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Solid Edge ST6 First Looks: Surfacing Refined

By Jeffrey Opel, October 10, 2013

Solid Edge has always had best-in-class surfacing, and competing software packages are just now fortifying their surface offerings.

Other MCAD systems I have used would require me to extract surface edges, cut the wireframe sections, and then fair the resulting splines, before applying a new surface. This, naturally, takes longer and requires me to create extensive construction geometry, planes, and so on. This approach in other MCAD systems requires that we have a strong command of 3D wireframe modeling, which is not so common anymore. (We old-school technical surfacers were weaned on this approach.) Figure 1 shows this traditional, more cumbersome approach to replacing surfaces.

Figure 1: Traditional approach to replacing surfaces

As I found out, Solid Edge ST 6 makes the process a lot easier. Surfacing in Solid Edge ST 6 is refined through new commands that show up on the ribbon, such as Surface Redefine and Surface Intersect. In this First Look, I take a look at the functions these two commands perform.

Redefining Surfaces

The Surface Redefine command creates surfaces by combining existing model faces. Figure 2 shows where to find the new command on the ribbon.

Figure 2: Solid Edge ST6 ribbon for creating surfaces

The on-line "What's New" documentation for the command was sparse, but I was nevertheless able to work out how to use them with little assistance. For example, the documentation for the Redefine command described a simple example, that of replacing the bib of a baseball helmet (see figure 3).

Figure 3: Example object made of surfaces in Solid Edge documentation

I would rather go BIG with a really tough example, such as replacing a pesky patchwork of surfaces on this boat hull (see figure 4).

Figure 4: My larger example of a boat hull

The task of redefining surfaces is pretty straightforward in Solid Edge ST 6. After I started the command, Solid Edge popped up a floating toolbar panel; its buttons marched me along through the process (see figure 5). All I had to do was go step by step, from left to right.

Figure 5: Command panel for redefining surfaces

In addition to the command panel, the command prompt bar at the bottom of the Solid Edge screen proved handy in prompting me for the next step to take (see figure 6).

Figure 6: Prompt bar telling me what to do next

Despite the wording of the name, I found that the Surface Redefine command works on either surface models or faces of solid models. I like that.

I had the command working in both Synchronous Mode and Ordered Mode. When I asked Siemens PLM for some additional help, their technical people steered me towards employing Ordered Mode for final usage.

(OK, now I feel I need to explain the difference between the two modes: think of Ordered Mode as the traditional feature-based solids modeling environment, complete with history tree. In contrast, Synchronous Mode is like the direct modeling approach, with no regard for part history or sequence of operations.)

Here is how the Refine Surface command actually works:

  1. Select the command, and then click the faces to be replaced (see figure 7).

Figure 7: Selecting faces for replacement

  1. Explore the command options, by clicking them from left to right. Shown in figure 8 are the options of the Redefine Surfaces dialog box. In this case, I took advantage of the system's default settings.

Figure 8: Dialog box with options for redefining surfaces

  1. While I was redefining some surfaces, I could pop into the Surface Visualization option to display curvature combs along user-defined surface flow line densities (see figure 9).

Figure 9: Visualizing the redefined surface

  1. In this big "tuning step," I adjusted the surface curvature parameters, such as tangent, curvature, and continuous (see figure 10).

Figure 10: Adjusting surface parameters

And here are the before and after the redefinition process of the surfaces, shown in figures 11 and 12.

Figure 11: Many surfaces before refinement...

 

Figure 12: ...and one surface after refinement

Intersecting Surfaces

The Intersecting Surfaces command extends or trims selected surfaces to a common intersection. Figure 13 shows where to find the new command on the ribbon.

Figure 13: Command for intersecting surfaces

Looking for more information on this command, I found that the on-line "What's New" documentation was very limited: it consisted of a single sentence. So, I dug deeper to find a basic example of how it really works.

It turns out that the command is really not a new function; in Solid Edge, we could always trim and extend surfaces. And so in my view, the Intersect command is a productivity enhancement, in that it combines two commands into one: Trim Surface and Extend Surface (see figure 14).

Figure 14: Trim and Extend commands combined into one command in Solid Edge ST6

Figure 15 illustrates the example surfaces I found in the Solid Edge help pages. I was able to use it to figure out the workflow.

Figure 15: Example object using Intersect Surface in Solid Edge documentation

I decided that I could come up with something a little more fun to work with. Figure 16 shows the surfaces I drew (left), while on the right you see them after being cleaned up with the new Intersect Surface command.

Figure 16: Model before (left) and after having surfaces intersected

Let me walk you through the steps I took.

  1. When I started the command, this handy toolbar panel popped up to guide me through the command execution, working from left to right (see figure 17).

Figure 17: Intersect Surface toolbar panel

  1. As the command started, I was prompted to select the surfaces. This is the point at which all of the magic happens: the system calculates all of the possible trim and extend operations at this time.
  2. After this, I just had to select which surfaces I wanted trimmed (see figure 18), or which edges extended (see figure 19).

Figure 18: Intersect Surface using the trim option

Figure 19: Intersect Surface using the extend option

  1. I took advantage of the Stitch Surfaces option to join the sides with the top (see figure 20).

Figure 20: Stitch Surfaces option of the Intersect Surfaces command

  1. This option allowed me to place a rolling ball fillet between the two surfaces with ease (see figure 21).

Figure 21: A rolling ball fillet placed as a result of the Stitch Surfaces option of the Intersect Surfaces command.

So, we've seen how Solid Edge ST6 trims and extends surfaces during the same command. What I found fascinating was that it could trim off a portion of a surface, and in the same motion extend another part of it. Excellent!

Conclusion

In addition to the ones I highlighted, there are many commands, options, and functions available to surface designers. For example, I found that the number of surfaces I selected impacted the command functionality.

The new commands will save you a lot of time by not having to repeatedly extend and trim surfaces to achieve the desired result.

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About the Author

Jeffrey Opel has been a CAD and engineering manager. He has over 25 years experience in mechanical design. More...

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