apparently, if non planar straight lines are filleted, it works, but if there is a smooth curve involved, the fillet tool does not work. 2 straight lines in a crooked angle are still planar, I realize now, even if they are not parallel with x, y or z.

extrude -> fillet -> select edge -> copy -> paste

that's a nice one (and fast too!), Max! thanks.

wim

Hi Wim, yes for curve filleting the curves need to be coplanar. And like you figured out, they can be on any oriented plane not just ones aligned to an XYZ axis.

- Michael