Hi mir4ea,

re: attachment tmp3.3dm - that's an even more significant example of trying to do too many shape changes in one single surfacing operation...

You've got to break things down into smaller components than that, probably something like a base rail revolve to make main shape, some indented areas probably done by booleaning away some swept shapes and then doing fillets to smooth out the cuts.

When using a surfacing command, the surface that is generated should be more of one single common element throughout the form, if you have tight bends in it, that's usually where you should be having fillets or blends between 2 different broadly shaped surfaces instead of trying to build it in one single surface creation command.

- Michael