I've been trying to avoid stepping on landmines with MOI so I can get fillets to behave consistently but I feel like a blind man sometimes. This SEEMS like it should work. I built this shape up pretty slowly and checked these edges out as I went and all was OK ... until it wasn't. Basically, I can't get these edges to fillet:



Can someone look at this and tell me why the inner curves will fillet but the outer ones won't? I'm trying to get a handle on the rules.