Need help sorting out Loft functionality

Jekle

I'm about to pull out whatever hair I've got left, I just can't seem to get Loft working no matter what I try.
I want the inner profile normal to profile, resolving in the outer profile tangentially. 
I've tried forever to play around with the other functions, but I just can't seem to make it work. What am I not understanding about this?

S1mon

If you want to share a public document, it will be easier to help.

In general, profile generator creates splines with way too many control points which can cause some issues. However, in this case the issue is likely because the trailing edge comes to a sharp point, and being tangent to profile on both sides of that point at the same time is likely to fail due to self intersection.

Here's a simple loft with two different circles, which works with the Normal to profile and Tangent to profile constraints:


Here's a loft based on some very simplified airfoil sketches which are very smooth (degree-4 Béziers on top and bottom), and while I can get the loft to work, the result at the leading edge is not what you'd want.

To clean that up, I needed to add guide curves and a temporary surface to control the tangency of the leading edge, and I did this with surfaces instead of solid lofts. To have more control over the shape, you might need more guides.

https://cad.onshape.com/documents/59b989f93ef18de2f4f34200/w/a4a7a64da17a283eca534892/e/3ddb92a108ca4ab04cd6f1d0

Ultimately, I question using Tangent to profile, since this creates a shape that tapers to nothing. This is not really manufacturable. You probably want some thickness there, or to have the surface hit the tip at less than 180 degrees.