Shell problem

[cubalibre000]

Hi,
I attach a Parasolid part.
I can't shell.
I would like to shell as the image of 2 mm.
Exist a tool or something to understand where the shell fails ?

Thank you..

Thank you...

Using NX7.0 and TC8.1

 

[jerry1423]

There is something wrong with the body.
It looks like what you wanted to be subtracted out was not subtracted out. I did a "join Face" and all the faces went together and became a simple block.
You should be able to do the shell after you figure out what went wrong with the subtraction.

 

[edgray]

Are the sides of the object with the "extra" edges supposed to the have those "extra" edges? If you remove those edges as mentioned above (I used replace face) I got a successful shell. Actually I got it to shell anyway I am working in NX5. I posted it back

 

[JohnRBaker]

What it looks like is a solid model which was only partially processed by a Parasolid operation.

There is a procedure in PS where you 'imprint' a set of edges on the face of a solid. This occures often in PS and is the equivalent of a 'Divide Face' operation in NX, but in PS it's most often just one of severals steps taken in order to produce a new model, such as when performing a 'Shell' operation or even a Boolean.

For a Boolean subtract, PS will first compute all the face-face intersections, then perform an 'imprint' on the faces of the model using these intersection curves, then it will identify and delete the unneeded faces and then 'glues' the rest of them together, after which it will label the results a 'solid' if it forms a 'water-tight' body or a 'sheet' if it does not.

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.org/museum/

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

 

[hudson888]

I'm wondering what the problem was. I just shelled the Parasolid at my first attempt. I have attached the file.

However I suspect that you may have wanted something else which I will attach in a separate post.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[hudson888]

This second one shells the body twice to create faces normal to that wound line that was shown. If this is your intent then what you seem to forget in your initial approach may be that there are no faces perpendicular to the edges on on the surface of what are two coincident faces spanning the wounds.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[cubalibre000]

Hi edgray,
what you have done it's not what I would obtain.
Please see my attached image.


Thank you...

Using NX7.0 and TC8.1

 

[cubalibre000]

Hi Hudson,
your second solution permit me to shell the part, but as the image that I attach...two face aren't perpendicular.
I tried after your solution divide the face and add draft or use the ST command, but I can't do it.
For the dx face it's possible with divide face, but the left I can't.
Have you some suggestions ?

Thank you...

Thank you...

Using NX7.0 and TC8.1

 

[hudson888]

Well of course it isn't perpendicular there was no reason given to assume that it would be. However if you simply thicken the faces based upon the original then you do get perpendicular faces. The downside would be those necessarily nasty looking conditions in the corners where the faces cannot be continuous.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[cubalibre000]

Hi Hudson,
the result it's correct.
Te only question is :
Add thickness to faces or shell, why don't produce the same result ?
I think that the thickness command make offset face, trim together and produce a closed volume.
The shell command make offset face, trim together produce a closed volume and subtract with a boolean command to the original body.
It appear identical, but as we can see the result it's different.

Have you some comment ?

Thank you...

Using NX7.0 and TC8.1

 

[JohnRBaker]

Because Shell is NOT the same as Thicken and never was intended to be. Thicken creates totally different topology using totally different tools. Granted, if the original part has only 90° corners, the results will be the same, but once the corners are no longer 'square' the results will be different.

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.org/museum/

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

 

[hudson888]

They are two different tools specifically intended to create slightly different results. If you were to think of how you otherwise might build similar geometry then you can describe the results. The shell effectively references the outside faces and offsets those inwards then trims and subtracts the result. The thicken effectively offsets the selected faces, creates ruled surfaces between the adjacent edges and then sews that output.

Best Regards

Hudson

www.jamb.com.au

Nil Desperandum illegitimi non carborundum

 

[cubalibre000]

Thank you to all...

Thank you...

Using NX7.0 and TC8.1