Simple loft "would intersect itself". How is it possible?

[josip.andresic]

Hello to everyone. I have a problem with a very simple loft. At least, to me it seems simple, to Fusion it is a selfintersecting loft.

I really don't know what could be the problem. Sketch profiles I want to loft are trapezoids with rounded edges, they are on perfectly parallel planes, one above the other, they are same shape, just that one is offset by a couple of milimeters. Otherwise I'd have used extrude.

Screenshot is in attachment. I circled the problematic loft. It lofts with any other sketch, but not with this one.

I even removed the inner outline of upper sketch because sometimes it didn't want to loft with sketches that look like that.

Thanks,

Josip.

[davebYYPCU]

Will need the file to investigate, 

some things to look for, duplicate sketch articles overlapping?, 

yellow warnings for either sketch?,

hide the other clutter, in case the selections are being confused,

do you get a preview?, check for crossing mapping handles.

Might help....

[josip.andresic]

Thank you for a very quick answer. I'll look for these warnings. There's no preview of loft, only the warning message. I will give you the file when I get to it, but it's a real mess for it's an old project that was done poorly and I started to upgrade it and work on existing features that were bad.

[josip.andresic]

In the end, I managed to solve the problem by using a centerline rail. It was a line that followed the perfect central axis through both sketch profiles.

I guess there were more possible solutions a program could make for the loft, given the sketch shapes were not symetric, so it needed a guide on which way to go?