Double curved surfaces, help needed

allan_korup

Dear all

I am quit new to 3d modelling, and trying to get a hold on how to make double curved surfaces, and how to make the space between the solid. I hope these questions are not too dumb .... bare with me :-)
For a start I've made a lid for a rectangular canister. The top of this lid shall be smoothly rounded/curved from the top middle, out to all 4 edges, and the 4 corners rounded with a 3mm fillet.
The document is named Doublecurved_lid and is to be found publicly.

Question 1 : Loft_2Surfaces......Here I have made some curved lines on offset planes, and lofted 2 surfaces between them. On this I did not yet make the 3mm fillet in the corners, because I had difficulties getting the loft function to end the right place.
How do I make the space between the 2 surfaces solid ? 
I tried the thicken, and then split funktions, but there must be a shortcut to this....






Question 2 : Loft_Solid......Here I have made a solid loft function between the profiles. I worked out fine until I reached the end. How do I loft the last bit to the end, and out to the rounded corners ?







-any help appreciated !

Thanks

Allan

brucebartlett

I tried constructing the lid this way, see public doc

https://cad.onshape.com/documents/043c32ac948f922ba124a406/w/dcae101ab7c1793c4072c646/e/2e0cd78583ff062b43d5d528

The only bit I couldn't get to work was the loft to be symmetrical, so I ended up cutting in half and mirroring which is why you get the line down the middle. 
see V1 on history tree.


Then I tried this method, loft from the rectangular end, to center sketch with curved top, to rectangular end and add a top guide curve.

brucebartlett

I tried constructing the lid this way, see public doc

https://cad.onshape.com/documents/043c32ac948f922ba124a406/w/dcae101ab7c1793c4072c646/e/2e0cd78583ff062b43d5d528

The only bit I couldn't get to work was the loft to be symmetrical, so I ended up cutting in half and mirroring which is why you get the line down the middle. 
see V1 on history tree.


Then I tried this method, loft from the rectangular end, to center sketch with curved top, to rectangular end and add a top guide curve.

allan_korup

Hi Bruce

Thanks for your input. I learned a lot from this. I love the way Onshape and the community offers support :-)
One thing I'm missing though; I wanted the lid to be curved on the underside as well.
The top curves out to the outer limits, and the underside curves out to the "inner" limits.
Thickness of the lid is necessarily not the same everywhere, depending on the distance between the 2 curves made ( inner and outer ).
-hence my attempt to make 2 lofted surfaces and then fill the space between them.
Can you show an example on this ?

-all the best

/Allan