I want you to try a program, called, "Rhino". I am pretty sure that you will like it.
Download at Rhino3d.com
It is free only 25 times for save as.
So you do not have to save the raw file.
Just render it out to be picture file.
For basic thing as I have done, I believe that you can know within 1 hour.
It is really good to make any kind of curve.