Trouble with Sweeping

 From:  coi (MARCO)
5789.7 In reply to 5789.4 

You can't change a corner point into a control point. You have to delete the corner point and eyeball your way along by adding control points.

...or you could use the REBUILD command, which reconstructs the given curve by sampling points and generating a new curve through those points. get rid of any corner points, use the #Points Mode. Uncheck 'Keep corners' and fiddle with the Point count to get a satisfying approximation of the original curve..pretty straight forward.

in this particular case (the gap thingy), there must be something special going on..