r = 0.5;
R = 2;
z = 1;

Point(10) = {0,0,0};

Point(11) = {0,r,0};
Point(12) = {0,-r,0};

Point(13) = {0,R,0};
Point(14) = {0,-R,0};

Point(15) = {r,0,0};
Point(16) = {-r,0,0};
Point(17) = {R,0,0};
Point(18) = {-R,0,0};

Circle(1) = {13, 10, 18};
Circle(2) = {18, 10, 14};
Circle(3) = {14, 10, 17};
Circle(4) = {17, 10, 13};
Circle(5) = {11, 10, 16};
Circle(6) = {16, 10, 12};
Circle(7) = {12, 10, 15};
Circle(8) = {15, 10, 11};
Line(9) = {11, 13};
Line(10) = {12, 14};
Line Loop(11) = {9, 1, 2, -10, -6, -5};
Plane Surface(12) = {11};
Line Loop(13) = {10, 3, 4, -9, -8, -7};
Plane Surface(14) = {13};


Transfinite Line{1:8} = 6/2;
Transfinite Line{9,10} = 6;
Transfinite Surface {12,14} = {13,14,12,11};
Recombine Surface '*';

Extrude{0,0,z}{Surface{12,14}; Layers{4,1} ; Recombine;}


