Hi Renato - it looks like you have done a previous fillet around the top edge of a pretty small radius, then did the boolean cut after that.

That previous tight fillet now makes a very tight area of edge curvature in the booleaned out piece.

Your next fillet radius will need to be even smaller than that previous one to fit.

A fillet basically needs to extend by a constant distance away from an edge.

So for example if you have an edge like this with the line being the distance you want:




That kind of situation is going to make the filleter try to produce something like this:




You can see all that bunched up and messed up area there - that kind of thing is going to cause problems.


In the case that you show there, I would recommend not doing that previous fillet before doing the boolean. Keep the top edges sharp, then do the boolean, then fillet all those edges including the top and around the boolean cut all at the same time instead of at different times, that should help out a lot.

- Michael