Hi! The issue you are encountering is due to sloppy modeling practice. When you design in a 3D feature-based parametric solid modeling tool like Inventor, you need to make sure geometry is as precise as possible. Looking right does not cut it. Graphics in 3D can be elusive and deceiving. You need to make sure the dimension is correct. The curve is on the surface and the direction is intended.
I don't believe starting from scratch will help. You will run into more issues if you keep modeling like this. Attached is the part I modified so that the Sweep can be done. There are multiple issues with this model. 1. The 3D Sketch33 is not precisely on the surface. It is close but it is not there. I had to project the curve to the nearest point on the surface (3D Sketch34). The original profile in Sketch54 is not at the start and normal to the path (3D Sketch33). I created WorkPlane31 at the start of 3D Sketch34. Then I created Sketch55 and projected the geometry from Sketch54. I did not bother creating the profile since you can do that later. Lastly, I created Sweep Cut following the path and the guide surface. As you can see, the surface looks very smooth now.
Please feel free to ask any further question.
Many thanks!
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer