var t_wood = 5.5; var width = 100; var height = 50; function main() { return difference( difference( cube({size:[width,t_wood,height],center:true}), cube({size:[t_wood,t_wood,10],center:true}).translate([width/2-t_wood/2,0,height/2-t_wood-5]) ), cube({size:[t_wood,t_wood,10],center:true}).translate([width/2-t_wood/2,0,-height/2+t_wood+5]) ); }