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I hope you are not growing tired of my SolidWorks World chronicles just yet, because I still have a lot more to write about. This was a particularly good SolidWorks World for me and I want to share what I learned with you.  This time, let me tell you about yet another hands-on session I attended. This one was presented by Michael LaFleche, Regional Technical Manager for CAPINC, and it was an introduction to direct modeling techniques in SolidWorks for those of us that hadn’t really tried that functionality before or didn’t know how we could benefit from it.

He began by showing us some common ways to do modifications in the geometry of an imported part. As you know, usually when you import a part -step, parasolid, iges, etc-  you are not going to have access to its features to modify any dimensions. Since all you usually have is an imported feature (dumb part) or imported surfaces,  it’s common practice to do modifications via the “Butcher Approach”, as Michael calls it, and that is basically slashing, moving and  then reconnecting and patching parts of the geometry.  He demonstrated this approach through an example.

Michael started with a step file that he opened in SolidWorks. After running import diagnostics and healing a couple of faces, we had no features on that tree. Michael used the “Butcher Approach” to make the legs of this part you see here  a little longer. First, he began by slashing the model using a line that was sketched on the Front plane and the Split command (Insert, Features, Split). This way, he cut the model in three solid bodies: the frame and two of its legs. They are all in the same color in the image, but you can see there’s actually three bodies and each one has a callout right next to it.  The three solid bodies will appear in the Solid Bodies folder in the Feature Manager tree.

Next, he used Move/Copy Body  (Insert, Features, Move/Copy Body)  to translate both legs down by 20 mm. Note that Move/Copy Body also has the option of using constraints. We don’t want to use constraints, so make sure to choose Translate/Rotate under options in the Move/Copy Body property manager. You will see a Triad appear. You can use this triad to dynamically move the bodies down by dragging the green arrow, or you can enter numerical values for the new position directly from the property manager on the left.

By now, both legs have moved down and now there’s a gap that needs to be filled.

Michael used the Boundary Boss feature to fill the gap and reconnect the bodies. He could’ve also used loft or even a surfacing technique, but Boundary Boss did the trick this time.  So there you have it, the Butcher Approach.

Next, he showed us a direct modeling approach, using Move Face. First, we needed to turn on the Direct Editing Command Manager tab by right clicking on any of the other tabs and selecting Direct Editing from the list.

He used Move Face to translate those six faces you see here ten millimeters towards the inside of the leg. Notice that we needed an edge to specify the direction of translation, so we used the one you see highlighted there next to the pointer. The preview of the new location appears in yellow.

Something important: Once we accept the Move/Face feature, it will show up in the Feature Manager as an other feature that can be edited, but not only that, we can now use Instant3D to dynamically drag a face in this leg, for instance, as you see in the image below. Notice that dragging the face with Instant3D doesn’t add another feature to the tree because, in fact, every time you drag the face using Instant3D you are simply editing the Move Face feature that had been added previously.

Move Face can also be used to offset a face in a body, like you see in the following image. Here, Michael instructed us to offset the face highlighted in blue 1 mm towards the part. Once we accept the feature, all other faces around it will be modified accordingly and, just as before, we’ll be able to use Instant3D to dynamically drag this face.

There’s also an option to rotate the face instead of moving it or offsetting it. To use this option we need to specify an axis for rotation and an angle. In this image, the vertical edge on one side of the face was used as the axis and we rotated the face 15 degrees from its original position.

Notice that once we accept the Move Face feature the hole doesn’t show up in the face we just rotated, but that all the rest of the geometry has changed accordingly and the hole now shows up going through other faces in the part.

Michael corrected this situation by using Move Face again to translate the geometry associated with the hole. Notice the edge of the face that is used to specify the direction of translation. The preview of the new location shows up in yellow.

He also demonstrated the use of this technique in a large model when he used Move Face to change the location of some of the support ribs on this engine block. By the way, those ribs are not really part of a pattern, but Michael did mention that Move Face can be used to change the location of one, two or more instances inside of a pattern without disturbing the rest of the pattern.

He first changed the model to a Right side view and Wireframe display style to make it easier to select the geometry. He used Move Face command again to translate the faces of two of the ribs. He selected the faces associated to the ribs  by dragging a box from left to right as you see in this image.

Once the faces were selected, he used a horizontal edge in the part to specify the direction of translation and moved the geometry 2 in to the right. It’s a bit hard to appreciate in this image, but there’s a preview of the new location of the ribs. The lines in blue are the ribs in their original position, and the preview shows up in yellow.

Michael also showed us how to use FeatureWorks to recognize features in an imported part. This can be done locally, by right clicking on a face, for instance, and selecting Edit Feature from the flyout toolbar. FeatureWorks then will recognize features such as extrudes, holes, revolves, etc. that could be associated with the geometry selected. We can also recognize features in the whole model at once by right clicking on the imported feature in the Feature Manager tree and selecting FeatureWorks, Recognize Features, as you see in the following image.

FeatureWorks will then recognize features such as extrudes, revolves, holes, ribs, fillets, etc. and create a Feature Manager tree for the part. This can save some time and effort. For instance, after recognizing features in this imported part, I suppressed the ones that were associated with the engraved plate.

I believe the complete presentation with files and step by step instructions will be available in March. Until then, as usual, I hope my brief chronicle was useful for someone out there.

Thanks to Michael LaFleche for a great hands-on presentation. I really enjoyed it.

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