I have this wing design that I want to print:
You can notice that its walls have a thickness, which is 1.0 mm. I want to print it so that the perimeters are inside that thickness. Here is the wing sliced with 1 perimeter and 0% infill:
You can notice a gap between the perimeters. That gap is what I want filled and not the perimeters in the image. With 0 perimeters and 100% infill I got this zig-zagged line:
I want the gap to be filled; but, I don't want it to be zig-zagged like in the image. I want it to be smooth like the perimeters in the other image.
Basically I want a smooth infill that goes around the curves just like the perimeters. The reason why I don't want to print both the perimeters and the infill is because I want to save as much weight a possible as this is a wing of a model plane that must fly, so the lighter it is the more efficient it will be.
Any ideas how I can slice this?
The images are screenshots in Slic3r, but I can use Cura as well. This is just a test slice. The wing model is not finished yet.
Consider to create a test print using the settings you've presented in the sliced output rendering. It could be something as small as a 4 or 5 mm tall cross section, enough to get clear of the bed and establish a stable base. You may find that your goal is achieved.
Also consider that a common nozzle diameter is 0.4 mm and with an extrusion multiplier, you may not reach a clean integer combination. That is to say, a 0.4 mm nozzle and a 1.05 extrusion factor results in (theoretically) a build thickness of 0.42 mm. Take two of those and you have 0.84, but three of them are 1.26 mm.
You can increase number of wall thicknesses or reduce them as needed to avoid infill or the attempt by the printer to create infill. It may be necessary to adjust your model parameters to achieve a clean combination.
I know that Slic3r supports concentric infill, which will effectively trace the walls rather than turn them into zig-zag shapes. On a base layer, having such a pattern may make for a weaker layer, but you can adjust so many things in that respect that you should be able to accomplish your objective.
Experimentation is useful in a situation such as this. What Slic3r shows you isn't necessarily what will hit the bed.