$fn=25; width=300; height=210; middleR=30; projection(cut = true){ difference(){ cube([width,height,5]); translate([width/2,height/2,0]){ cylinder(r=middleR, h=5); } translate([width/2-60,height/2-30,0]){ cylinder(r=5, h=5); } translate([width/2-65,height/2+40,0]){ cylinder(r=5, h=5); } translate([width/2,height/2+65,0]){ cylinder(r=5, h=5); } translate([width/2+60,height/2-30,0]){ cylinder(r=5, h=5); } translate([width/2+65,height/2+40,0]){ cylinder(r=5, h=5); } } }