advanced surfacing: sweep tangent to a surface? 2

[opetrenko1]

Is it possible in UG to create a sweep tangent to a surface NOT at it's edge used as a guide, but tangent somewhere in the middle of surface?

Imagine a 3d curve and a deformed ball. sweep a line along the the curve tangent to the deformed ball.

I would imagine a variational sweep section element having a tangency constraint to a curve created by sectioning the surface.

Unfortunately, it seems only curves can be sectioning in such a way, thus providing with only points as reference.

Possibly, it's a limitation of UG engine.Then any workarounds, tricks, tips?
Thank you

 

[cowski]

Can you post a pic, or better yet, an example file of what you are trying to accomplish? If I understand your question correctly, I'll say that such a surface is within the capabilities of NX, but maybe not with the swept command.

An example file is worth a thousand words.

 

[opetrenko1]

Thank you.

here is very generic picture of the conept.

http://files.engineering.com/getfil...56-4846-bb9b-ac863edac2f2&file=SuperSweep.png

magenta guide of would-be "supersweep".
dark blue - section to be swept - is made of couple elements and is tangent to green surface. (I had to make a section (red) separately)

The real surface although distanly similar is not a body of revolution.

I see that what I want is essentially a floating guide, which is conceptually more complex then fixed guides that UG can deal with.

My be someone with surfacing experience can recommend workarounds, if UG enginge is incapable.

All I can think of is creating a bunch of sketches and throw a through curve mesh.

Anything better?

 

[JohnRBaker]

What version of NX are you running?

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

http://www.siemens.com/plm

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

 

[opetrenko1]

I run NX6,
but if needed can borrow NX8 licence from Siemens.
Thank you

 

[JohnRBaker]

The picture does not provide enough information to attempt an example. Could you upload either the part file in the picture, if that's not something proprietary, or something else which would show what you're looking for without 'giving away the farm'?

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.

 

[cowski]

Through curve mesh will probably give you the most control, but will probably also be the most 'high maintenance' option. A couple of alternatives to look at would be Bridge and Through Curves. both of these features will allow you to assign a tangency (or curvature) constraint based on an existing surface.

 

[opetrenko1]

http://files.engineering.com/getfil...4-8ca1-5c601acd7fa2&file=Eng_Tips_example.prt

John, cowski,
I greatly appreciate your invlovement.
the attached part is very generic. The farm is strict

 

[JohnRBaker]

We have a set of surfacing tools often which are often seen as useful for lofting, called 'Section Surfaces'. There are many schemes which attempt to replicate the approaches used when loftsman laid out shapes using conic templates or other methods in an attempt to get smooth transitions from one shape to the next while controlling the character of the transitioning shape.

Anyway, I decided to try one of these schemes found at...

Insert -> Mesh Surface -> Sections -> Section Fillet-Bridge...

The only assumption that I made was assuming the plane of tangency was the parallel to the plane of the your guide curve (Cyan Arc), so I created (Brown) Section Curve where your so-called section curve was tangent to the surface. Now since this surface function is a 'fillet' I needed a seconf surface so I created the extruded body (Brown) using the your guide curve as the profile. I then proceeded to create the Section Fillet-Bridge surface (Copper colored) using Tangent constraints. Now as you see it (see attached part), your 'section' curve (Blue) was NOT used at all as I depended on the two surfaces to provide the continuity. However, there is an option to use the shape a curve as a sort of 'template' to define what the shape of the surface is to be. To see how that would work (which BTW will give you, at least for the assumptions I made, the closet to what I think you want, at least mathematically, although I'll admit it's not going to be what you expected, trust me) double-click edit the Section surface (Copper colored) and when the dialog comes up, in the section of the dialog titled 'Section Control', change the Section Method from 'Continuity' to 'Inherit Shape' and then select your Section curve (Blue) and hit OK. Now I alluded to the fact that this is not exactly what I think you expected, but mathematically it meets all the criteria.

Anyway, play with this and some of the other Section surface schemes to see there might be something there that might help you get what you're looking for.

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.

 

[opetrenko1]

John,
Thank you! Will study your solution tomorrow thoroughly.

 

[opetrenko1]

John, cowski,
thank you!

section surfaces are definitely worth looking deeper into.

However, my intent was something like this:

http://files.engineering.com/getfil...8459a41e6532&file=Eng_Tips_example-JRB-OP.prt

http://files.engineering.com/getfil...ddc326dec20a&file=Eng_Tips_example-JRB-OP.png

unfortunately even in this simple case curve on surface gets out of tolerance easily, and an ugly surface is produced.

so the assumption about tangent edge is too strong. In this case I would use variational sweep since the second guide is defined.

 

[aksd]

Please see the attached file if it helps you out, i have just tried to make the surface by, thru curve mesh command defining tangency.

 

[mmauldin]

Attached are a few examples of different methods using various sketches, bridge curves, through curve meshes, section surfaces, etc.