解答： 將 fillScene() cube.rotation 以下替換成：

var minuteHand = new THREE.Object3D();
minuteHand.add( cube );

minuteHand.rotation.y = -60 * Math.PI/180;
scene.add( minuteHand );

var sphere = new THREE.Mesh( new THREE.SphereGeometry( 0.5, 32, 16 ), hourHandMaterial );
sphere.position.y = 18;    // move the hand above the other hand

sphere.scale.x = 50;
sphere.scale.y = 4;
sphere.scale.z = 4;
sphere.position.x = 50/2 - 10;

var hourHand = new THREE.Object3D();
hourHand.add( sphere );

hourHand.rotation.y = 30 * Math.PI/180;
scene.add( hourHand );