This thing was made in OpenSCAD with the following code: translate([0,0,-10])cylinder(30,1,10); translate([40,0,-10])cylinder(30,1,10); translate([0,40,-10])cylinder(30,1,10); translate([40,40,-10])cylinder(30,1,10); cube([40,1,20]); difference() { translate([0,40,0])cube([40,1,20]); rotate([90,0,0]) translate([20,20,-60])cylinder(50,8,8); } cube([1,40,20]); translate([40,0,0])cube([1,40,20]); translate([-10,-10,20])cube([60,60,1]); difference() { translate([0,0,-10])cylinder(6,10,10); translate([0,0,-10])cylinder(3,9,9); } difference() { translate([0,40,-10])cylinder(6,10,10); translate([0,40,-10])cylinder(3,9,9); } difference() { translate([40,0,-10])cylinder(6,10,10); translate([40,0,-10])cylinder(3,9,9); } difference() { translate([40,40,-10])cylinder(6,10,10); translate([40,40,-10])cylinder(3,9,9); } translate([20,20,10])cube([5,10,5]);Whether you need supports depends on your 3D printer.