Hi Alexander, so basically this model will need to be reconstructed to remove some of these problems - that extruded side piece will need to be constructed from a better initial curve so that it doesn't have those folded-over hooks at its ends.

Then once that part of the model is cleaner you may also try doing the shell first and applying the fillet after that.

- Michael

Michael, many thanks for your feedback.
I will have another go at re-modelling the part tomorrow.
Just out of interest could I create the same geometry with a different technique. The sides are rail sweeps and the top is an extrusion trimmed. I suspect there is an easier way to create the same part?

Thanks again Michael.
Alexander

Hi Alexander,

> I suspect there is an easier way to create the same part?

Well normally you want to try and let Fillet create the rounded corners, instead of trying to model the corners directly into your starting surfaces as you've done.

Check out these previous threads for some examples:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1002.1
http://moi3d.com/forum/index.php?webtag=MOI&msg=3137.1

You can use Sweep to build chunks of the model, but normally it's better if each surface gives only one element to the final shape, like one broad surface patch and doesn't have any tight bends in it - the sweep going through a tight bend is usually an indication that you're trying to combine more than one underlying form into a single surface instead of building them separately and then filleting them where they join.

Here's another example of that kind of thing of building some broader sheets of a model out of sweeps and then having a fillet provide a smooth juncture between them:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2164.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=2164.4

It tends to be hard to control things when you try to do too much of the model including tight bends and irregular boundaries all in one single surface.

- Michael