A challenge for the fillet experts

In the attached model, there is supposed to be a radius 5 fillet between the conical base and the “spool” at the top (note: the model is already scaled up to meters to avoid small faces). How would you go about generating that fillet?

part 303.skp (100.7 KB)

Something like this?

How are you going to use it? It would be easier to deal with if your circles and curves were modeled with more sides.

FWIW, I drew a quarter of the fillet using Curviloft.

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Just a drawing exercise, no particular use. How did you set up the boundaries for curviloft?

Before doing anything I ran Eneroth Autoweld on your geometry so I could easily select and copy the seam line out of it. Then I drew the arcs so I could create a quarter of the fillet. That fillet geometry was copied and flipped to make the other three quarters.

If I were going to model this thing to be used by itself I would use a lot more segments which would make it easier to get a smooth fillet. That’s what I did for the similar fillets in these.


Yeah. I had just done a model where I used way too many arc segments and was a bit gun shy on this one.

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Got interrupted by FIRST Robotics. Here’s another version.

part 303.skp (1.5 MB)


I so admire work done with the fillets in the sample file and the other examples. The fillets blend flawlessly with the adjacent surfaces.

I tried reproducing this with some success but when I went back to trace my steps again, I run into surface border issues with curviloft skinning. I created three paths and the faces to define a quadrant of the fillet. When I select these items and run curviloft, I get the surface border messages with Solid Inspector. Sometimes the number of surface borders varies, perhaps based on my selections with curviloft. I have attached the file with the quadrant copied out as a component. Any ideas to avoid the surface border issues?
Also attached some screen shots showing the parameters used when running curviloft.
Thanks in advance.

part 303-8.skp (1.1 MB)

I don’t bother making the fillet geometry a solid. I only make the outer surface.

part 303-8.skp (1.3 MB)

That makes sense since these outer surfaces get mirrored and pasted together to form the final solid component.
Seems like I have been doing extra work. Once again, Dave to the rescue. Thanks so much.

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One last question on the filleting. I made the solid component merging the geometry of the cone, the fillets and the top. Then I soften the edges between top and bottom of the fillets. (see attached model)
As I orbit underneath the model right above the fillets I notice some faint white triangles which appear more noticeable than on your model (from your post on Dec 21st). Is this something that can be corrected or is this nothing to be concerned about ?

part 303-9.skp (1.2 MB)

I’m not seeing anything strange about the geometry. I wonder if it’s a graphics card thing.

Thanks for checking. It is a minor difference but I did one earlier that was more like your model with almost undetectable view of these triangles. Thought maybe it had someting to do with the order of when I made the lines softened. Both models look good in Layout.