stl files

[danlamb]

Is there anyway of turning a Stl file into a Nx file in Nx so I can get measurements off the Stl file to build a new model?

Thank you.

Regards Daniel lamb.

 

[Karlis]

Hey danlamb,
I am no expert yet but I am also battling an STL file right now.
The problem with them is that there is no math involved in the STL geometry. It is simply meaningless a point cloud.
To turn it into a surface or solid body in NX you would require to reverse engineer it from scratch.
NX has some useful tools for this, the only one know how to use so far is "section analysys" that splits your stl file (facet body) into multiple sections and generates profile curve for each one of them.
You can then use these curves to recreate the body you need.
I hope someone else steps in here and gives a more direct hint, perhaps one that I can use myself

 

[danlamb]

Thank you Karlis how do you improve the quality of the stl?

 

[Karlis]

There are a bunch of tools under: edit/facet body
You can use command "subdivide" to increase the facet density or "decimate" to decrease it.
Some quite useful tools are "smooth" and "fill hole". I used these to fill in some missing points in a complex curvature.
NX did some outstanding work.

 

[cowski]

If you are using NX 9 or higher, the rough offset command will allow you to select a facet body and apply a zero offset. The result will probably be B-surfaces, but may be easier to work with than the facet body. It isn't a magic bullet, but the resulting section curves might be more useful.

Just remember the GIGO principle: garbage in - garbage out.

www.nxjournaling.com

 

[Toost]

This is a deep chapter...
A STL file can be imported into NX, it will there show up as a faceted body.
A facet body is composed of small triangular areas, facets. Each facet is flat. It might look smooth when shaded but it isn't.
If you section this you will get "millions" of linear "pieces", - One facet = "one linear piece".

It will show up as a shaded body but it should rather be considered a point cloud, it's the points which have been scanned/ measured and the areas between are simply interpolations.
You can if you like edit the display from shaded to "points" to see the cloud.

You can pick on the facets IF you turn on the "Point on face" snap type. (it's off by default) Thereby you can do quite a lot of things, such as draw splines on top of the facet body or measure.

You can split and merge point clouds in NX but you cannot manipulate the shape. Improving the quality is more or less impossible since we don't have the data, imagine measuring 4 points of a circle, in facet mode this would be rectangular. Improving could be some type of softening of the rectangle, but we would then get points in space without correlation to the original circle. - In animation software this is no problem but for reverse engineering it is.

There are a number of tools that can be used for reverse engineering, you can fit curves and sheets , you can draw splines on the facets, sectioning, the rapid surfacing etc etc.
as said, it is a deep chapter.


Regards,
Tomas

 

[kr7530]

Can anybody tell me what license(s) are required to utilize an .stl file beyond importing and sectioning?
The company I work for is investigating different options to be able to take full advantage of .stl file whether from simulation or white/blue light scanners.
We are currently working with our salesmen on this but if any of you could share your wisdom as to what tools are useful and hopefully the license that is required it would be a big help.
If it makes any difference my application is the sheetmetal stamping industry dealing with the morphing of surfaces and reverse engineering of components modified by hand.

Thanks,
Kevin
NX9.0

 

[TheeCircle]

Try using Rhino or Spaceclaim software. Rhino has excellent mesh repair tools.

They both have trial versions to try the software before making a purchase.

 

[Toost]

Rhino might have excellent mesh repair tools but i don't think that it excels in reverse engineering. NX has more tools for that.
I have not looked at Spaceclaim.
There are a few niche players on surfacing point clouds, The big name is geomagic, but what i have heard is that they are very expensive.

Regards,
Tomas

 

[TheeCircle]

Verisurf is great at reverse engineering.

 

[Toost]

Kevin, in my license, it's called "NX_Freeform_2".

Regards,
Tomas

 

[kr7530]

Thanks Tomas, I will look into it and some of the other softwares mentioned.

Regards,
Kevin