Tried to create the model again but wasn't able to make it a Flat-Pattern:
1.) Revolve in modeling to create the arc...
2.) Extrude to cut hole...
3.) Then I tried to turn to sheet metal and turn to Flat-Pattern
- But errors in bendings ?
Try to create the model directly in the sheet metal application using contour flange and normal cutout as below, then your flat pattern will work.
Which is created first the Arc or the "Fish fins" ?
- The 1st Base contour flange includes what sketch ?
- and the 2nd contour flange includes what sketch ?
I cheated a bit and created it angular...?