Hi Warren,

> OK, thanks for the info. I downloaded the ViaCAD demo version and the interface is ... challenged,
> I guess is the way to put it. Every time I have to use it, I predict I will be irritated. :P

It's not so bad if you use it just for filleting, that just involves picking edges.

It's filleter is significantly better at handling more complex corner cases.


> So is there a best practices for Filleting thread somewhere that I could read through
> or is it just an experience thing?

There are so many different kinds of things there isn't really just one thread that covers every kind of geometry, it somewhat depends on the particular shapes that you are dealing with.

In the future I would like to try and license one of these other geometry libraries that has more sophisticated filleting to help out with this.

Some general things to avoid - it can help to have more simple edge topology with fewer edges coming together all at one single point. Also having things meet up at a very shallow angle can make things more difficult, it's usually best for shapes to be more distinctly sharp to one another or more fully smooth to one another.

Sometimes doing an initial larger radius fillet to smooth out one area of the model can then help to make the fillet generation easier in the original area - surfaces that are smooth to one another are easier to fillet because the fillet surfaces meet up directly and don't have as difficult of a corner juncture to have to be figured out.

Like for example in your case here, rounding off this edge here with a larger radius:





Will then make this area actually easier to fillet after that:






Another area to watch out for is fillets can easily fail if they just don't fit within the given area, especially when things are at sharp angles to one another fillets will want to eat away a lot of space and if they try to eat away an entire face or edge that will cause them to fail too.

Filleting is definitely a finicky area in MoI, it's a lot harder problem than what it might seem like to get different kinds of corner junctures handled well.

- Michael