Hi Lang - re: fillet - because your central hub piece is not a closed solid and is an open surface with the ends actually being different lengths:



That kind of situation is making it difficult for the filleter to figure out how it should trim off the ends of the fillet surface that is constructed. So instead of any trimming you just get the full extended fillet surface.

If you wanted the fillet to be automatically trimmed, you could try to make the box to be a fully closed solid instead of just some open surfaces, that will help it to know how to cut the fillet with some of the side wall surfaces.

But probably the easiest thing to do is to just trim the fillet that was generated to whatever you need - the just newly released V3 beta actually as a Trim by Isocurve option which is handy for just this type of situation. To use it, use Edit > Separate on your fillet to break it out so that it's just a single surface all by itself and not joined to anything else. Then select it and run Edit > Trim , then push the Isocurve button and you will then be able to pick a point on the surface and you will see some lines across the surface to use as cutters, switch the direction to U or V to get the particular cutter line that you need. I'm not exactly sure how you want the result to be formed since the ends are not aligned, that's up to you to decide where to place the cut.

So basically the fillet that you see there has generated the raw extended material that you need and you can then trim it to cut it down to be smaller.

- Michael