Fillet a lofted surface

[prettygoodnotbad]

I'm trying to fillet the top edges of this piece, it just keeps giving me the error message "can't be created at the requested size". I understand the loft shape might be hard for Fusion to figure out but I had made something really similar earlier and it was no problem adding fillet to all edges. I added the f3d below

[etfrench]

I can't tell you why the fillet failed on the upper lofted face.  It is possible to fillet it by first replacing the upper face with a planar face. 

1. Push/Pull the face .25".
2. Split the body using existing Plane2.
3. Delete or Remove the upper body.
4. Fillet the edges.

Is this the intended form?

[TrippyLighting]

Using a solid loft the way you do it creates a complex NURBS surface on the top.

The best way to design this is in the patch environment with surfaces.

You can change into the patch environment and simply delete the top surface.

Then use a patch to create a new top surface and stitch it. Then it's easy to fillet.

When lofting the entire structure the top surface will be a sort off swept surface with a relatively large number of NURBS control points that follow the outline of the rails. That creates a relatively dense quad mesh of NURBS control points that then has to mach well with the edge of the vertical surface. I am assuming that's where the problem arises.

When you delete the top and use a patch, that patch will be a trimmed NURBS surface that is a lot lighter and matches the edge better.

I'd have to use another CAD app to show you how this looks like.

In general, however, it is better to build this in the patch workspace.

[TrippyLighting]

Forget what I wrote above!

First of all, Fusion 360 should actually just fillet this. Period!

If you export this as a step file and re-import it the fillet works fine.

Secondly I had made the assumption that Fusion 360 creates a trimmed NURBS surface when you patch the surface, but that is not the case. It creates an even denser NURBS surface.

Here is the original loft with the NURBS control points show (in another app):

Here is one that was created by deleting the top surface an just using a patch it (Y.U.C.K!):

So the "correct" way to do this would be with an overbuilt surface and then trim manually. This surface is flat and only has 4 control points. 

[prettygoodnotbad]

I'm not sure what you mean by an "overbuilt surface trimmed manually" it sounds a bit like what @etfrench was suggesting by splitting the object with a plane, which actually worked. That said I'm still curious to see other solutions and also understand why this wasn't working in the first place, just to get a better understanding of what's happening. 

[kevster1]

To fillet the lofted surface you’re going to have to stitch all your bodies together first. Hope this helps 🙂

[davebYYPCU]

How much experience reading the older style interface?

How does your suggestion work?  There is just one solid body in the Browser.