Need help modelling and controlling curves on ring.

[dangartland]

I am having trouble modelling a ring whilst being able to edit certain features later on, specifically the top curve shown in this sketch.

I have modelled it using a split body workflow but cant seem to get a good control over the curvature.

The side profile has also been distorted

I tried to build this with splines but the section refused to sweep via spline rails, So I instead built a guide using the split body tool.

But now I have no way of controlling the curve I want to control. Can someone suggest a way I can better build this to have more control over the shape in fusion.

Many thanks,

[jeff_strater]

There are likely many ways to do this.  I like your surfacing approach.  A couple of suggestions:

1. this thing appears to be symmetric.  Just model half of it, and mirror at the end
2. instead of a cylinder in the surfacing approach, use a loft from a smaller circle to a larger one, to get your "top curve" that is closer to what you want.

[TrippyLighting]

Can you share the model ?

[TrippyLighting · Accepted solution]

The geometry you have sketched in three views is geometrically impossible to create in a true 3D model.

You'll have to make compromises 

[dangartland]

Thanks for this it definitely helped, I understand that the geometry is impossible and so I wanted to make a model wherein I can edit the curvature to match as close as possible to the top view of the sketch.

[dangartland]

Thanks for the help ill give it a go