Here I have made 5 cv curves.
Notice:
1. all the start cv's (the boxes) are aligned.
2. all the curves have the same direction vector (the line from the box to the U shape)
3. all the curves have the same number of cv's
4. all the cv's are spaced uniformly
Before lofting each curve must be selected in order. Drag selecting will give unpredictable results.

and here is the loft:
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675