difference() {
	cube( size=[55,40,5], center=true);
	cube( size=[45,30,7], center=true);
}

translate( v=[17.5, 15, 2.5] ) {
	cube( size=[10,5,20] );
}

translate( v=[-27.5, 15, 2.5] ) {
	cube( size=[10,5,20] );
}

translate( v=[17.5, -20, 2.5] ) {
	cube( size=[10,5,50] );
}


translate( v=[-27.5, -20, 2.5] ) {
	cube( size=[10,5,50] );
}

translate( v=[-5, -20, 2.5] ) {
	cube( size=[10,5,50] );
}
translate( v=[-27.5,-20, 47.5] ) {
cube( size=[55,5,5]);
}