+x_B_r = d_OB_r * cosa;
+y_B_r = -dy_OB_r;
+
+x_T_r = sina;
+y_T_r = -tana * sina;
+
+wall_x_r = wall_r / tan(90-alpha);
+
+top = wall_r * r1 - (d_OC_r - 1) * r0;
+basew = base_r * rnom;
+
+echo("dias", r0*2, r1*2, "ratio",r1/r0);
+
+module CrossSectionHalf(plus=0) {
+ difference(){
+ polygon([[-0.1, y_T_r * r0],
+ [x_T_r * r0, y_T_r * r0],
+ [x_B_r * r1, y_B_r * r1],
+ [x_B_r * r1 + wall_x_r * rnom + plus, y_B_r * r1],
+ [basew + plus, top],
+ [-0.1, top]]);
+ translate([0, -d_OC_r * r0])
+ circle(r = r0);
+ }
+}
+
+module CrossSection(plus=0) {
+ for (m=[0,1]) {
+ mirror([m,0])
+ CrossSectionHalf(plus);