Largest 3D printed item thus far: a 10 hour print that worked without glitches; what an accomplishment!
designed in OpenSCAD:
difference(){ for ( i = [0:5]){ intersection(){ translate([-75, -75, 3 + 20 * i]){ cube([150,150,40]);} translate([0,0,50 + 20 * i]){ sphere(r = 65 + 3 * i , $fn=11);} } } translate([0, 0, 82]){ cylinder(r1 = 40, r2 = 76, h = 150, center = true, $fn = 11);} cylinder(r = 20, h = 40, center = true); }