and a straight edge or work axis. A work axis or linear edge and an intersecting work axis or linear edge. Assembly work points are placed at the bottom of the assembly hierarchy in the browser. NoteIn an assembly, in-line work features are not available and midpoints are not selectable.

Create a grounded work point in a part file

Specify X, Y, and Z coordinates to ground a work point. The work point remains fixed in space regardless of changes to model geometry. When creating a grounded work point , in-line work features are not available.

 On the ribbon, click Model tabWork Features panel Grounded Point. Click a work point, midpoint, or vertex. A pushpin cursor symbol indicates the selection is grounded. The 3D Move/Rotate command displays with its axes aligned with the principal axes of the part. Click or drag an axis or center of the command, then enter values in the 3D Move/Rotate dialog box and click Apply. Repeat until the appropriate X, Y, and Z coordinates are defined.
NoteYou can ground an associative work point, and then unground it if the point is not moved. If you move the point using the triad, you cannot change it back to an associative work point.

Show Me how to create a grounded work point

Show Me how to redefine the alignment or position of the 3D Move/Rotate command

Create a grounded work point in an assembly file

You can fix a work point in 3D space in an assembly file. Changes to model geometry do not affect its position. All degrees of freedom are removed from the grounded work point .

1. On the ribbon, click Model tabWork Features panel Point.
2. Click geometry to position the work point.
3. Right-click the work point symbol in the browser, and then select Grounded.

The 3D Move/Rotate command is not available in an assembly.

Although still valid, the Point command has been enhanced in Inventor R2011 to now present the Inventor user with a convenient drop-down menu listing each of the possible combinations available for work point creation.

Each of these new options is described on the Quick Reference tab of this Help topic.

References

Work points

A work point is a parametric construction point that can be placed on part geometry, construction geometry, or in 3D space. In an assembly, a work point cannot be created on the midpoint of a line.

Work points can be placed on holes and cuts in part faces, model surfaces, construction surfaces, and base surfaces. When Loop Select Mode is active, you can place a work point on any closed loop.

 Access: In a 3D sketch, click ModelWork Features and then click Point or Grounded Point. In a part file, click ModelWork Features and then click Point or Grounded Point. Alternatively, select an explicit work point creation method from the Point drop-down menu. In an assembly file, click Model tabWork Feature panel Point.

In a part, an ungrounded work point can be created in-line while using another work feature command. The Point command terminates as soon as the work point is created.

TipTo understand geometric dependencies, right-click a work feature in the browser or the graphics window, and then select Show Inputs. For example, you can right-click a work point to highlight the geometry from which it was created, such as a work axis and a work plane.

The Point drop-down menu offers the following work point creation options:

 Point (legacy method)Select the appropriate model vertices, edge and axis intersections, or intersections of three nonparallel faces or planes to create a work point. Grounded PointClick a work point, midpoint, or vertex. A pushpin cursor symbol indicates the selection is grounded. On Vertex, Sketch point, or MidpointSelect a 2D or 3D sketch point, vertex, or the endpoint or midpoint of a line or linear edge. Intersection of Three PlanesSelect three work planes or planar faces. Intersection of Two LinesSelect any combination of two lines including linear edges, 2D or 3D sketch lines, and work axes. Intersection of Plane/Surface and LineSelect a planar face or work plane and a work axis or line. Alternatively, select a surface and a sketch line, straight edge, or work axis. Center Point of Loop of EdgesFirst, right-click and select Loop Select from the pop-up context menu. Then select one edge of a closed loop of edges. Center Point of TorusSelect a torus.