lengthL=100; widthL=10; lengthT=lengthL-widthL; pinD=3; $fn=30; module linkageWhole(){ difference(){ hull(){ circle(d=widthL); translate([lengthT,0]) circle(d=widthL); } circle(d=pinD); translate([lengthT,0]) circle(d=pinD); } } linkageWhole();