Hi Rogurt, is it possible for you to attach the actual 3DM file with your model in it instead of only screenshots? That would then make it possible to examine your model and also try the filleting over here - I can't really do any of those types of analysis on just a screenshot alone.

But one tip that may help - are these faces of the model all part of the same plane?



If so then deleting those pieces and replacing them with one single large plane may help - among the various things the filleter does not like is when you have a bunch of coplanar fragmented pieces like that instead of one big single plane for things that are all in the same plane.

- Michael