translate( v=[0,0,10] ) {
difference() {
union() {
rotate( a=60, v=[1,0,0] ) {
translate( v=[-5,0,0] ) {
difference() {
cylinder( r=15, h=4, $fn=50 );
cylinder( r=10, h=4, $fn=50 );
}
}
}
rotate( a=-60, v=[1,0,0] ) {
translate( v=[5,0,0] ) {
difference() {
cylinder( r=15, h=4, $fn=50 );
cylinder( r=10, h=4, $fn=50 );
}
}
}
}
translate( v=[-15,-15, -20]) {
	cube( size=[30,30,10] );
}
}

}