CAD in Context, How Physical Parts Factor-In to Your Digital PLM World

Do you have physical parts laying around with no CAD? Have you invested substantial amounts of money in PLM or PDM systems, only to have a large portion of your products sitting squarely outside this system? As 3D Imaging has progressed, we see it converging with the regular digital domain of design. Via Imaging, you can take that “legacy” part, and get a 3D representation of it. How you use that data has been the question for over 10 years.

First, let’s talk about why your CAD or PLM system doesn’t understand 3D scan data. Now we see an apples-to-oranges problem: how do you take apples and make them into oranges? This presentation looks at the different generations of software trying to solve this dilemma. Closing with the latest generation, we see a way to take 3D Scan data, and make it work with our system, instead of outside of it. We look at a case study of a game controller, and how we can create everything from drawings to assemblies to tooling, just like a “real” part. The only difference being it wasn’t created in our PLM originally.

Monday May 17th, 8:30am-12:00PM

See how Reverse Engineering can be used, and get up to speed on the latest technology in the industry!

Since 1981 Rosenberg Ventilatoren GmbH (http://www.rosenberg-gmbh.com), located in Künzelsau-Gaisbach, has developed into an outstanding centre of the air movement and air handling industry by design and production of controllable external rotor motors. Rosenberg is a competitive medium sized company with around 1,400 employees worldwide and during the last 20 years, the Rosenberg Group has been complemented in Europe by several additional works in France, Italy, Hungary, Czech Republic and Germany.

With an annual production of about 120,000 fans, Rosenberg Ventilatoren GmbH currently exports 55% of the total company turnover and to keep the high quality of products, they aim to chase a continuous flow of information and good cooperation with their valued customers all the time. Furthermore, it is important to jointly achieve a continuous evolution of the quality of products.

The case study goes on to describe how they scan existing fan blades to generate CAD models.  And of course with XOR, the CAD models are editable because they have a full feature tree, with parent-child relationships (not just a bunch of imported surfaces):

As new project, they were looking for a solution provider who is able to measure a ventilator blade for qualified CAD modeling. The new project aims to create a precise CAD modeling for Highly-Effective Performance with lower noise and vibrations. It is always challenge for them to improve their products in terms of efficiency and noise and now they are quite keen to see new improvement with Rapidform XOR, the most comprehensive Scan-To-CAD application.

sigma3D (www.sigma3d.de), plays a role to serve the qualified CAD modeling using Rapidform XOR to Rosenberg Ventilatoren GmbH and Mr. Hubert Schwarz, Project Manager at Rosenberg is quite satisfied with the performance of Rapidform XOR. sigma3D uses a FARO laser scanarm for measuring, then imports it into Rapidform XOR to create a optimized polygon model in easy & quick way through “Mesh Buildup Wizard™”. This technology automatically processes the 3D scan data from multi-shot point clouds into a single qualified mesh. After that, to capture each geometry information interactively, Rapidform XOR is able to produce “Auto Segmentation” from the mesh model automatically based on feature region.

Of course, the real magic results come from what you do after you’ve gotten to a merged mesh.  The XOR technique of making CAD models for scan data is all about extracting design intent, then using real CAD tools (like extrude, revolve, loft, sweep, fillet, boolean and such) to build up a real CAD model that represents the scanned object.  This results in an “intelligent model”, meaning it’s feature-based and editable just like anything that can be designed in SolidWorks, Pro/E, NX, etc.  In the case of Rosenberg Ventilatoren’s fan blades, this means that they can improve upon an existing design and bring a new product to market in record time.

Using Split Face (found under Insert>Modeling Feature>Split Face), you can project a curve onto a face (surface or solid) and then trim or split that face.  But the projection method is different depending on whether you use 2D sketches or 3D sketches as your too entity to do the cutting. A 2D sketch will be projected normal to the plane that the sketch lies on, whereas a 3D sketch will be projected normal to the direction of the target face.

As you can see, using one or the other type of sketch will let you get the desired result depending on what you’re trying to do.

Using Split Face to create parting lines

1) Go to Insert>Modeling Feature>Split Face in XOR

2) Select the Silhouette radio button

3) Define the pull direction (this is the direction the mold will be pulled when separating).  In the example below, we’re going to use the axis of one of the cylinder features of this part, but you can use other reference geometries or features.

4) Pick the target entities that you want to split apart.  Since this is the split faces command, you’ll need to pick one or more faces here.

5) Click the check mark to run the command, and you’re done.

To summarize briefly: 3G RE is the process of making a full CAD model from 3D scan data, using well-established solid and surface modeling techniques. It’s the way RE is done using Rapidform XOR. Second generation (2G) RE is the process of creating NURBS surface models that are fit onto scan data (specifically, optimized polygon meshes of scanned objects). First generaration RE is the process of tracing over 3D scan data to build splines that you then use to make lofts and sweeps.

Obviously we strongly believe the third generation approach is the best in most cases of mechanical reverse engineering. If what you’re scanning is completely freeform or organic, the 2G approach is usually the best. That’s why we offer Rapidform XOS.