Hi,
I'm stuck at trying to shell a component, it will consistently give me poor results as in the image below, how can I amend this?
I create a solid from 3 sketches using loft, if I shell this solid it works fine. After two flexes however the above result can be seen.
Regards,
Peter
I removed all the flex, now it's just a simple lofted solid that I want to shell. It will allow shells of up to 0.9mm, but if I try to set it higher (1.5mm is what I want), it just gives me errors. Can someone please take a look?
If at all possible you'd probably have more success if you model the inner shape and then shell outward. But that's probably not a good method if you need to strictly control the outer shape.
Redo the loft and select Thin Feature, put in the thickness of 1.5mm and it should give you what you want. If the thickness goes outward instead of inward you can reverse the direction of the thin feature.
Peter,
I'm amazed that Shell worked after a single Flex. I am very hesitant to use Flex, except for something like showing a rubber or plastic part in a deformed position. I would try to build your shape without the Flex.
That type of shape is also liable to be a problem with Loft or Boundary, quite likely ending up with degenerate points at the ends. You might want to think about other ways to build it. Maybe Fill Surfaces used with helper surfaces to get your tangency/curvature continuity at the center lines.
Jerry S.
Hi Peter,
You are exceeding the min. curvature toward the front of your shape - i.e. min. is more that Shell can offset (you can see this if you turn on View>Display>Curvature and notice the very abrupt color change toward the nose of your shape; going from green to red band then very small dark spot.) As Jerry suggests, after your loft, create a split line across the front (sharp nose) in the the Front plane and then delete that face and put in a Fill. Now you can shell 1.2mm. Fortunately, Shell can deal better with offsetting the fill patch.
Mark
If LOFT creates all these problems, what's the correct way to build this kind of shape? Jerry Steiger wrote something above about fill surfaces and helper surfaces, but I don't understand.
Peter,
See if this link works:
Methods for creating a squashed egg
This is not the method that I was thinking of, but it might work well for your case. As I recall, Mark used a Sweep to generate the shape.
Another way to do it is to use Loft or Boundary to first form the shape, but then cut off the end that is causing problems. Use a Fill Surface to replace the end. The reason this helps is that two-sided Loft or Boundary Surfaces create degenerate points where all of the UV lines come together. The Fill Surface gets rid of the degeneracy.
The helper surfaces come in if you were to try and make the shape using just Fill Surfaces. I think you would need to have a surface on one of your center lines above that the Fill Surface could be tangent to. Then make the Fill Surface for the other side Curvature Continuous to your first Fill Surface.
Jerry S.
Hi Peter,
Yes, as Jerry mentions - sweep with guide curves would be a more robust surface than loft or fill.
Mark
