difference(){ translate([0,2,0]) rotate([0,90,90]) cylinder(6,6,6,$fn = 100); translate ([0,-1,0]) sphere (6.2,1,9,$fn=100); rotate([0,90,90]) cylinder (8.5,0.5,1.5,$fn=100) ; translate ([-2.5,2.0,2.5]) rotate ([0,90,90]) cylinder (8.5,1.5,1.5,$fn=100); translate ([2.5,2.0,2.5]) rotate ([0,90,90]) cylinder (8.5,1.5,1.5,$fn=100); translate ([2.5,2.0,-2.5]) rotate ([0,90,90]) cylinder (8.5,1.5,1.5,$fn=100); translate ([-2.5,2.0,-2.5]) rotate ([0,90,90]) cylinder (8.5,1.5,1.5,$fn=100); }