Closing volume as per V4

[windsurferm]

Ladies and Gents,

Have frustrated myself half to death today trying to close a volume ( as it would have been in V4 ). How do you create a solid from surface data, from Alias in this case, so that I can do boolean operations on it. It is a sym op component with an open lower face, so have created a closing face, but that is as far as I seem capable to get.

Someone please help the mouse and my hair has taken a real beating.

 

[Azrael]

Join the surfaces in GSD before using the close surface feature in part designer

 

[windsurferm]

Have tried that route and am getting errors or gaps in the surface, but it has come out of ALIAS, so would assume that these are pretty much perfect a class surfaces.

 

[catiajim]

Sorry to disappoint you, but ALIAS is NOT a Class A surfacing package! Nor does it translate very well into CATIA.

ALIAS is a good rendering system, but as any of the Class A gurus around here will tell you, it's Class B at best.

 

[jormah01]

Try to increase the gap value on the Join function in GSD.
This works some times for me when I do Iges imports because the Close function in Part Design is more sensitive about gaps than the Join function.

 

[Azrael]

Like "jormah01" says, increase the the gap value on the Join function and use healing before Closing it.

 

[onyx01]

I agree with Azreal and jormah01, increse the gap value on the joim function. In most cases you will have to replace some surfaces which will not "close". The surfaces you create will be better than the ones imported from Alias.

Brandon Jacobsen
Product Design Engineer - Catia

 

[windsurferm]

Ok part is healed, and seemed to heal fine giving me not problems, but am still getting the following message:

Close operator: an opening in the selected body cannot be closed by one single planar face. Modify the part.

And yet when I create a face to close the part it would appear that it is a planar gap left open. Am I missing something obvious or are the surfaces just bad?

 

[onyx01]

I had similar issues when first dealing with closing surface models. What I learned, and it took a few times to bang it in my head, is when you "JOIN" the surfaces, check the preview, it will place colored boundaries (in my case Green) around faces which have gaps to adjoining surfaces. In many cases even when I loosened the tolerance I would see the green boundaries. One other thing I learned is this will choose double surfaces (surface on surface), which will not allow you to close the open body.

When I would eliminate most of the boundaries, I choose to "HEAL" the geometry, and at times it would not heal properly. When HEAL failed to work or JOIN for that matter, I would remake surfaces. On one occasion I made 1/3 of the parts surfaces in V5 to close the part.

It's a tedious task, however talk to some Pro/E people and they will tell you horror stories about making solids from import data. I was one of them, and V5 is a dream when it comes to something like this.

I should have taken better notes when discovering this process so I can share with the community. Unless someone has an if/then procedure it's trial-and-error.

Brandon Jacobsen
Product Design Engineer - Catia

 

[tpale]

Hello,
I think that it's never ending story how to close surfaces to solid. But here is couple tips, see the CATIA Data Exchange Interfaces Manual in Infrastructure section. There is IGES Trouble Shooting and Best Practices chapters. They have very good procedures to fix models.

Then in Join You should use in Angular Treshold field 179deg in order to avoid dublicate surfaces.
Merging distance should be little bigger than user intendet resolution field in igs-file.
In stead of selecting all surfaces from the tree, select just one surface and use G0 under RMB.
Fast way to detect if there is holes in the join, use boundary command. If the holes are in non critical area You can just use fill to that boudary (not very nice quality but ...)
BR. TPale