Lots of ways to create the 3D curve. Here's what I did:
1. made a
plane where I wanted the centerline of the bead
2. started a
sketch in that plane
3. projected the edges of sheetmetal walls and bend into the sketch
4. trimmed the projected lines back to the length of the bead
5. exited the sketch
6. turned on the
Datum option
7.
projected the sketch onto the partbody of the sheetmetal part (with the Datum option on, this created a curve that was isolated)
8. turned off the
Datum option (so I don't forget to do it later)
9. added the
Bead based on this isolated curve
bead.jpg