Today we heard about a great use case for reverse engineering from some Rapidform XOR users in Germany:

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.

If you’ve ever had to manufacture a really complex, organic shape, you may have wanted to split the model along a parting line for machining. Well, this can be a very tough job without a very powerful tool, plus a little guidance. Luckily, we are talking about Rapidform here, so “check” on the powerful tool. As for the guidance, here’s a tutorial that one of our favorite customers has used repeatedly to split some of the most difficult meshes out there.

By the way, this tutorial was written with the simplified RapidWorks interface in mind. That said, all the instructions here also apply to Rapidform XOR, but the commands may be in a different place than we describe here. Anyway, without further ado, here is our guide to trimming complex meshes…

Parting Lines 101:

How to Get Those Pesky Meshes to Trim

1. Run the Healing Wizard to get rid of all defects in the mesh. Optionally, run it a second time to
iron out any remaining defects.

2. Perform a Global Remesh, keeping the default settings. Check the box “Make clean and
manifold solid mesh” if the mesh encloses a volume (i.e. is not just a surface shell).

3. Accept the edits to the mesh at this point.

4. Create/edit a parting line as a 3D Mesh Sketch. Make sure the curve is a closed loop (indicated
by a red dot where the start and end points join together).

5. Rebuild the parting line with a very tight tolerance. Optionally, split the curve into several
smaller pieces and then rebuild all of them with a tighter tolerance. See the two pictures below:

6. Copy the mesh and paste it at the bottom of the Feature Tree. Edit this new copied mesh.

7. Try to trim the mesh using the “By Curve” method, and choose “Rearrange Poly-Vertices” at the
bottom of the command tool.

8. If this doesn’t work, or you get a message like the one below, you need to tighten the tolerance
on the parting line curve even more. Exit out of mesh-editing mode, then edit the 3D Mesh
Sketch of the parting line.

9. Select the whole parting line (i.e. all the segments that make up the closed loop). It’s time to try
some edits that will help the trim run smoothly:

– a. If you did not split the curve before, do so now by choosing the Split command with the
“Pick Points” option and clicking on several points around the curve.

– b. Double-check that the curve is closed by identifying a red point somewhere on the
curve.

– c. In the “Rebuild” tab at the top of the screen, make the allowable deviation (of the curve
from the mesh) smaller by a factor of 10. You should notice that the number of control
points increases drastically to meet the stricter tolerance.

Accept the changes to this 3D Mesh Sketch.

10. Edit the copied mesh again. Trimming should now work for you. If not, repeat steps 9 and 10
until it does trim well.

Choose both the inner and outer portions as “remaining regions,” and accept the command.

11. Choose the “Flood Fill” selection tool at the bottom left of the screen (i.e. the paint bucket).
Hide all meshes besides the one you are editing, and then click on one side of the active mesh.

When you have selected one half of the trimmed mesh using the Fill tool, hit Crl+C or select
Edit.Copy. Now accept the changes to the mesh and hit Ctrl+V or select Edit.Paste outside of
any mode to paste a new mesh into the Feature Tree. This new mesh is made up of only those
polyfaces that were selected before, so it is one half of our desired result.

12. Edit the complete, trimmed mesh once again. Choose the Flood Fill selection filter, and use it to
select the other half of the trimmed/split mesh. Copy this portion just as you did in step 12
above, then exit out of the mesh editing mode. Outside of any particular editing mode, paste
the selected polyfaces as a 2nd (or 3rd) new mesh in the Feature Tree. You now have both pieces
split along the same curve and saved as individual meshes. Save the RapidWorks project, export
your split meshes and continue with your overall workflow! Here is a shot of the final result:

Happy mold making!

The Rewrap Command (part 3)

We all know that the Rewrap command is useful for interpolating mesh data as well as smoothing noisy data. This post continues our look at the command with a third example. The first two examples can be found by visiting this post and this post.

Example #3

Generating a mesh for cross-sections: Generating cross-sections can be useful if you plan on creating lofts. Using 3d-sketch tools, you can smooth out and edit your cross-sections to create smoother loft surfaces.  Cross-sections can also be used to generate sweep paths, guide curves, and boundary-fit curves. What if your mesh is missing data? Or there are mesh features that you would like to omit from your final model? If each cross section was a 2d section we could use our sketch tools to fit geometry over the missing data. Or if they are 3d sketches, we manually could fill in the gaps with matched splines, and delete sections we don’t want. Of course, a much more elegant method would be to use the rewrap command.

In this example we have a Rapidform helmet. Most us application engineers in the company put these on to protect ourselves from the sales reps when the end of the fiscal year nears…

The scan itself is missing data and there a few features that we want to ignore during our modeling. With region groups, we can easily separate the areas of interests.

After deleting the unwanted data, or copying and pasting the regions of interest, we can run the rewrap command to simultaneously fill holes and defeature.

Now we can generate continuous cross-sections for Lofts…

for Boundary-Fit Surfaces…



or to help with Solid Modeling.

Final Thoughts
This concludes this 3-part series of Commands and Applications for the Rewrap command. Want to request the same for other commands? Have other questions or comments? Let us know in comments below!

Want a licensing walkthrough? Check out this post!

The Rewrap Command (part 2)

We all know that the Rewrap command is useful for interpolating mesh data as well as smoothing noisy data. This post continues our look at the command with a second example. The first example can be found by visiting this post.


Example #2

Autosurfacing a mesh for CAD operations: If you are creating an auto-surface of a model, it is usually said that a majority of the editing must be done to the mesh since you are creating a verbatim model. But with XOR, you have the added ability to create a hybrid model, that is, performing CAD operations on a verbatim model to create a model that has both the accuracy from the scan as well as the design intent of a designed model.

In this example, we have an autosurface of a bottom of a bottle. What if the scan of the bottom of the bottle isn’t flat? Well then our autosurface of the bottom of the bottle may not be flat either.

Using the rewrap command, we can extend the mesh in a natural way, create our autosurfaced solid model, then create a perfectly flat surface.

We can also change the height of the bottle by using a different cutting plane!

More Examples…

We’ll be posting the final example of how this command can be applied soon! If you missed the first example, check it out here!.