To ensure {HEAD ~ the platform} follows {TAIL ~ a linear path} in the Y direction without Z axis deviation, one or more embodiments of the invention contemplate the use of a computer control system 
follows
To ensure { HEAD ~ the platform } follows { TAIL ~ a linear path } in the Y direction without Z axis deviation , one or more embodiments of the invention contemplate the use of a computer control system
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH