topic Re: Creating a surface loft between two curved edges/surfaces in Fusion Design, Validate & Document Forum

Creating a surface loft between two curved edges/surfaces

don.ostergard — Fri, 16 Jan 2026 07:02:20 GMT

Evening all;

New to the forum but I have been using Fusion 360 personal for a couple years now. Mostly to design parts for various automotive items I am needing to work out for prototyping. I am learning every time I get into Fusion so I am pretty sure I have done a pile of my current design incorrectly to get where I am now.

Essentially, I am designing a multi curved side window for my buddy's custom car project. I have the main window piece designed now but what I am trying to do now is join a few curved surfaces so that the original "outer surface that fits to the inner car body mates up with the inner, more curved side window.

I have been searching online as well as through this forum but cannot find a method to join the two edges. Surface loft or soldid loft both don't work for me. Trie dpatching as well but know very little about that function.

Pic below shows that base final side window with the two curves.

Took way more fenangling than I think it should have due to my skill level, but I am happy with what is there at this point.

Per the pic below, I am now trying to connect the empty space between the outside surface I created, which represents the out surface of the body part and the curved window rear area. The window curves in after the B Pillar and will end up with an air intake coming off the back end of the window. I need to fill in the space between the body panel and the rear window section to close off the empty space between the body panel and the window rear section.

Could someone please point me to a good video or show me the steps to do that operation? I appreciate that someone with way better skills than I just do it and tisk tisk my method of getting to here while they are at it... :), but I would really appreciate learning how to do this type of operation at the same time. Pretty sure won't be my last body panel filling need during prototyping.

My fusion file attached as well to help. Again, not very good at this so I am very sure I could have made to where I am way more easily than I have.....

Thanks very much

Don

Re: Creating a surface loft between two curved edges/surfaces

16goulde — Sun, 18 Jan 2026 18:55:32 GMT

Hi Don,

I'm not that experienced in Fusion and I don't think I understood your request, but I thought I might as well give it a go. Is either of these (see pictures below) what you're looking for? The first one is a surface loft to the outside of the outer surface and the second is a surface loft to the inside of the outside surface. In both of them it's just a surface body but I suppose you could use thicken or other tools to change that.

If this is what you need, then here's how I made them:

First I created a plane at an angle through an edge on the solid body:

Then I split the face of the outside body with the plane I just created.

This also splits the edge of the outside surface, so that when you do the surface loft it will only select the edge up to where the solid body meets the outside surface, and no further.

Let me know if this helps,

Emily

Re: Creating a surface loft between two curved edges/surfaces

don.ostergard — Mon, 19 Jan 2026 16:45:38 GMT

Emily

Thank you very much for this. The first image is exactly what I have been try to do. Excellent. I will give this a shot. Much appreciated.

As an addition, after typing the first post, I tried the same approach as Emily but created a plane on the z axis and projected the outer surface to that plane. I then used offset for a 3 mm external offset. Closed the offset off to create a connected surface. Extruded the surface out to past the inside body. Then tried to split that surface with both inner and outer bodies to essentially do the same operation as Emily did to get that surface. I ended up with an error saying the splitting surface did not intersect the body being split.

No idea how to fix that error but hopefully I can recreate Emily's response to give me my new surface.

Thank you

Don

Re: Creating a surface loft between two curved edges/surfaces

don.ostergard — Tue, 20 Jan 2026 01:55:17 GMT

Emily;

Again, I appreciate your reply and explanation, but I cannot seem to replicate your process and I am getting errors. Would you be able to upload an export of your Fusion file and attach here please? You have done exactly what I want to do but I cannot seem to figure out the angle plane and face split.

Very much appreciated for your help.
Don

Re: Creating a surface loft between two curved edges/surfaces

16goulde — Tue, 20 Jan 2026 20:14:14 GMT

Hi Don,

Here is my Fusion file - I hope it helps.

Re: Creating a surface loft between two curved edges/surfaces

don.ostergard — Wed, 21 Jan 2026 00:00:42 GMT

AH OK. I see what I was doing wrong with my plane now. Again, exactly what I was trying to do and you have helped so much.

Thank you very much for the help