{TAIL ~ An elevation drive unit} supported by the θ drive elevates/lowers {HEAD ~ an elevation frame} under the control of an elevation control unit 
{ TAIL ~ An elevation drive unit } supported by the θ drive elevates / lowers { HEAD ~ an elevation frame } under the control of an elevation control unit
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH