Problem with shape made by curviloft

I’ve made two shapes with curviloft, one is inside the other and I want to user Outer Shell to make a single part but it doesnt work. I’m left with holes in the outside.

Any clues much appreciated.

shape 4.3 new outside attempt.skp (3.1 MB)

The two shapes are kind of weird together. Is that what you really want?

Screenshot - 12_17_2019 , 9_28_57 AM

If that’s really it, try scaling the model up by a factor of 1000x and see if that works better.

What is it really supposed to be?

Yes, that’s the shape I’m after but without the inside bits. It’s part of an ear trumpet. I’ve already scaled it up 10x but will try much bigger too. Thanks.

Generally for something like this I would just model it in millimeters as if they were meters.

Do you have a photo or something of this ear trumpet? I’m wondering if there isn’t a more straightforward way to model it in the first place.

The curve is a parabola and it’s important the shape doesn’t change. This is the view from the front.

So the inside is supposed to be a straight line as shown on the group I painted green?

No, Sorry I may have been confusing as the whole shape is the inside of the final part. So the left hand side is the red curve and the right hand side is the green.

I’ve made it this way essentially to try to solve another problem I had with curviloft so I’m going to rebuild the part from scratch at a much bigger scale to see if that helps. I may be some time!


I would make both the outside and inside forms into closed "solid " groups, and then subtract the inner from the outer with the Solid tools. But as Dave’s screenshot shows, currently the shapes intersect when combined.

I don’t think subtract will work as I want half of one shape and half of the other. Outer shell should do it but didn’t work. **Cheers.


Rebuilding the part at large scale made it possible to split the part horizontally then use Loft along two paths to make the top and bottom seperately without the need to merge two parts.

Thanks for all the help