--- /dev/null
+infty = 100;
+eps = 0.01;
+
+diameter = 20;
+thick = 2;
+d_minus = thick/2; // cca 45 deg
+
+center_hole_d = 3;
+side_holes = 5;
+side_hole_d = 5;
+
+module body() {
+ cylinder(r1 = diameter/2, r2 = diameter/2-d_minus/2, h = thick/2 + eps);
+ translate([0, 0, thick/2-eps])
+ cylinder(r2 = diameter/2, r1 = diameter/2-d_minus/2, h = thick/2 + eps);
+}
+
+difference() {
+ body($fn = 128);
+ translate([0, 0, -eps])
+ cylinder(r = center_hole_d/2, h = thick + 2*eps);
+ if (side_holes > 0)
+ for (angle = [0:360/side_holes:360]) rotate([0, 0, angle])
+ translate([diameter/4 - d_minus + center_hole_d/2, 0, -eps])
+ cylinder(r = side_hole_d/2, h = thick + 2*eps);
+}