$fn=200; length = 86; width= 46; height = 19; cornerRadius = 10; translate([10, 10, 0]){ difference() { roundedBox(length, width, height, cornerRadius); translate([1,1,1]) { roundedBox(length-2, width-2, height-1, cornerRadius); } } } module roundedBox(length, width, height, radius) { dRadius = 2*radius; //cube bottom right translate([width-dRadius,-radius,0]) { cube(size=[radius,radius,height+0.01]); } //cube top left translate([-radius,length-dRadius,0]) { cube(size=[radius,radius,height+0.01]); } //base rounded shape minkowski() { cube(size=[width-dRadius,length-dRadius, height]); cylinder(r=radius, h=0.01); } }