How to unite a sheet body with a solid

[jonmwilson]

I am have set of surfaces and have sewn them together but for some reason am having trouble uniting these with a solid body. I have done this in the past but don't understand what I am missing in this case. I've attached the model to help show what I am talking about. Thanks.

 

[mmauldin]

I don't know why your model doesn't work, but I changed the .001 dim in sketch_003 to .005, used bounded planes for the end caps and reset the mesh tolerance to 1/10 of their original values and it works. Maybe some clues in there somewhere.

 

[Cid1979]

Jon,

Your trouble is that the blue portion is still a sheet body, if you use examine geometry under your analysis, you can see what the problem is, I have done it and took a picture of it so please give it a try and you will see where it is giving you troubles.

Thanks

CID

 

[SiW979]

I mananged to turn it into a solid, but it doesn't like being united for some reason.

Best regards

Simon NX7.5.3 - TC 8 www.jcb.com

 

[mmauldin]

I went back and saw that my unite didn't work very either. The problem seems to be that the default modeling tolerance was equal to the .001 gap in "SKETCH_003". I changed the default modeling tolerance to .0001, reset the .005 dim I had in "SKETCH_003" to the original .001, changed the "Through Curves(4)" tolerance to .0001. Then I recreated bounded plane and the unite and it works.

 

[SiW979]

I changed the gap a bit and used surfaces for the whole thing with this version and it works a lot better.



Best regards

Simon NX7.5.3 - TC 8 www.jcb.com

 

[jonmwilson]

Thanks for all the help. I was able to get it to unite with your suggestions. It seems the small gap was the root of most of my problems for some reason.

 

[DaSalo]

It looks to me like a conflict with the feature tolerances and the nearly non-manifold shape of the model. If the inner corners of the v-shaped groove touch then it becomes a non-manifold solid (you have an edge that is shared by more than 2 surfaces.)

Because the gap between the corners is so close to the modelling tolerance the system is trying to sew the corners together. Unfortunately, when the corners sew together it creates a non-manifold solid so the sew then fails to create a solid body from the sheet bodies even though they do fully enclose a volume.

There are many ways around this but basically you either need to make your gap wider and close is up again after everything is solid or you need to adjust tolerances until you find a combination that prevents the system from sewing those corners together in the first place.

I try to avoid adjusting tolerances if I can as this just gets confusing and it can be hard for others to track what is happening. I would just adjust the sketches to create a larger gap, get it all sewn together, and then use "Move Face" to close the gap up. You could also model the whole thing without the V-groove and then sweep a profile to cut that out at the end. That way might represent your design intent a bit better as you would be able to directly dimension the gap in the sketch of your tool solid.

On a side note, your bottom sketch is not symmetrical about the datum CSYS as it looks like it was intended to be. Instead of sketching that entire lower profile you could simply sketch half of the whatever is the functional side of this thing and then use offset and mirror to complete the shape. This way you know everything will stay even and symmetrical.

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