a sensor mechanism for scanning the ends to determine whether each end extends parallel to {HEAD ~ the path} without {TAIL ~ regard} to the length of the piece being scanned; and 
without
a sensor mechanism for scanning the ends to determine whether each end extends parallel to { HEAD ~ the path } without { TAIL ~ regard } to the length of the piece being scanned ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH