Hi Wheel - this is an awesome result after only using MoI for 3 days and being new to NURBS modeling as well!

Some answers to your questions...

On this one:



That actually shouldn't be a problem - the fillet in that area is properly formed, just as a way to help some of its own internal calculations the filleter may sometimes split larger fillets into 2 pieces like that, but the shaping is properly formed there.

For example if I export to an .obj file, you can see that area looks fine:




This area here:



is not so well formed, but it is a very difficult type of corner situation to put a really great quality shape in. If you want a better shape, you kind of have to change the approach a bit so that the corner is not so severe there - that usually means placing a fillet on the protruding part first, before applying the fillet to where the pieces meet.

What I mean is say for example I want to fillet this object:



If I only try to fillet these edges here:



That creates a difficult corner situation:



It is tough to get something nice when there is a sharp-edged shape thrown into the mix there.

On the other hand, if you fillet these edges first:



That will create this type of shape:



Now that original place we wanted to fillet is traveling along a completely smooth path, a smooth path helps to make nicer corners:




Your other question on this piece:



Those narrow vertical pieces are not quite vertical, they have like a 1 degree angle or so to them, so they don't mate up completely nicely with the box below them.

If you want to build things by kind of carving or joining little pieces, it helps a lot more make sure there is a lot of accuracy and matching between the pieces. Things that are slightly angled or positioned slightly off will tend to cause little slivery bits to happen when they cut one another, those slivery bits will cause problems with filleting.

Let me know if you are still stuck on this piece and I can help you rebuild it if so.

- Michael