Surface Continuity 1

[ahv]

Hello,
Anyone please,
I build Section Surface type Fillet-Bridge.
I set it to G3 or G2 or G1. Surface join without an error.
I export it to software like Autodesk Alias or Rhino3D.
I have no even position match. I guess there is problem with tolerance settings.
But shape analysis "zebra" for example is perfect.
Please advise.
Thanks.
Anton

 

[JohnRBaker]

How did you 'export' your model to Alias or Rhino?

When you say 'join', are you Sewing the resulting surfaces?

You suspect tolerance problems. What do you have modeling tolerances set to?

Can you supply us with at least a picture of what you're trying to model?

And what version of NX are you using?

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.com/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[ahv]

Hello John,
Thank you for reply.

I use File>Export>IGES or STEP method.

When I said join, I mean NX did not generate an error with the max degree of 7 and 1 segment. I will send you some images.

I have tried to Sew the surfaces but it gives the same result after exporting. I will send you as well an image of exported file after Sew option. I can see that there are gaps. And the same time I think surfaces flows by G3 just they are not attached. This is why it has the gaps.

Actualy I am modeling nothing. I am learning the software and surface modeling. I saw some presentation of A Class surface modeling in NX so I am interested in quality surfaces.

NX version is 7.5.
Thanks.
Kind Regards,
Anton

 

[ahv]

Picture 02

 

[ahv]

Picture 03

 

[ahv]

Picture 04

 

[ahv]

Picture 05

 

[ahv]

Picture 06

 

[ahv]

Hello John,

I try to adjust the tolerance for "position" like it is in Alias ( the same value), NX asking me to up the degree so I do and I still have the gaps after export. And since I add degree. I have surface topology which does not match with original two surfaces.

I duplicate from first two NX surfaces the curves in Alias and I rebuilt the surfaces and joined them by Blend tool G3 (Flow). I have got single segment surface with the same degree like original curves and the same surfaces topology.

Thanks.
Kind Regards.

Anton

PS In 2D sketch module of NX I try to make constraint of a curve end coincident to a point on curve. When I zoom it in, I see the curve's end does not match there is a distance. Is it graphical representation or it is true?

 

[ahv]

Picture 02

 

[ahv]

Picture 03

 

[ahv]

Picture 04

 

[ahv]

Picture 05

 

[JohnRBaker]

After zooming up on any part of the model, do an 'Update Display' to see the actual curves.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.com/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[ahv]

Thanks John,
It works 'Update Display' for curves.
Kind Regards.
Anton

 

[ahv]

John,
For 'Update Display' is there an automatic display update somewhere in the settings?
Thanks

 

[JohnRBaker]

Not really. Sometimes, depending on the operation, an update may occur but there is no way to force the system to update after every operation or display change.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.com/museum/

To an Engineer, the glass is twice as big as it needs to be.

 

[ahv]

roger,
Thank you.

 

[Xwheelguy]

What units were used in the NX surfaces (mm or inch)?

If the units in NX are the same as in Alias, then you're modeling at a larger G0 tolerance in NX (0.0254) than you are in Alias (0.0005). See your screen captures where tolerances are shown - they do not match. The tolerance isn't going to magically get smaller via a translation is it? Unless I am missing something, these surfaces were made at 0.0254 and imported into Alias at 0.0005.

I would tend to think that the Alias tolerance should at minimum be 0.0254 if the tolerance units match. If that still showed a G0 discontinuity, then I would increase the Alias tolerance even more (0.03, 0.035, etc.).

Tim Flater
Senior Designer

 

[ahv]

Hello nkwheelguy,
Thanks for reply.
Both units are in mm. I try different kind of settings in Alias and in NX as well. Actually I think Alias oriented more to high value of tollerance for quality surface modeling than NX by default. Just I do not understand why I cannot get it higher in NX. Sometimes NX even asking to up degree when I make higher the tollerance. I do not understand why because minimum G0 gap has nothing common with surface flow. I mean in my case I give NX needed degree to build such transition with G3 or G2 value. How can I control transition surface topology? I mean that CVs match. It never offers same dregree surface and the blend is simple. I mean Section Surface tool.
Thanks
Kind Regards
Anton