Hi Rudy, it looks like the cause of your problem is that the different parts of your shape curves do not touch each other:



That's the middle one where there is a space between the 2 halves. It looks like one on the end may touch ends on one side, but then not be aligned on the other side - surfaces created through these kinds of curves will not create a clean "cap" at the end.

I'll post an example of what you can try instead in a minute.

- Michael