+ // central hole in the base plate
+ translate([0, 0, -eps]) scale ([1, base_l/base_w, 1])
+ cylinder(r = base_w/6, h = thin_wall+2*eps);
+ // side holes in the base plate
+ for (y = [-1, 1])
+ for (x = [-1, 1])
+ scale([x, y, 1])
+ translate([0.3*base_w, 0.3*base_l, -eps])
+ cylinder(r = base_w/10, h = thin_wall+2*eps);