If I wanted to design something in small section WSF with a small zig-zag section in it to give extra flexibility and act like a tiny spring how much clearance would I need between the zig-zags to avoid them merging together?
I think it's about 0.7 or 0.6mm, but people have had success with 0.5mm.
I had something 0.4mm, and it fused, I did half expect it to, so it wasn't a problem.
I'd say stick to 0.7mm, and you should be fine, but see what others have to say.
I had success with 0.4mm (large ring spacing) and 0.22mm (small ring spacing) on my half persian 4 in 1 chain maille sampler - though there is some build up of material on the small rings where they would have been nearest whilst being printed.
I do think that successful non-fusing spacing also depends upon the shape of the seperated faces.