STEP 1 Extrude


STEP 2 Draw a line


STEP 3 Flow with your rail (don't miss the stretch option)



Is this what you want ?

Next delete the 2 solids done with extrude...

I think it's OK for your case because it's equivalent for an "only one profile sweep".
Not very orthodox, but the job is done.

In this case I solved it by temporarily connecting the two shapes:



And then cutting the connection after sweeping:



Incidentally this is similar to how it's gonna be printed, the 3D printer dislikes loose parts just as much as MoI does. :)

Hi Andre, was the problem that sweep "auto place" mode was being triggered when you didn't want it?

If so then another way to fix it would be to use Construct > Offset on your rail to make one that touches the profile to be swept like this:



In the future I want to add in some kind of control for sweep so you can tell it to do "auto place" or not explicitly, the current way it tries to detect it can have it turned on when it is not wanted like in your case here.

- Michael