use <lib/smooth_prim.scad>

HEIGHT=10; // mm
WIDTH=10; // mm
LOBE_THICKNESS = 6; // mm
THICKNESS=(WIDTH-LOBE_THICKNESS)/2; // mm


difference() {
SmoothHollowCube(HEIGHT, THICKNESS, 0);
translate([2,0,0]) {
SmoothWall(LOBE_THICKNESS, HEIGHT+2, THICKNESS);
};
}