Shell problem

 From:  Michael Gibson
4824.7 In reply to 4824.1 
Here I have separated and untrimmed both pieces so you can see the gap between them:

The other side seems to be touching though, so maybe something was at a slight angle when it was constructed.

One way to fix that gap would be to turn on surface control points and select the line of control points down the middle and collapse them together with flat snap using the edit frame.

But even after that it will be a difficult piece for offset or shell in MoI to handle, because of the sudden change in shape and bunched up curvature in the surface right near this tip area:

Stuff that changes shape and curvature a lot in such a small area tends to be difficult for surface offsetting to handle, it tries to make a result that tracks along the surface normal and the surface normal is changing rapidly in that small area.

To have the best chance of getting a good offset you usually don't want to have a collapsed down and pinched kind of shape like that - it's better to have a more evenly shaped surface that's been trimmed to make it have a 3-sided outline - directly surfacing a 3 sided shape that has different lengths along each side tends to produce that kind of pinching near the tip.

- Michael