Fusion
that is a pretty messy mesh. I would start by cleaning up that mesh. You might be able to do it in Fusion, but, personally, I would use Meshmixer for that. Trim off the unneeded bits, clean up any holes, etc. Then, I would follow the recommendation by @TrippyLighting here: how-to-work-with-irregular-and-organic-stl-files , which uses InstantMeshes to convert a triangle mesh to a quad mesh. Then, bring that result back into Fusion (with triangulation turned off), and you can convert it to a T-Splines (Form) body, which can then be easily modified.
Jeff Strater
Engineering Director
What is your level of experience with CAD & 3D modeling ?
I would likely use a surfacing workflow to replicate the geometry of this object, but that is certainly not a beginner task!
However is is also quite possible the the quality of the outcome does not need to meet the quality requirements I have for my own work. As such a bit more detail about the intended end use would help determining a feasible workflow.
@Anonymous wrote:
Understand...
The mesh is really dense and Fusion can handle up to 10 thousand triangles...
I'm getting really bad performance in my workstation trying to reduce the size of this mesh...
The 10k polygon limitation only applies when you want to convert the mesh directly to a BRep. That would likely make no sense!
In general, the approach you are taking by creating the mesh section sketches is OK.
However, my recommendation would be not to try yo use these directly as input to loft geometry, because the curvature of such curves is terrible and is likely going to lead not only to bad surfaces, but modeling problems later on.
What experience with CAD and surface modeling do you have ?
I would not consider this a beginner problem! to do this properly you need to have a pretty good understanding of surfacing techniques.
What changes to the shape do you want to make ?
As others have already noted, this mesh file is dense and pretty large in file size, so loading the Fusion 360 file might take a while. I'd play around with reducing it until you start loosing detail and then use the result for mesh section sketches and as a visual guideline.