Lofting an elliptical wingtip.

Good evening everybody!

I am trying to design a wingtip for an aircraft I am trying to build. It will be a very low cost "FPV" platform with elliptical wingtips. I could work with the current wingtips, but I am not sure why they wont conform to the guide curve.Image result for raked wing This is what it currently looks like, its OK.

Image result for Spitfire wing

I am preferring to use a more efficient elliptical wingtip that looks cooler and conforms better.

This system does not really work right now.

Can somebody help me out?

SolidworksEducator Student