When the switching means causes {HEAD ~ the motor} to spin, the disks free {TAIL ~ spin} around the motor shaft 
When the switching means causes { HEAD ~ the motor } to spin , the disks free { TAIL ~ spin } around the motor shaft
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH