Step Importing Issue

protontim

I have a STEP file that is not importing correctly. On import MECWAY is adding an additional face/surface that is not there. I have imported the STEP file into a second CAD program (not the one it was generated in) and it reads it fine (no extra surfaces). I also tried exporting the STEP file from the second CAD package and it still imports into MECWAY with the additional face/surface. The erroneous feature is shown in dark blue in the attached picture. Any ideas on how to keep this from happening?

Thanks.

Victor

Is this extra surface one triangle, and selecting it also selects a neighboring real surface? This isn't something I've seen before with the CAD import, but it's a bug that can happen occasionally with the automesher which is the same code, so it's possible that's happening here too.

In that case, I expect the surface to be absent from the mesh and not cause any downstream problems.

Otherwise, could you send me the step file to have a look at? You can use email if it's confidential.

protontim

Yes it is one triangle that also selects a neighboring real surface. When meshing, it gets all the way to generate the volume mesh (takes a long time to get there as there is a bit of complexity to the part) and then crashes. I'll tweak the meshing parameters and see if I can get it to work.

protontim

I can't seem to get it to mesh. Crashes appear to be because of "intersecting elements."

[Deleted User]

Just some general tips that may or may not help. I often have problems with iges, step, and sat files. Sometimes one format will work while another will not. You could try a different file format to see if it works. I have had file format troubles with Rhino and ANSYS. So those are not just because of Mecway.

Also, you may want to try and mesh it in Netgen. You have access to more settings in Netgen and can often get it to mesh when it fails in Mecway. However, that was as of Mecway v3. I haven't tried Mecway v4 yet.

Victor

You could set it to surface mesh only and see what it looks like. It might show this extra triangle or reveal another problem. Not sure how to solve it though, other than slightly changing dimensions of the CAD model.

Mecway 4 uses the same version of Netgen as Mecway 3, so your advice about that still applies, prop_design and it sounds like it would be helpful in this case.

Sergio

In Netgen there is a tool called IGS/STEP Doctor with a tolerance value that maybe could fixe this issue. Could be this feature included in further releases of Mecway?

Victor

Probably not without more requests because it's a more difficult job than calling the mesher.

VMH

Can the .step file be provided so we can take a look at it?