Loft Error - Tangent and Self Intersection

[neinspam2XVWZ]

I have a propeller with multiple cross sections (profiles).  I'm attempting to loft between the x-sections.

Because it is a vintage scimitar shape I'm using two rails (spline) to shape along the length of the prop.  5 of 6 loft sections work as expected.   I don't understand why the middle section does not.  Rail one works in both cases, adding the second rail generates the error.

1) If the spline/rail #2 is full length of the prop I get "rails cannot be tangent to profile" just for the one section

2) If the spline/rail #2 is only drawn between the two cross sections I get "Loft would intersect itself".  This one does not make sense to me, the two sections are parallel faces.

The two cross sections and rails are successfully used to create the loft sections before after the problem one.  What are the errors really trying to tel me is wrong.

[jhackney1972]

Please attach your model.  If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

[neinspam2XVWZ]

If I take the cross sections and split into two, lead edge and trail edge I can loft with a rail.  The problem is that it now leaves a void between the two bodies.

[aliobidi]

Hi, 

just change tangent edges to keep 
your file below 

[TrippyLighting]

@aliobidi have you tried combining these bodies into a single object?

[TrippyLighting]

to get at least a contiguous loft, I would leave out the first section with the rectangle :

However, even the surface quality of this loft leaves to be desired.

There are two reasons for this:

1. The curvature combs of the profiles and rails are less than ideal:

2. You are using too many rails. This loft below only uses three:

the rectangular section would then loft separately  and move the twist control or mapping handles to get better shape control:

[aliobidi]

I re-loft them 

[neinspam2XVWZ]

All,

I just got back from vacation so I wasn't ignoring this thread.

I appreciate all the effort and feedback.  I'll be looking this more closely this weekend.

again Thx!!