Hi GenX, it can help if you attach a 3DM file with your curves in it instead of only a screenshot. Like for example in this case it would be good to be able to zoom into your tip area and be able to see more clearly what exactly is going on in that area of your model.

What kind of sweep are you doing exactly? There are a few different variations like "one rail sweep with a scaling rail added", or "two rail sweep" or "two rail sweep with a scaling rail".

I would zoom in and take a close look at the tip area to make sure the curves are touching there, if they are not aligned with one stretching out a little ways past the other it can make for bad results similar to what you show there.

- Michael