Hi Oskar, could you post a 3DM model file with your current attempt at doing it with Blend?

Seeing that would also probably help to understand your sketch better - you mention a smooth transition between the cube and the main body, but in your sketch it looks like there are mostly sharp transitions there? Is it only at the top that it should be smooth?

It may be possible that you would want to model an initially larger more simple smooth piece, something like this:



Then use booleans to cut it and remove pieces you don't want, like this:








That kind of workflow of "build it simple and larger/extended initially and then cut back" is frequently used in NURBS modeling but it is rarely used in polygon modeling so that can take a while to get used to this different technique if you come from a polygon modeling background.

If you are using Blend from the beginning it probably means you are trying to build things in a kind of "patch by patch" method instead of utilizing larger simple pieces and cutting... That can be ok for certain kinds of things but it is more general that you would want to try to do more of the "cut things out from a larger smooth form" type thing.

In NURBS booleans should be more of the first way you try to build things, rather than something that you would avoid like in a polygon modeler.

If you can post some model files of your current attempts it would help to understand what you are trying to do a lot better though.

- Michael