Hi Anis,

> You can try fillet with "const dist" option on attached 3dm.

Thanks - I can repeat the failure when doing the edge-based fillet after assembling those pieces into a solid, but if you do a surface/surface fillet on the original pieces you have it seems to work ok.

The way you have that file structured currently with separate surfaces, it is actually faster in this case to do a surface/surface fillet anyway, your surfaces will be all ready to join immediately after the fillet that way.

A surface/surface fillet is when you select 2 individual surfaces (which is actually how you have the file arranged at the moment), and then run Fillet, rather than selecting pieces like edges of a joined-together object.

Surface/surface fillets can succeed in places where the edge-based ones may fail.

Here is a quick demo of getting a constant distance fillet on your file by using surface/surface fillet:



- Michael