Creating a solid structure from a wireframe model 1

[Cradders]

Hello,

I'm using NX5.0.2, largely working on creating structures of struts. My work naturally includes working with wireframe representations of these structures (either created in an external programme or with NX's own sketch/3D curve functions). Is it possible to create a single, solid body from a wireframe model? Basically, an automated way of creating and uniting a set of extruded tubes?

For now, It is satisfactory to create these structures from cylindrical elements. The only way I can see doing this is manually - individually selecting each wire/curve to use with the 'tube' function.

Many thanks for any help,

James

 

[hudson888]

You could create a Grip or other VB/C language based program that allowed you to select several curves then would automate the process of creating individual tubes.

Apart from that I'm not sure whether you could find existing or set up a tube making wizard of sorts.

Best Regards

Hudson

 

[JohnRBaker]

James,

Could you provide a simple model or image showing what this 'framework' of curves looked like and what the final model might look like?


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

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[Cradders]

John:

I've attached an image of a representative structure, in wireframe and as a solid. To create the solid at the moment, I use a user defined feature that extrudes a tube, offsets the two circular faces by the radius of the tube and then blends the two edges. This creates a sausage-like element that ensures a complete spherical node is formed at each point where the elements meet. These are then united. If you have any ideas to speed up the process, that would be great! Either way, thanks for your help!

James


Hudson: I'll have a look for an existing wizard, I hadn't thought of that! Cheers, James

 

[hudson888]

James,

It looks a bit like a Mero structure that I worked on in the 80's, but all the elements are the same or almost the same. I wonder if you don't want to create this either with instanced geometry or with assemblies. Have a look into the Nx-5 instance feature function. you shouldn't need to remodel any two elements that are the same geometry.

Best Regards

Hudson

 

[Cradders]

Hudson,

Thanks for your prompt reply. I don't think an instancing tool is appropriate for my application - although yes, it is for the image I attached! I should have attached an image of a more complicated structure really. Suffice to say, the structures I am working on include elements of different lengths and irregular arrays.

Cheers,

James

PS: I've just looked up MERO - is this the architecture firm now called Novum? They've designed some pretty funky buildings!

 

[hudson888]

James,

Yes used to be Mero Schmidlin, a German company I think, and I guess that Novum have taken over that company more recently. We manufactured the structures under license for a project that was built in the 1980's. So it has been a while, but we had it in UG back then. The structure is tubes with threaded ends that screw into balls at the joints. The tubes were plasma welded where necessary, and the offcuts made great uprights for my carport. .

Anyway you don't look to have balls at the joints, so you'll need to cut out the ends to meet the other tubes at the joints. It does look like a good case for a customization as I said earlier. The beauty of Mero by comparison was that only the lengths of the tubes really varied much.

Best Regards

Hudson

 

[JohnRBaker]

James,

What is the typical diameter of one of these tubes as well their typical length (just so that I have some sort of 'scale' factor to work with)?

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

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[JohnRBaker]

Attached below is a GRIP program which will allow you to select as many line elements as you wish (up to a 1,000), specify a diameter, and it will create in one effort all of your 'tube' elements. That's the good news. The bad news is that you end up with lots of solid features and not everything is as associative as it should be. Also, you'll have to unite the finale set of 'tubes' into a single body if that is what your needs are.

Note that I've got a couple of ideas for improvements, but give this a try first and see if something like this will work for you.

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

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[Cradders]

John,

I've just had a look at the GRiP prgramme you've written. It's fantastic! It is almost exactly what I want!

I have noticed a few odd little glitches though. The first time I tried the programme, I wasn't able to view the created geometry in shaded mode, only in wireframe mode. Also, when I manually united a couple of the elements together, they disappeared from the wireframe view completely. I think the geometry is still there - if I render the scene everything appears present and solid.

**I just re-opened the part, and everything is there and solid, it's all good!

I haven't come across GRiP prgrammes before, they look like they could be the answer to many of my CAD relatd problems! I see you've generated tubes and spheres in the programme. I notice that I can only select straight lines with it. Does this have something to do with the generation of the spheres at the end points of the line? Would it be possible to edit the programme to be able to select curved lines as well?

I'd be interested to hear of your ideas for improvements. I think I will start to look for tutorials on how to make my own GRiP programmes too. Once again, many thanks for your help so far!

 

[JohnRBaker]

James,

Yes, I can modify it for non-lines. What other curve types, Arcs, Conics, Splines, would you need to support?

As for GRIP itself, don't get too enamored since it's basically 'obsolete' and while it is supported in the sense that programs written in it will continue to run on future releases, it is not being enhanced and many functions and capabilities added to interactive NX have never been and never will be added to GRIP. I use it because I've used it for 28 years and it's simple and easy to understand, but it has some severe limitation in it's architecture which is way it's been 'left behind' as it were. If you want to look at more modern approaches to programming, try journals and visual basic.

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

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[Cradders]

John,

Arcs, conics AND splines if possible! Do helixes come under conics? The ability to select helixes would be great, too. I'll start looking a VB then for programming these kinds of functions into NX.

Many thanks,

James