Thank you for your explanation but for example for making a curved ramp that gets up and back down, what I do is to place vertical lines down at the ends of the profile curve and another vertical line where i want the upper part of the ramp. Then taking the upper edge of the resulting surface, I make a second sweep for giving that profile a width. Thats how I tried to make the ramp i showed above. The question is, how can the scaling rail be used in that situation?