Simple answer: If you didn't see the 3 heads moving, you may have overtightened the screws.
Literary answer: If you saw three heads moving you might be dead, since the only three-headed beast I know is Cerberus, the guard dog of the Underworld...
Unfortunately you're not likely to find the parts that you need to replace that cutter that unit brand new is not sold for more than about $30 I would simply suggest that you replace it since you cannot get the parts to service the razer
