Problem Creating a Bow Shape

In the attached file, I have a first pass at creating a bow shape. I have picked four curves to form an edge such that none of the curve are tangent.

I’ve done some fairing. Probably more needs to be done. I Probably do not need all the curves to define the shape.

The problem I am trying to tackle at the moment is this bump that forms along the 2d from the top frame when I do a networksrf. If I omit the 2d frame in the networksrf, the bump forms around the 3d frame.

What causes this and what should be done to get rid of this bump?

Problems Bow.3dm (4.1 MB)

After playing several hours, I came up with flattening the for and aft curves, use tweencurve, extruded the result, intersected with the horizontal frames, then created a new vertical curve with this odd shape. That appears to get rid of the bump.

However, i’d still be curious to know why the bump gets there in teh first place.

This tutorial includes a bow shape modeling process that is a bit different. It might be instructional for your situation: