Hi Jurgen,

> I was able to apply a .2 Fillet to your 'KleinTeil clipped',
> but I was not able to separate the 'desired object' from
> the 'border' cut away, i.e. I could not DELETE the 'border'.

Hmm, yeah at some point it was working but not after I saved and reloaded the model.

When you get a fillet that has this odd border thing in it, it means that the filleter was able to generate fillet surfaces but it ran into some kind of error when trying to trim the main object when cutting it with the fillet surfaces. It returns the generated surfaces in this case so that you may have a chance to do some work on things to salvage them.

It seems to be having some additional difficulty in this area of the model here:



It's actually not so good for filleting when both sides of the edge are curved surfaces to have edges join to a common point like that, because fillets work by a kind of surface offset and that means that one fillet goes like this:



And the other fillet goes like this:



So that leaves a kind of gap area between the fillets that the filleter has to deal with filling in, and the filleting engine seems to have some difficulty handling areas like that.

If you zoom in on this area of the fillet surfaces you will see a kind of problem area:





It's possible that if that connection piece is repaired (like maybe just deleted and a loft put in between the ends of the other longer fillet pieces), that it could then be used to trim the main object succesfully with the Trim command to incorporate the fillet into the main object.

- Michael