To Create a Variable Section Sweep
1. Choose Advanced and Done from the SOLID OPTS or SRF OPTS menu. The system displays the ADV FEAT OPT menu.
2. Choose Var Sec Swp, then Done from the ADV FEAT OPT menu. Pro/ENGINEER displays the feature creation dialog box and the VAR SEC SWP menu.
3. Choose an option from the SWEEP OPTS menu, then choose Done. The options are as follows:
NrmToOriginTraj—Select the Origin Trajectory.
Pivot Dir—Use the GEN SEL DIR menu to specify the Pivot Direction. The options are as follows:
- Plane—Select a plane or create a new datum plane to which the direction will be normal.
- Crv/Edg/Axis—Select as the direction an edge, curve, or axis. If you select a non-linear edge or curve, the system prompts you to select an existing datum point on the edge or curve to specify a tangent.
- Csys—Select an axis of the coordinate system as the direction.
Norm To Traj—Select the Origin Trajectory and an additional trajectory to which the section will remain normal.
4. Sketch or select the Origin Trajectory using the VAR SEC SWP menu options, then choose Done. The options are as follows:
Sketch Traj—Sketch a new trajectory to use for the sweep.
Select Traj—Define a chain from curves and edges (such as a datum curve) to use as the sweep trajectory.
Sel Tan Traj—Define a chain from curves and edges to use as a trajectory and specify a tangency condition by selecting tangency reference surfaces.
Remove Traj—Remove a trajectory that you previously sketched or selected. You cannot remove the Origin Trajectory.
5. If you chose Pivot Dir in Step 3, go to Step 8; otherwise, proceed as follows:
Sketch or select the X-Trajectory, which defines the horizontal vector of the section. The sketching plane is located at a datum point or the endpoint of the
Origin Trajectory. The orientation of the sketch plane is such that the positive X-axis passes from the endpoint of the Origin Trajectory through the point at the
intersection of the second trajectory with the normal plane.
6. If you chose Norm To Traj in Step 3, select the trajectory to which the section will be normal. Choose an option in the SEC ORIENT menu, followed by Done:
Norm to Surf—Select a surface that determines the section’s upward direction, then select or sketch the trajectory that defines the section plane normal.
Choose Flip an Okay to select the upward direction. This option is available only if the Origin Trajectory belongs to a surface.
Use Norm Traj—Select a trajectory that defines the section plane normal.
7. If the Origin Trajectory has datum points, the system highlights an endpoint of the Origin Trajectory so you can define the start point. Choose an option from the SEC POINT menu to select the start point:
Origin Start—Use the highlighted endpoint as the start point for the Origin Trajectory.
Pick Point—Pick a datum point on the Origin Trajectory to be its start point.
Note: For a Norm To Traj variable section sweep, the system checks if the normal plane to the selected trajectory has a defined intersection with the
Origin Trajectory. If the intersection cannot be found, the system issues a warning so you can redefine the normal trajectory.
8. You can sketch or select as many additional longitudinal trajectories as you want, such that if the section is dimensioned to or aligned to these trajectories, the
sweep feature also follows these trajectories as it travels along the origin. The trajectories can be accessed by selecting the Trajectories element in the
dialog box. You can remove a trajectory by choosing Remove Traj from the VAR SEC SWP menu.
9. Choose Done to complete the trajectory definitions.
10. Sketch the sweep section. The section can be dimensioned to known points (to the points of intersection of the longitudinal curves with the sketching plane).
The section remains aligned and dimensioned to the point as it sweeps along the curve.Use relations to create a meaningful parametric section.
11. Choose Done to exit Sketcher.
12. Click OK in the dialog box.
What is evalgraph?
Evalgraph is a system parameter used for driving dimensions in Sketcher relations of swept features, according to a user-defined graph feature.
The y-axis of the graph feature drives the dimension as the section travels along the trajectory represented
by the x-axis.
Evalgraph is used in conjunction with trajpar.
What is "trajpar" and how is it used?
Trajpar is a value normalized along the origin trajectory of a variable section sweep.
The value can vary from 0 to 1 as the section is swept.
Trajpar is a trajectory parameter which can be used in a sketcher relation to "map" a graph or any functional equation along the variable section sweep feature.
By using trajpar in a sketcher relation the driving dimensions in the section can be varied as the section sweeps along the origin trajectory.