OpenSCAD $fn=50; difference(){ minkowski(){ sphere(1); hull(){ cylinder(h=1,d=25,center=true); translate([100,0,0]){cylinder(h=1,d=25,center=true);} translate([50,30,0]){cylinder(h=1,d=20,center=true);} translate([50,-30,0]){cylinder(h=1,d=20,center=true);} } }translate([50,0,-4]){cylinder(h=8,d